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Chapter 5 - Database Design and Setup
In This Chapter
Introduction 5. 1
N Logical Database Design 5-2
Logical Database Design Methodology 5-4
Logical Database Design Products 5-5
Physical Database Design 5-8
Data Migration 5. 11
Introduction
It is highly recommended that Indian River County conduct a full database design .
Although the Property Appraiser ' s Office has an enterprise geodatabase ( ArcSDE/Oracle) ,
the County will need to develop a full enterprise GIS database ( geodatabase ) to manage
and maintain a variety of GIS data . In order to effectively address this need , the following
components of the Database Design process are recommended for the County :
1 . Logical Database Design
2 . Physical Database Design
3. Data Migration
4. Database Setup and Administration
Given the County ' s distributed management and maintenance of GIS data layers
throughout various departments and offices, it is recommended that these GIS data layers
be consolidated to a centralized database that can be accessed through the County ' s
network.
Consolidation and centralization of key GIS data layers, such as the County ' s base map
layers (tax parcels , street centerlines , and aerial photography) will eliminate the use of
duplicate, redundant GIS data layers (see Chapter 4: Base Map Layers for more
information ) . A centralized GIS data environment will also streamline data maintenance
efforts and ensure that control and access to the data can be managed more easily .
Special consideration will be needed to ensure that the County ' s enterprise database
integrates existing departmental databases as well as other enterprise databases as much
as possible . In order to implement a hybrid centralized/decentralized GIS data maintenance
model (see Chapter 2 : GIS Organizational Structure ) , it is recommended that departments
that currently manage and maintain GIS data in enterprise databases ( e . g . , Property
Appraiser ' s Office) should continue to have ownership of the data . Based on this model , it
may be viable to have County departments access several enterprise-level databases
( geodatabases) through the County ' s network . However, if this model is not viable, it is
recommended that a read-only copy of that data maintained in the recommended
centralized enterprise database .
" The " centralized access " model will require an automated mechanism that will aggregate
distributed data and create read-only centralized copies on a regularly scheduled basis
5- 1
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
( e .g . , nightly) . The " distributed access " model will require robust network connectivity and a
means for various users to access the data (e .g . , Intranet GIS data browser) . The centralized
access model can be used by any application that has network access to the enterprise
database; the distributed access model requires applications network access to several
databases as well as functionality that allows access to various data sources at once .
" Distributed Access " Model "Centralized Access" Model
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Figure 5- l : Database Access Options for Indian River County
Based on the County ' s existing network infrastructure and configuration , it is recommended
that in the short term a centralized data access model should be implemented—however,
as the County ' s GIS implementation progresses , it is recommended that the County develop
the proper and necessary network infrastructure and configuration to establish a distributed
data access model .
Regardless of which model the County implements, a logical database design effort will be
needed in order to properly implement a centralized enterprise GIS database . Subsequent
logical database revisions may be needed as GIS data needs evolve and /or as the County
modifies its GIS database model .
ItLogical Database Design
Why conduct a logical database design2
The logical database design process can be time consuming and produces no end -use
applications . Therefore , the logical design process often receives limited attention , if any.
However, there may be risks associated with not conducting a logical database design . By
not going through the logical design process , Indian River County risks having a poorly
y constructed database that does not meet present or future requirements . Poor database
design can result in duplicate , missing, or unnecessary data ; inappropriate representation of
data ; or lack of proper data management techniques .
v 5-2
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
One of the key aspects of a successful GIS implementation is good database design . Asking
the right questions ultimately leads to a good database design :
• How can GIS technology be implemented to streamline existing functions , or change
the way a particular goal is achieved ?
• What data will benefit Indian River County most ?
• What data can be stored ?
• Who is , or should be , responsible for maintaining the database ?
How the County answers these questions will improve its understanding of GIS technology, as
well as provide new insight into the organization and its functions .
A good database design results in a well-constructed , functional , and operationally efficient
database that :
• Satisfies objectives and supports organizational requirements
• Contains all necessary data without redundancy
• Organizes data for different users with various access levels
Accommodates different views of data
Identifies and distinguishes applications that maintain data from those that use it
• Appropriately represents, codes, and organizes geographic features
• Enforces rules for how geographic features interact
Benefits of the database design process include :
• Increased flexibility of data retrieval and analysis
• Distributed costs of data capture , storage , and use
" 0 Versatile data that supports many different uses
• Maintained data that supports many different users
• Extendibility that readily and easily accommodates future functionality
• Reduced data duplication and data archiving
The key task in building a logical data model is to precisely define the set of objects of
interest and to identify the relationships between these objects . Once an initial logical data
model is developed , it should be validated against Indian River County users ' requirements
for entering , updating , and accessing data , and by testing it against the organization ' s
practices and procedures dor business rules) .
It is critical to involve representatives from each County department/division that will utilize
the data . A logical data model built for a subset of users is guaranteed to have deficiencies
for unidentified users . Building a logical data model is an iterative process and an art that is
acquired through experience . There is no single " correct ' model , but there are good
models and there are bad models . It is difficult to determine when a model is correct and
complete, but an indication for this is when Indian River County can answer `yes ' to these
questions :
• Does the logical data model represent all data without duplication ?
• Does the logical data model support Indian River County ' s business rules?
• Does the logical data model accommodate different views of data for distinct
groups of users ?
5-3
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
eLogical Database Design Methodology
The Logical Database Design should consist of four parts :
1 . Kickoff Meeting
2. Existing data acquisition and review
3. Interviews
4. Logical Database Design
Kickoff Meeting
Kickoff meeting attendees should include all Indian River County personnel that currently or
will in the future:
• Create spatial data
• Provide input on the creation , updating or use of spatial data
• Use spatial data on a regular basis .
The kickoff meeting should introduce the goals and objectives of this project, outline how the
project will be conducted , and inform attendees of what will be required of each them .
Existing Data Acquisition and Review
Before the Logical Database Design process can move forward , Indian River County will
need to ensure that if has a copy of all existing County data layers and source data from
each department that will be included in the database design .
Interviews
All pertinent staff members from each County department/division should be interviewed .
Interviews can be conducted separately for each department, or in logical groupings . The
goal of each interview is to discuss in detail each data layer for which attendees are the
Subject Matter Expert .
Issues that should be discussed include :
Deletion of existing attribute fields
w0 Addition of new attribute fields
• Allowable values for important attribute fields
• Relationship of layer to other layers
• Associated tables and cardinality
• Description or alias of each field (when not obvious)
• Subtypes
• Default values
• Whether null values are allowed or not
• Indexes
Several important metadata aspects ( not documented or available from the earlier existing
data acquisition ) to include ( but not limited to) should be documented , including :
• Feature Class Name
• Feature Class Type ( point, line , polygon or raster)
Feature Dataset
• Description
• Purpose
• Data source
54
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
• Primary and secondary data custodians
• Acquisition scale and accuracy
• Spatial information ( projection , coordinate system , datum , units, etc .)
• Status of the data ( complete , incomplete, etc . )
• Data update frequency
Constraints on accessing and using the data
• Point of contact for each layer
KtLogical Database Design Products
The logical database design process should result in two products :
1 . Printed documents
2 . Flow Chart drawings
1 . Printed document
A printed and bound database design document should be developed . The
database design document should individually document each data layer that will be
included in the process . Important metadata about each layer should be
documented at the top of each sheet, as well as a snapshot of what the layer looks
like visually ( Figure 5-2) . Every attribute field should be listed , to include :
• Field Name
• Description ( of the field)
• Data Type (string , date, integer, etc, J
., a Allows Nulls (whether null values are allowed or not)
• Default Value (if appropriate )
• Domain (reference to domain that dictates allowed values for this field )
• Length ( number of characters allowed )
• Precision ( number of allowable significant digits)
• Scale ( number of allowable decimal places)
Index (whether a field is indexed )
5-5
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
Potable Water Valves - --- -- -
Feama Clas Name: PotebkWaterVebes -
Featus DaAret PotaUleWaterDisvbNiorS�;rstem
Feat• a Clan Type: Poutl
Data Soytrve: 2072 GPS Data Cotlecvon
Primaq Cwbdim Michelle Wang - SIS Techres an - FIS rG15
Accuracy: +(- t merely
Projection: NO Stale Plane, NAD83, feet - - -.
SIalm: Cocgilete as cfEtecim, 20.03
Daft Update Frequeney: As charges are made in the fie:d _
Conanabrv: Data marr NOTbe released to the public -
PointofContact: Katieeine O'Breen-FJSIGIS (919) 123"4567, KOBrkr�fac am Pica
Description: Feud Layer of water Saba hications.
Purpose: Inventory of ell campus pe[ebk vretervahres
Attributer:
reld Name Daft Allaxr fait Do idan 7< Dereriptian
typeN•LL Value
BypasVaM hall Yes 0 Bocleas 0 p 2 "n ULZs if ihe :alve has a wypassvaive for
Integer
memte ame
CbckwiseToClore Small
:rote r Yes 1 Boolean 0 U 2 Doesthe valve close in a nbckwise diedione
teal
" CwrenL`yOpen Integer Yrs L Boolean 0 0 2 Is the vahm. cuvenBy epenP
Motorcycled Indo Yes 0 Boolean ] 0 Is the valve mctorriedP
Nommlly-0pec oral Yes I Bookan 0 1 2 s the valve designed to be aper under novm:
Into r mtwark clmummaer
"> Percent n Into ,r as 100 0 Fane Nom Cuven[ oerent en
Pressvresatt
Sinns SinnYes Vote Nona 20 f-urentp,ressvre self
Pegulat»nType Stung Yes WHSyetamVaUaReq�uaz Type Hong i Nom 20 aY9he�k) S1QP regulation performed (d
TvrzsTrCbse fire Yes 0 Nom Ham Number tUturmre coredt idose tie vabe
Diameter lntee[ Yes 10 Ma es illi. 'iarrzlei 0 Nom Nam Diameter of[hr Babe
Bkvation Double Yes 1 0 None7ktmnofthevalve
WaterT e Str = Yes potable Waterh e Nom Noce 20 T eofweterflowt. item the systera
AdmniistMiveAree St Yes N AdmutislratrseArea Nona None 200 ' The vlrvnmtmGre area thet m:eems the object
Fecilitym 51- Yes Nom Nom I 20 IAumque facility number for4m object
:mtallDate Date Yes UJ
S Date object
was wlalkdmtie ori
Lo:atlomDescrt on Stc Nom 9cm 200 Tei3desca ion. off�e locatmn
OparetiomL4r_a String Yes Dl OpemimgArea None INam 200 Fx�gneermg or operational Cvtrict for [he
Rotation Double Yes 0 U None Rotation angle ( may svmbolo�
Likc lestates It Yes Active IGfeC ,kStetvs Nom Nom A St of the fazilit lifec k
sibT e tine r Vas 1 IG Nom Nom T. of feature
WorkOtdedD st Yes Nom Nom 2U
Am Rule Inte r Yzs 0 Nom Nom
Enabled °tTBII Yes 1 Fn,hkd 0 ] - ✓✓ark Order dot imtelled the ab act
Integer j
Figure 5-2: Example Printed Logical Database Design Sheet
2. Flow Chart Drawings
Data model flow charts for the organization of each data layer within the
geodatabase should be developed . Developed products should include individual
printed drawings , digital drawings in MS Visio format , as well as digital images of each
drawing .
Data should be logically organized into the following categories :
• Geodatabase
• Feature Datasets
• Feature Classes
Geodatabases should be utilized to organize similar datasets. Feature Datasets should
be established to logically group Feature Classes of similar type or business process .
The data model flow charts should document all Feature Datasets, and the Feature
Classes within each Feature Dataset ( Figure 5-3) . Feature Classes should be displayed
according to type: point, line , or polygon . Additionally, the organization of other types
ry of data that will be stored within the geodatabase, including ( but not limited to) rasters
(such as aerial photography) , and CAD data , should be documented .
5-6
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
Geodatabase
Feature Dataset Feature Dataset Feature Dataset Raster Catalog
Feature Data Feature Data Feature Data Featwe Data Feature Data , Feature Data
CIOSs
Class Class Class Class Class Raster Images
Figure 5-3: Diagram Of Overall Logical Database Design
Each Feature Class in the Data Model Flow Chart should further display all attribute
fields ( Figure 5-4) . Other information that should be documented , when necessary ,
includes :
e Abstract Classes - a device for documented common attribute fields used by
more than one subsequent Feature Class , to avoid redundancy .
Subtypes - variations of similar features
e Domains - allowable values for an attribute field
Cardinality - relationships between feature classes , or between feature classes
and objects ( tables)
57
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
MainLine
ExlerbCoating
JoinTYpe (2(
Liningiype
Pipecloss Abstract Roughness
Cardinality
t
u PressunzedMain GrovifyMoin Grovitylvain
Feature Shapes
Depth BareCount
Darrel Class CrossSectionShape
GroundSurtaceType Upstreaminvert
PressureRating Downstreaminverl
Measurement (2)
Domain
Blowoff Interconnect
Carner Coded value domain
Bypass Pipearidge GravityMainShapes
Description
In Cine Storage
Field type Srring
AirRelease
Soupolicy Default Value
SampiingSfation Merge policy Duplicate
Pipe
r
CheCircular Circular
Cheri
on Transmission Matn Horseshoe Horseshoe
Oblong Oblong
Unknown Unknown
DistnbutionMaln Subtypes
Figure 5-4: Example Section of a Logical Database Design Data Model Flow Chart
KtPhysical Database Design
A physical data model must be created after the logical data model is complete . The
Physical Database Design consists of implementing the logical data model schema within
the geodatabase . This entails physically creating all of the features designed in the Logical
Data Model .
n This is the final step before the migration of existing data to the geodatabase . Therefore , a
decision must be made with regard to which data layers should be represented in the
geodatabase once the initial geodatabase is created . The County currently has a
substantial number of spatial data layers. Most of these data layers will be relatively easy to
migrate , although some layers will require more effort , including conversion and
consolidation .
A Indian River County should consider the following criteria when it has identified layers to
implement in the Physical Database Design during initial implementation :
• The County may wish to restrict access to some data layers until an agreed-upon
level of completeness or accuracy is achieved
• Data layers may require a customized data model provided by a software vendor
• Users may be more comfortable with the existing format of data layers, or users may
not have received training on utilizing data stored in a geodatabase
58
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
It is recommended that Indian River County assess all of the aforementioned points of
consideration during the Logical Database Design prior to moving forward with the Physical
Database Design for those layers that are deemed appropriate, based on the assessment.
Once the County decides which data layers should be migrated to or created in the
geodatabase , these features can be physically created within or migrated to the
geodatabase . A data layer does not need to have been created for that layer ' s physical
design to move forward . Empty Feature Classes can be created , which can be populated
with actual data at a later point. Figure 5-5 shows many of the types of features that must
be created within the Physical Database Design process . The geodatabase itself stores
information on domains .
Geodatabase
�11 Feature Dataset
LEIJJ Polygon Feature Class
Line Feature Class (Edge when part of a Geometric Network)
Point Feature Class (Junction when part of a Geometric Network)
Al Annotation Feature Class
Geometric Network
Relationship
Table
�- Topology
Figure 5-5: Features that will be created during the Physical Database Design
5-9
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
Domains should be created within the geodatabase J
according to the Logical Database Design specifications . nma om,e� l
According to the agreed upon Logical Database Design , I
Feature Datasets should be created . Figure 5-6 displ
Jays domains created for a geodatabase, domainro erties,
P P ID�W"MI and values (in this case, coded values) . _��„my� �,=,M
JJ
Within Feature Datasets , Feature Classes should be .dm„ Prdoerr,
K created . Feature Classes should be created accordingto `"'°
Pam,rTypIm die=
the agreed upon Logical Database Design . Important SOODOO, w
information about each Feature Class that must be
e ,..
created includes: Name and Alias ( Fig . 5-7 ) ; Fields - to J
include Field Name, Data Type, Alias, Allow Null Values ,
�a oe,<,gwn
Default Value, Domain , Precision , Scale , and Length ( Fig . 5-
8) ; IndexesFi ; Subtypes
19 5-9 ] ypes ( Fig . 5- 10) ; and Relationships �-�, add-P
( Fig . 5- 11 ) . 4LT
OK Cam _�
Figure 5-6: Creating
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sw�eeo,.ro. W191a
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TYPI
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mI 3
ie dta rtwreM, r mYe mee Ne en em uw n Ne etlNme Nun,c
�... me oa,e i.er.°�,„,ro cmearxeae mo� � .a,rne r ie
Proo .,
D —J � Jc
Figure 5-6: Feature Class General Figure 5-8: Creating Feature Class Figure 5- 9: Creating Feature Class
Properties Fields and Field Properties Indexes
5- 10
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
ziXi
coal ea� Iw�ae swyw, lRaaorer+ealw n.eowo. l e�dIF6a eslswypa RdMujship, l w84t4e.,0� 1
SWpge FN6 Sibdpe R+efueee c6M pa4gMmir Ue lcbwiy ,eb nntNps:
Delaue 5uhrym Bn.OR fleMurmM1 LeM flebM io qck
N SWrYuev "Ir e4Mm H w_Patas... .Spaual"ei_. Diem
omml� J
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evene
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Figure 5- 10: Creating Feature Class Subtypes Figure 5- 11 : Feature Class Relationships
fihata Migration
Once the Physical Database Design process is complete , existing data can be migrated
from its existing format to the geodatabase . It is highly recommended that this process
occur simultaneously with the database design process . Some data manipulation will be
part of the migration process . Attribute fields from the existing data are matched with its
respective counterpart in a Feature Class in the Physical Database Design . Only fields of
" similar data type can be migrated . Once data layers are in a state conducive for migration ,
ArcCatalog should be used to physically migrate the data from its existing format to the
geodatabase ( Figure 5- 12) .
a Based on countywide needs assessments , it is recommended that data conversion to the
geodafabase format be implemented . The conversion process should be performed in
parallel with migration of existing GIS data layers currently maintained in Shopefile and /or
CAD format . The GIS Director will need to determine the most effective means of converting
existing CAD data . The geodafabase will be used to serve geo-spatial data for the County ' s
enterprise-wide applications , including the Intranet GIS data browser as well as an Internet
GIS data browser.
5- 11
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
X1
For each target field, select the source field that should be loaded into it.
Tai Field MalcYting Source FiHtl
Ancilaryftole [short fill Mcillarykole Isom int]
Enabled ishod loll Enacted Dood intl
AdninistrativeArea [strfngl. AdrnlrvstraliveArea Js iingl
FacT¢ rodrlrg] Paoli [Ani
o IrtslallDate [PATE] _ InslallDale [CATE]
LocallorrDezcriptlon [string] LocetfonDescrlption rpringl
OperetlonalArea [sti ingl OperatlonalArea [slring]
Rotation [double] _ RNation double
LifecycleSYffius [stong] 11clecycleadinus [string]��
C ,li chit
<Noi
Ancillaryftale [short irn]
Enabled [shod art]
Admina-2raliveArea [outing]
FaclfltylD [string]
Lxali s- Descnptbn ]string]
OperationalArea [etring]
Final [double] I
Subtype icor
Figure 5- 12: Data Migration - Simple Data Loader in ArcCatalog
Concurrent with the migration of data, all necessary metadata for each data layer ( Figures
5- 13 and 5- 14) should be documented . Metadata information gathered during the data
acquisition and interview process should be combined with any pertinent metadata
information made available during the database design process .
identification Dna 'pe JJ
puefy Dde Drgmzetlnr Spatial Relemnce Entity Attribute Dutribution Mepirri Reference
General ( Contact I Glalm l Time Period I status I spinal Darren I KeywordaI Browse haptic Security Cross Reference
Description
Abstract DNC -11 Light Poles
Purpose T he location and type dell UNL campus light poles
Language: JT 7h
oupplemenral
Infatuation:
Access no access constraints
Crnslranrs
Use No are mn;lranis
Constraints:
Data Ser
Celt
Nerive Data Set Mloewn Windows 2000Vessurr 5 0 [Bald 2195] SOF ote Pack 2. ESP! ArcCatalog 8 3 BBDO
Environment
Nacre Data set
Parma Per=ona� Geopawnaae Faamact
ea
T Save Cancel Help
Figure 5- 13: Metadata Editor in ArcCatalog
5- 12
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
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et el
51 data YGOindata In vIn" L
rate If
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Figure 5- 14: Descriptive, Spatial, and Attribute Metadota Information of a Feature Class Displayed in
ArcCatalog
5- 13
GIS Needs Assessment and Implementation Plan Chapter 5 - Database Design and Setup
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Chapter 6 - Data Standards and Transfer
In This Chapter
Introduction 6- 1
Data Formats , Coordinate Systems , and Transfer Media 6- 1
Data Format 6-2
Data Formats Table 6-2
Coordinate Systems and Datums 6-3
Coordinate Systems 6-3
Datums 6-4
Coordinate Conversion 6-8
Transfer Media and Backup 6-9
Transfer Media 6-9
Sharing Data Via the Internet 6- 10
Data Creation and Maintenance 6- 11
Roles 6- 11
Data Indexing Strategies 6- 17
Metadafa 6- 17
ArcCatalog 6- 17
Metadafa Recommendations 6-34
Introduction
As noted in Appendix II - Seven Keys to a Successful GIS Implementation, there is a
compelling need to establish good relationships with other organizations to facilitate sharing
of data . No successful GIS can be an island unto itself. Forging partnerships and deciding to
share data with other organizations is only the first step . The next step involves the technical
issues of data sharing .
Once Indian River County has identified data that can be shared , if needs to determine the
mediums , media , and formats that will be used to share that data .
Data Formats, Coordinate Systems, and Transfer Media
As Indian River County proceeds with its GIS implementation , if will find that many
organizations are willing to share data . However, getting viable, quality data may prove to
be a challenge .
There are three discrete issues that must be addressed whenever sharing digital GIS data
with other organizations:
• Data Format
• Coordinate System and Datums
• Transfer Media and Backup
6- 1
GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Data Format
GIS data can be maintained in a number of formats. The format depends on the type of
software used to create the data and the output format an organization uses to distribute its
information . The combination of Arc Editor and ArcView software recommended for use by
Indian River County offers considerable flexibility. There are only a few data formats that
these applications cannot read ) or import) .
Some formats are easier to use than others . The following is a list of common data formats,
their derivation , their ease of use , and whether they can contain tabular ( attribute) data as
well as geographic data .
Data Formats
Format of choice. ArcGIS data
model . Can be exported as
geodatabase, coverage,
export file, shapefile, or others.
ArcGIS ArcGIS: Consists of feature datasets,
Enterprise Arcinfo, High Yes feature classes, tables, etc.
Geodatabase ArcEditor Stored in commercial RDBMS,
and accessed with ArcSDE as
an SDE layer. Allows multi-user
editing and limitless storage
capacity
ArcGIS data model . Can be
exported as geodatabase,
ArcGIS ArcGIS : coverage, export file , shapefile,
Personal ArClnfo, High Yes or others. Consists of feature
Geodatabase Arc Editor, datasets, feature classes,
ArcView tables, etc . Stored in MS
Access database. Limited
storage capacity
1. Previous format of choice for
polygonal data, such as tax
parcels , Native Arcinfo
Workstation file format. Is
Arcinfo comprised of many files,
Coverage Arcinfo High Yes I tabular and geographic . All
files must be copied if this type
of file format is to be used.
Utilizes topology. Not
supported by ArcGIS 8.3
Desktop.
" Format of choice for distribution
of coverages . Contains all of
nfo Export the data in an Arcinfo
Arci
File of of Arcinfo High Yes coverage in one file. This file
format has to be imported but
makes transport of data very
efficient.
Format of choice. Native
ArcView ArcView file format. Easily
ArcView i High Yes
shapefile converted to an Arclnfo
Coverage or Geodatabase.
6.2
GIS Needs Assessment and Implementation Plan Chapter 6 — Data Standards and Transfer
Hard to transfer tabular data .
CADD
DXF Medium Yes Usually obtained from
,. Products engineering firms and surveyors.
Native AutoCAD format.
DWG AutoCAD Medium Yes Arclnfo and ArcView can read
these files without conversion.
Must be converted to a
I Intergraph Low Yes different format for use with
Arclnfo or ArcView
Digital Line Graph data used by
DLG USGS Low Yes the USGS. Often DLG files have
been converted already into a
' more usable format.
Spatial Data Transfer Standard .
Developed by the National
SDTS USGS Low Yes I Mapping Division of the USGS.
Primarily used as a cross-
platform distribution format.
Point and Raster formats
Contains valuable
demographic data . Should be
Census acquired . But the native tiger
Tiger Files Bureau Low Yes file format is cumbersome and
difficult to translate . Try to find
a state agency that has done
the conversion already.
Used for the generation of
elevation contours.
DEM Digital Various Cumbersome to use but often
Elevation Sources Low very Little necessary. Requires ArcGIS
Model Spatial Analyst to utilize raster
data.
MrSID and GeoTIFF are formai
F, Sun Raster, of choice. Various image
TIFF,
BMP, BIL, Various formats that can be displayed
JFIGIF, JPEG, Sources Low No directly in ArcGIS and
MrSID AutoCAD . Useful for display,
aerial imagery and
photographs.
Whenever possible, data should be obtained in ArcGIS geodatabase , ArcView Shapefile , or
AutoCAD (with object data ) format . These formats are the easiest to use . GIS datasets are
usually large and will require data transfer by tape , compact disc , or via the Internet . Data
can be supplied on CD as an ArcView Shapefile or ArcGIS personal geodatabase . It should
be noted that surveyors and engineers usually utilize a computer aided drafting or CAD
product . The optimal means of transferring data from or to a CAD system is to utilize the
Digital Exchange Format or DXF .
&O' Coordinate Systems and Datums
Coordinate Systems
GIS layer spatial information is stored in a coordinate system , defined by the projection of the
map . The coordinate system of the digital map is important . If digital data are obtained
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
and the coordinate system is unknown , then the user may or may not be able to convert the
data to the correct units. It is best to inquire about the coordinate system before receiving
data .
ArcGIS software includes tools to convert between coordinate systems . Because coordinate
conversion can be cumbersome and time consuming , requesting or providing all map
projection information with exchange files is crucial . This information should be provided as a
standard in all metodata files that accompany Indian River County data , or are requested
from outside sources ( see Metadato section below) . The existing standard utilized by Indian
River County is NAD 83 , Florida East, U .S . Feet ( this is the same as the recommended
coordinate system presented below; see " Recommended Coordinate for Indian River
County" below) .
Datums
Another consideration along with the coordinate system is datum . There are two horizontal
datums used almost exclusively in North America . These are the North American Datum of
1927 ( NAD27) and the North American Datum of 1983 ( NAD83) . It is recommended that
cadastral maps in Florida be based upon state plane coordinates adjusted to the 1983
horizontal datum . Other projections and coordinate systems may be used to satisfy special
requirements .
The North American Datum of 1927 uses the Clarke spheroid of 1866 to represent the shape
of the Earth . The origin of this datum is a point on the Earth referred to as Meades Ranch in
Kansas . Many NAD27 control points were calculated from observations taken in the 1800s .
" These calculations were done manually and in sections over many years . As a result of this
process , errors varied from station to station .
Many technological advances in surveying and geodesy since the establishment of NAD27 -
electronic theodolites, GPS satellites , Very Long Baseline Interferometry , and Doppler systems
- revealed weaknesses in the existing network of control points . Differences have become
particularly noticeable when linking existing control with newly established surveys . The
establishment of a new datum allowed for a single datum to cover consistently North
America and surrounding areas .
The North American Datum of 1983 is based on both Earth and satellite observations , using
the GRS80 spheroid . The origin for this datum is the Earth ' s center of mass . This affects the
surface location of all latitude-longitude values enough to cause locations of previous
control points in North America to shift , sometimes as much as 500 feet. A ten-year multi-
national effort tied together a network of control points for the United States , Canada ,
Mexico, Greenland , Central America , and the Caribbean .
NAD27 and NAD83 should not be used in conjunction with one another. If any NAD27
derived data exists then convert it to NAD83 . Tools within GIS software make this a relatively
easy process . Indian River County does not currently have a standard .
Technology Tip - If two GIS layers used in conjunction with each other are
consistently offset by approximately 8- 10 feet, it is probable that there is a
" datum mismatch . It is likely that one layer is utilizing NAD27 datum and the
other NAD83 datum . The NAD27 layer should be converted to NAD83 .
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
* Projections
A map projection is used to portray all or part of the round Earth on a flat surface . This
cannot be done without some distortion . Every projection has its own set of advantages and
disadvantages . There is no "best" projection . GIS users must select the projection best suited
` to specific organization (or peojecf) needs, reducing distortion of the most important
features .
Map projections can be grouped together in two basic ways ; and a third characteristic ,
although if divides different way of using the same projection , is sometimes considered
important enough that different versions of the same projection varying only in this
characteristic are given different names .
The first characteristic is aspect. This identifies the basic layout of the projection . The most
important projections are either cylindrical , conic , or azimuthal . A flat piece of paper can ,
without stretching , be bent into a cone or a cylinder, and in this way, it can touch a globe
along an extended line : if left flat, it only touches the globe at a point .
The basic mathematics of obtaining several important properties of maps is different in these
aspects .
Projections are also classified in terms of their properties . Specifically , on the basis of two very
important properties : whether they are conformal , or equal-area . A conformal projection
maintains the shape of small regions, so angles at any point are correct, although sizes will
change . An equal-area projection , on the other hand, maintains size of the expense of
shape . Maintaining both size and shape , of course , requires a globe .
In general , and this is true for the projections in the three basic aspects of cylindrical , conic ,
and azimuthal , scale going away from the center of a map increases for a conformal
projection , and decreases for an equal-area projection . Most projections that are neither
conformal nor equal area have a scale behavior that is somewhere in between . However,
two very important azimuthal projections lie outside this range : the gnomonic projection ,
which can be used to find the great circle path between two places, and whose scale
expands more quickly than that of a conformal projection , and the orthographic projection ,
which looks like a picture of a globe , whose scale shrinks more quickly than that of an equal-
area projection .
Finally, there is the case of a projection . In essence , the lines of latitude and longitude
(graticules ) on the globe can be moved .
Thus by shifting a graticule on the globe , one can draw a map of a shifted world : that is ,
although the usual rules for drawing a projection place the lines of latitude and longitude on
it in a given way, one can shift the world under the projection 's graticule , and treat the
original graticule of the world like the coastlines and borders on the globe, as simply things to
be drawn where they happen to be .
There is the conventional (or, in the case of an azimuthal projection , polar) case , where the
projection is drawn in the normal and easiest fashion . There is the transverse ( or, in the case
' of an azimuthal projection , equatorial ) case , in which the globe has been shifted by 90
degrees before the map is drawn , and there is the oblique case where the globe is shifted
by a lesser amount .
' 6-S
GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
�
�i
✓3:� Fc?r x tom, ." �f -r i
'14
"Conventional " "Oblique "
Figure 6- 1 : Example of the Mercator Projection in two different cases: the projection on the right shows
the conventional case, whereas the projection on the right shows the oblique case.
The matrices below provide a brief overview of common projections and their properties
and intended uses .
Figure 6-2: Summary of Projection Properties
ue
Projection Type Conformal a ea Equidistant direction
Perspective
Globe Sphere Yes Yes Yes Yes
Mercator Cylindrical Yes Partly
Transverse Mercator Cylindrical Yes
Oblique Mercator Cylindrical Yes
y Space Oblique Mercator Cylindrical Yes
Miller Cylindrical Cylindrical
Pseudo-
(Robinson
cylindrical
.Sinusoidal Equal Pseudo- Yes Partly
,Area cylindrical
Orthographic Azimuthal Partly Yes
" Stereographic Azimuthal Yes Partly Yes
Gnomonic Azimuthal Partly Yes
Azimuthal Equalidistant Azimuthal I Partly Partly
^ Lambert Azimuthal Equal Azimuthal Yes Partly
Area
Albers Equal Area Conic Conic Yes
Lambert Conformal Conic Conic Yes Partly
El
.Equidistant Conic Conic Partly
Polyonic Conic Partly
Biplolar Oblique Conic Conic Yes
Conformal
y 6-6
GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Figure 6-3: Summary of Areas Suitable of Mapping with Projections
Projection Type World Hemisphere Continent/ Region/ Medium Large
Ocean sea scale scale
Globe Sphere Yes
�Mercator Cylindrical Partly Yes
'Transverse Mercator Cylindrical Yes Yes Yes Yes
- Oblique Mercator Cylindrical Yes Yes Yes Yes
Space Oblique Mercator Cylindrical Yes
Miller Cylindrical Cylindrical Yes
Robinson Pseudo- Yes
cylindrical
Sinusoidal Equal Pseudo- Yes Yes
Area cylindrical
Orthographic Azimuthal Partly
Stereographic Azimuthal Yes Yes Yes Yes Yes
Gnomonic Azimuthal Partly
Azimuthal Equalidistant Azimuthal Partly Yes Yes Yes Partly
', Lambert Azimuthal Equal Azimuthal Yes Yes Yes
Area
(Albers Equal Area Conic Conic Yes Yes Yes
Lambert Conformal Conic Conic Yes Yes Yes Yes
Equidistant Conic Conic Yes Yes
Polyonic Conic Partly Partly
Biplolar Oblique Conic Yes
ConicConformal
Figure 6-4: Summary of Projection General Use
Projection Topographic Geological Thematic
j Type Maps Maps Maps Presentations Navigation
Globe Sphere Yes Yes
^' Mercator Cylindrical Yes Yes Yes
Transverse Mercator Cylindrical Yes Yes
Oblique Mercator Cylindrical Yes
x Space Oblique Cylindrical Yes
Mercator
Miller Cylindrical Cylindrical Yes
Robinson Pseudo- Yes Yes
cylindrical
Sinusoidal Equal Pseudo-
Area cylindrical Yes
Orthographic Azimuthal
Stereographic Azimuthal Yes Yes Yes
Gnomonic Azimuthal Yes Yes
Azimuthal Azimuthal Yes
Equalidistant
Lambert Azimuthal Azimuthal Yes Yes
Equal Area
Albers Equal Area Conic Yes Yes
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Projection Type Topographic Geological Thematic Presentations Navigation
Maps Maps Maps
Conic
Lambert Conformal Conic Yes Yes Yes Yes
Conic
Equidistant Conic Conic
Polyonic Conic Yes
Biplolar Oblique Conic Yes
Conic Conformal
*Matrices courtesy of U.S. Geological Survey
Coordinate Conversion
A GIS layer ' s spatial information is stored in a coordinate system , defined by the projection of
the map . The coordinate system of the digital map is important . If digital data are obtained
without a specified coordinate system , it may not be readily possible to determine the
projection .
Various map projection and coordinate conversion tools are available in the ESRI product
suite, as well as other commercial and governmental applications ( Blue Marble, Corpscon ,
etc . ) . Most of the routine coordinate conversions can be performed in ESRI software, yet the
following software is also available forother custom and batch coordinate processing as well
as for conversion of other data formats that may be useful .
Blue Marble Geographics
http : //www. bluemarblegeo . com /
— The Geographic Calculator converts individual coordinates,
point databases, and map files from virtually any coordinate
*�► system , datum , and map projection to any other. Users can
l - transform between coordinate systems , calculate the
distance and azimuth between coordinates, and calculate
coordinates at a known distance and azimuth from known
moi] coordinates . The Geographic Calculator also computes grid
convergence , point scale factor, datum shifts, and grid shifts .
The Geographic Calculator is professionally documented and
supported .
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
U.S. Army Engineer Topographic Engineering Center CORPSCON
http : //crunch . tec .army . mil/softwore / cor[pscon /corr)scon . htmI
Corpscon is a MS-Windows-based program
which allows the user to convert
Lo WF,"a o„ Fa,M sedO$3 Uam, Hao coordinates between Geographic, State
input Format
.. XurixnntaL Geographic Coordinates. Nall ii Plane and Universal Transverse Mercator
Vertical: NGVO 29. U, survey Feet ( UTM ) systems on the North American
Ontput on . Datum of 1927 ( NAD 27 ) , the North
Nonzond:onrol: Stam Mane. Na 83, Virginia XorIM1 0501, Metas
Vertical: GN990, Meters American Datum of 1983 ( NAD 83 ) and
Send Dam
High Accuracy Reference Networks
Output Window ON
Output Fit: OFF ( HARNs ) . Corpscon uses the National
Ai�b=,`'i` OFF Geodetic Survey ( NGS ) program Nadcon
= to convert between NAD 27, NAD 83 and
HARNs .
Recommended Coordinate System for Indian River County
It is recommended that the County to utilize the Florida State Plane Coordinate System , Fast,
based in the North American Datum of 1983 with adjustments to the High Precision Geodetic
Network ( NAD83/ HPGN ) .
Zone Florida East
~ Coordinate System State Plane
Datum NAD83
Projection I Transverse Mercator
n Units U.S. Feet
Scale 0. 99994 11764705882
Central Meridian -81 . 0
Origin ( Latitude) 24.333333333333333
False Easting ) m ) 656166. 6666666665 1
False Northing (m ) 0
Figure 6-5: Recommended Coordinate System
for Indian River County
KtTransfer Media and Backup
Transfer Media
One of the greatest challenges in sharing data is the transfer of data from one computer
system to another. One computer may have data that is in a specific format and
coordinate system , yet there may be no common way to transfer the data to other
computers . There are several ways to provide access to data between computers , but few
standards to do so exist . Floppy disks were the traditional method of data transfer for years .
However, the sheer size of data has significantly reduced the usefulness of diskettes . Given
that an average GIS data file can require up to thirty diskettes or more worth of disk storage ,
determining other alternatives for data transfer is necessary.
High-capacity media , such as tapes , allow for the transfer of much larger data sets .
Unfortunately, there are hundreds of different types of tape drives in the market . Some tape
drives have surfaced as pseudo-standards for UNIX-based GIS . These tape drives are the
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
8mm and the 4mm ( a . k.a . DAT Tape ) . As most GIS systems now operate in a PC
environment, a major challenge has emerged for the standardization of tape use .
Standards do not apply across all systems and configurations .
The table below lists some standard transfer media and their characteristics .
Compact
Media
1
x.044 Unix and PC 700 MB Excellent media for transferring large files.
-yO 4
DVD- R Unix and PC 4. 7 GB-94 GB Comparable to the CD, but has larger storage
capacity. Included on most new PCs.
ZIP Drives
PC 100 MB As standard as comes with a PC . Good for data
transfer with other PCs
Ditto or Jaz PC 100 MB - 2 GB Good for PCs but no standards exist . Data
sharing between machines is difficult
I
Diskette Excellent for small files . Standard drives allow for
Unix and PC 14 MB data sharing between all types of computers.
Not good for big files. Many new computers no
longer include diskette drives .
8mm Unix and PC 2GB - 20GB Is used extensively on Unix computers. Stores
much data . Also, used on PCs but backup
methods vary by drive. Backup speeds are fast.
It is recommended that Indian River County utilize compact discs ( CD- R / CD- RW) and DVD-R
discs as the transfer media of choice . Writeable CDs and DVDs should be utilized for data
sharing and distribution , depending on which type of media can be utilized by those
receiving the data . Using these two types of media will allow for flexibility when sharing data
with or receiving data from other entities . Writeable CDs can be used for data sharing
between all types of computers , as almost all computers today come standard with a CD-
ROM drive . Therefore, any data written with the writeable CD- ROM drive can be used on
any PC with a CD-ROM drive . While DVDs are not used as commonly as CDs , DVDs offer
greater storage capacity and the ability to transfer large data sets that would usually need
to be divided into multiple CDs . DVD-R use is increasing , and it is expected that this type of
media will become as popular as CDs in the future .
A majority of internal data sharing at Indian River County will be done through Indian River
County ' s high-speed network. Data sharing through the network eliminates the need for
sharing via disk or tape .
Sharing Data via the Internet
An excellent way of sharing data is via the Internet . Sharing data through the Internet
precludes the need to use tape drives and tape formats to transfer data . However, there
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
are some limiting factors to this type of data transfer, primarily data transfer speed . Data
transfer speed will be slow when using a modem connection to the Internet.
Transferring large GIS files by modem is not a good idea and may even be impossible . A
» single GIS file could take hours and possibly days , to transfer via a modem . Additionally,
modem connections to the Internet can often be lost during file transfer, requiring the restart
of the file transfer process . Files that would typically take hours to transfer with a modem
take only a few minutes to transfer using a high-speed ( broadband ) connection and file
transfer protocol ( FTP) software . It is recommended that Indian River County ' s FTP site
include a public access section for transferring files with the public, consultants, etc .
Copying 'calaveras_co .zip'
To 'C: �Scratch' !'
-- g :.._Cancel.....;
I 1
36 Minutes Remainin
Figure 6-6: Using the Internet for file transfer can be slow
when attempting to transfer large files.
StData Creation and Maintenance
This section provides two recommended Standard Operating Procedures for Indian River
" County, one for maintaining or updating existing data resources , and one for adding new
data resources to the GIS .
» Roles
This section describes the roles and responsibilities of Requesters , the GIS Director, subject
matter experts (SMEs) , and department supervisors with respect to modifying existing or
adding new resources to the GIS .
Requester
A Requester is a person who wants to modify or add a data resource to the GIS . If the data
resource meets minimum requirements , or if the GIS Director authorizes the submittal , the
requestor must complete the appropriate Request Form .
- GIS Director
The GIS Director is responsible for tracking all resource submittals and providing some initial
quality assurance ( QA ) of the data . The GIS Director is in charge of layers that are used by
all departments . The GIS Lead or Subject Matter Expert (SME) is a person who accepts or is
assigned the responsibility of maintaining GIS data in his or her own department. This person
should have sufficient technical expertise to be assigned with this responsibility. Regardless
of who makes a request, the GIS Director has the authority to refuse requests from a
Requester; the GIS Director also acts as the point of contact for requesters and SMEs for
particular submittals . He or she provides guidance in converting file formats , data cleanup,
and compatibility of proposed resources with existing GIS resources . If a resource is
accepted , the GIS Director will install the resource and make changes to any relevant
documentation .
_
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GIS Needs Assessment and Implementation Plan Chapter 6 — Data Standards and Transfer
Subject Matter Experts
Subject Matter Experts (Also Referred to as Departmental GIS Lead) are responsible for
particular data resources . If a proposed resource is similar to , or has a potential impact on ,
an existing resource, the SME for the existing resource needs to review the submittal . The SME
will make or oversee the changes to the data resource when updates are required . The SME
should provide guidance to the GIS Director as to whether or not the proposed resource
conflicts with , enhances, or will result in changes to an existing resource or resources . The SME
is further responsible for updates to a modified data resource ' s metadata file .
Supervisor
The Supervisor for each SME is responsible for ensuring that the SME is qualified and has
enough time as well as resources ( i .e . , training , computer system , or other resources) to
perform the duties required .
Data Maintenance Procedure for Existing Data
Three types of spatial data layers will be utilized by Indian River County:
1 . Layers used and maintained by only one department
2 . Layers maintained by one department , but used by many
3 . Layers updated by the GIS Director
The following guidelines do not apply to layers that are used and maintained by only one
department .
Any GIS user may request changes or updates to an existing data resource . The request is
made to their SME using the Data Maintenance Request form (see Example A below) . The
SME will review the request and approve it, if deemed appropriate , and forward the request
to the GIS Director. The GIS Director will review the request to ensure that the layer is in
compliance , and if it is, the request will be sent back to the SME .
Because specific departments continually maintain some layers , it is not feasible to require
that each change be approved through the full chain of command . In such cases it is
recommended that blanket annual approval of these updates should be granted . The GIS
Director should create an application that will audit, test, and validate these data layers to
check for consistency and validity . Semi-annual testing of these data layers should be
implemented .
The SME is responsible for completing all of the corrections and/or updates , including
updates to the metadata file . Corrections should be made to copies of the data resource
files as required . The GIS Director may assist the SME in this effort by providing technical
support, staff resources , CAD to GIS conversion , and other tasks as required : however, it is
ultimately the SME ' s responsibility to ensure that the new data is correct .
Once a request is approved and new files are finalized , the SME will return the completed
v request form to the GIS Director along with the updated data . Data files may be on
separate media ( CD , floppy, etc .) , or a corresponding network location ( s ) may be indicated
on the request form . The intended final disposition of the original data resource files should
also be indicated on the form .
The GIS Director will be responsible for validating new data . This responsibility includes :
• Verifying that topology and attribute structure of the new data matches that of the
old
• Verifying that attribute record data are intact
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
• Verifying that all links and joins used by the GIS system are still functional with the new
data
• Verifying that the new data and metadata are in agreement
• Verifying that the new dataset conforms to Indian River County data standards
Any discrepancies found must be resolved with the SME prior to the implementation of the
updated data resource within the GIS .
Once the GIS Director and the SME have approved the updated data , the GIS Director will
move the old data resource files (including the old metadata file ) to an archive directory for
temporary storage , and copy the updated files to the network GIS server. The GIS Director
will be responsible for updating any other relevant GIS documents , such as File Lists, Layer
Lists, and Metadata Indices .
Each department will need a SME regardless of whether he or she will update data . For
example, the Sheriff ' s Department would need an SME to inform the GIS Director that data
needs to be updated , but the GIS Director would be responsible for the updates .
* New Data Resource Procedure
This Standard Operating Procedure relates to the addition of new data resources to the GIS .
It does not address changes to existing GIS data . To update or amend any existing GIS data ,
contact the GIS Director. Example A of this section contains a submittal form that provides
some guidelines on data requirements .
Criteria for Acceptance or Rejection of New Data
Indian River County is interested in seeing its GIS grow and become more sophisticated . This
requires that new data resources be added to the system so that a wider group of users will
use the GIS productively. To achieve this objective , the acceptance process has not been
made overly rigid . The GIS Director is authorized to accept or reject a submittal based on
some basic criteria , with additional discretionary flexibility .
The GIS Director may accept new resources only if all of the following criteria are met:
• Resource is ready " as-is " and requires no updates or modifications (with the
exception of CAD and Arclnfo files, which may be converted to SHP files , and
eventually geodatabase layers)
• It conforms to Indian River County GIS Data Standards
• The SME is already assigned and has signed off an the submittal
• Future update and maintenance requirements are minimal or the requestor accepts
responsibility for the needed updates and/ or maintenance
The GIS Director may reject new resources if:
• No one needs access to the data
• Significant maintenance of the data will be required and no one can assume
responsibility for this task
Procedure
The procedure for submitting new resources for inclusion in the GIS is outlined in Example B
below. The requestor is encouraged to consult with the GIS Director if one or more
requirements are not met . The GIS Director may grant an exception , allowing the process to
continue . This exception does not imply that the resource has been accepted ; the resource
must still go through the normal review process .
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
After the requester determines that the resource is eligible for consideration , the submittal
form entitled " Request to Add New GIS Data Resource " must be completed (see Example B
below) . The requester should have the request reviewed and approved by his or her
supervisor. If the requestor is not the designated SME , the SME ' s agreement needs to
obtained and authorized by his or her supervisor.
The aforementioned process needs to be complete before the request package is
submitted to the GIS Director. The GIS Director should receive the following three items :
• A completed " Request to Add New GIS Data Resource " document with authorizing
signatures
• A copy of the proposed data resource on transfer media , or a copy transferred
electronically via email or ftp
• A hard-copy printout of the electronic file ( if practical )
The GIS Director will perform an initial review. If the submittal is not complete, it will be sent
back to the requestor with the deficiencies identified . Otherwise, the SMEs for affected
resources must be consulted to determine if the proposed resource duplicates or overlaps
existing resources .
If all SMEs and the GIS Director approve the submittal , the GIS Director will assign a staff
member to place the new data resource on the GIS server and update any affected
documentation .
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Example A: GIS Data Maintenance Request Form
Request to Update Existing GIS Data Resource
SUMMARY INFORMATION
- Submitted by: Date :
Department : Phone :
Indian River County Name of Data Set:
Description :
Update to Data Type : ❑ Vector ❑ Raster
( Check all that apply) ❑Tabular ❑ Documents
❑ Other
Subject Matter Expert (SME) :
Describe the corrections , updates , or additions to the data resource you are requesting :
- List dor attach ) any additional documents that are related to this update :
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
The SME shown above has examined this request to update an existing GIS data resource ,
and has determined that the updates or corrections are needed . The SME has acquired
copies of the data resource files , made the appropriate changes or additions , and has duly
modified the associated metadata files. These corrected files are provided to the GIS
Director with authorization to replace the existing data resource files on the network GIS
server with the updated data resource files attached or referenced in this form .
(SME Signature ) Date
SME Use:
Provide the network location of the updated data resource files related to this update
request:
Final disposition of existing data resource files ❑ Archive ❑ Delete
The GIS Director for Indian River County GIS has received all required files and approvals from
the SME regarding this data resource maintenance request , and implemented the updated
files on the network GIS server. All other affected GIS files have been updated to reflect the
changes in this data resource .
( GIS Director Signature ) Date
n
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Example B: New Data Resource Form
Request to Add GIS Data Resource
1 . SUMMARY INFORMATION (all information in Section I is required)
Submitted by: Date :
Department : Phone :
Title of Data Set:
Description :
Type : ❑ Vector ❑ Raster
' ❑Tabular ❑ Document
❑ Other
( Complete checklist for the appropriate type)
Frequency ❑ Never ❑ Annually ❑ Quarterly ❑ Monthly ❑ Weekly ❑ Daily
of Update :
Subject Matter Expert (SME) :
The SME shown above agrees to be responsible for updating , creating and maintaining this
layer at the frequency shown above . The SME ' s supervisor, by signing below, acknowledges
that SME is authorized to perform this function as collateral duty ( unless otherwise
designated ) .
(SME Signature )
(SME Supervisor ' s Signature)
Who are the potential users of this layer ( list by name , department, and/or position ) ?
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Why do you think this resource should be added to the GIS ?
Does this data replace (yes/no) or duplicate (yes / no ) any data set currently in the GIS ? If
f answer to either is " yes, " explain here :
2. SPATIAL DATA ATTRIBUTES (all information in Section 2 is required)
These questions should be answered for spatial data only ( i .e . , CAD , GIS , orthorectified
photos) .
How are the data georeferenced ? ❑ Projected (X , Y) ❑ Geographic ( Lat/ Long ) ❑ N / A
If Projected :
What projection system was used ?
State Plane ❑ HIPS Zone :
Other (Specify) ❑
What datum was used ?
NAD83 ❑
NAD27 ❑
Other ( Specify) ❑
What units are distances in ?
US Feet ❑
Int ' I Feet ❑
Meters ❑
Other (Specify) ❑
If Geographic ,
What datum was used ?
NAD83 ❑
NAD27 ❑
Other ( Specify) ❑
What units are distances in ?
Dec . Deg . ❑
Deg . Min Sec . ❑
Other (Specify) ❑
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Does the data have a vertical component? ❑ Yes ❑ No
If Yes :
What datum was used ?
NGVD29 ❑
NAVD88 ❑
ELLIPSOID ❑ Spheroid Used :
Other (Specify) ❑
" What units are the elevations in ?
US Feet ❑
Int ' I Feet ❑
Meters ❑
Other (Specify) ❑
3. DATA FORMAT
Answer as many of the following questions as possible for all data types . Questions with an
asterisk ( - ) must be answered .
What software was used to generate this data set (include version or release number) ?
Vector Data
GIs
ESRI Geodatabose ❑
ESRI Shapefile ❑
Arclnfo Coverage ❑
Other ❑ specify
Include attribute specifications for GIS spatial data
Raster Data
Type
Scanned Photos ❑
Scanned Documents ❑
Satellite Imagery ❑
Data Surface (single) ❑
v Data Surface ( stack) ❑
Other ❑ specify
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Format
TIF/TFW ❑
GeoTIF (TIF 6 ) ❑
BIL, BIP , BIF ( raw) ❑
GIF , JPG , BMP ❑
MR . SID ❑
Arclnfo GRID ❑
Other ❑ specify
Is the data compressed ? ONO DYES ( Algorithm used : )
How many bands ? ❑ 1 ( binary or gray) ❑ 3 ( color) ❑ >3 (satellite or stack )
If >3, specify the bands and their content:
Radiometric Resolution : ❑ 6-bit ❑ 8-bit ❑ Other
Tabular Data
Spreadsheets
Excel ❑
Lotus 1 -2-3 ❑
QuattroPro ❑
Other ❑
w Databases
AS400 ❑
Access ❑
Paradox ❑
Oracle ❑
SQL Server ❑
Other ❑
Text
Delimited ❑ Specify Delimiter:
Fixed Length ❑ ( Attach file specification )
Document Data
Format
Word Pro ❑
Ami Pro ❑
Word ❑
WordPerfect ❑
PDL ❑
HTML ❑
Other ❑
6- 15
GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
4. DATA QUALITY
Answer as many of the following questions as possible for all data types . Questions with an
asterisk ( * ) must be answered .
Why were these data collected ( i .e . , for what purpose ) ?
* How were these data collected ?
*When were these data collected ?
Have these data been updated since their original creation ? If so, how often and what was
the nature of the update ?
When was the last update and what percentage of the data were affected (estimate if
unknown and indicate if is approximate) ?
( GIS Director Signature ) Date
6- 16
GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Data Indexing Strategies
Metadata
Metadata is simply "data about data ." Metadata gives detailed information about all
aspects of geospatial data .
Metadata can give background information about:
• Source
• History
• Content
• Quality
• Condition
• Availability
Processing
• Technical Details
Although metadata is usually developed and obtained in a digital format , metadata can be
posted as part of a paper map , primarily as part of the map legend . In this form , metadata is
readily apparent and easily transferred between map producers and map users . This data is
usually fairly simple and short, maybe just a few sentences , conveying the generalities about
the data . For example : "This flood plain map was created with data obtained from USGS ,
,. was created in 1998, is in California State Plane ( U .S . Feet) and the datum is NAD83. "
Digital data requires more effort and detail in development and maintenance on the part of
data producers . However, this data is valuable in two ways :
1 . The primary creator of the data benefits because metadata maintains the value of
the data set, enabling its continued use over time
2 . Metadata helps other users to find and use geo-spatial data , especially if the data
are stored in a GIS clearinghouse or general repository
Various metadata standards have been developed over the years . One standard in wide
use and acceptance is the Federal Geographic Data Committee ( FDGC ) " Content
Standards for Digital Geospatial Metadata " in use by all Federal data producing agencies .
The comprehensive metadata example provided below (see Example C ) complies with
Federal guidelines . However, there are minimum content standards that greatly simplify this
standard , and alternatives are also presented .
ArcCataloq
It is strongly recommended that the GIS Director implement a data indexing system to
logically organize and share data . For immediate expanded use of GIS throughout the
organization , metadata , storage location , and maintenance processes should be
documented so all potential users of the GIS data will have a better understanding of the
dataset they are using .
Integrating metadata into a GIS in a way that is readily accessible to users of all experience
} levels has proven to be a major challenge . Additionally, many government and private
agencies have found the metadata system to be a bit cumbersome ; consequently, these
entities have not proactively updated or created this base information which is so crucial for
end-users . With ESRI ' s latest release of ArcGIS 9 , GIS data indexing has greatly improved and
as a result has allowed GIS users charged with managing data to update and edit
6- 17
GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
metadata easily. ArcCatalog provides an intuitive and effective approach to previewing
data , metadata , and managing data locations .
NONE=
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Figure 6- 7: Arc Catalog Interface
Through the use of ArcCafalog , users can easily view directory structure , preview actual
geodatabases, coverages , shapefiles , CADD files , and orthophotography files , as well as
other file types . Previously created Metadata is automatically linked to these files , and is
referenced with a click of the Metadata button . Metadata that has not been previously
created can either be imported or created in one of many formats chosen by the user .
These types will be explained in detail in this section .
Data Access in ArcCataloa
The Catalog is where users can assemble connections to data sources . When a connection
is selected, the user accesses the data to which the file is linked . The connection might
access a folder on a local disk, a database on the network, or an ArcIMS Internet server.
Together, the connections create a catalog of geographic data sources . Once the
desirable data has been found , the preview and metadata tabs can be clicked to show a
view of the data , as well as the metadata describing the file .
Creating and accessing geodatabases
To manage a spatial database, users can create a personal geodafabase, which stores
data in Microsoft Access format. For an enterprise geodafabase, ArcSDE lets many people
in an organization update data stored in a centrally located RDBMS .
Data Organization in ArcCatapg
ArcCatolog manages maps and geographic data in a similar style as Windows Explorer. All
- standard Windows shortcuts and drag /drop techniques for copying , moving , renaming , or
deleting items work in ArcCafalog . These features make if easy to organize not only data
sources on disk ( such as coverages and shapefiles) , but data stored in databases as well .
The user can copy or move database connections and coordinate systems from those
folders in the Catalog to any other folder in any location ; for example , SDE geodafabase
connections and custom coordinate systems can be placed in a shared folder on the
network where everyone in the organization can access them .
6- 18
GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Note:
" When a user copies, renames , or deletes data sources with ArcCatalog , auxiliary files
and other data sources that are linked to the datasets are also copied , renamed, or
deleted . For example, metadata , projection , and index files all accompany a file-
based data source. A file-based raster's auxiliary files will accompany the raster. When
copying a feature class from one personal geodatabase to another, any feature
classes and tables that are linked to it through relationship classes will also be copied to
the destination geodatabase .
How metadata is stored
Metadata created with ArcCatalog is stored as XML, either in a file alongside the item , or
within its geodatabase. XML is a structured markup language similar to hypertext markup
language ( HTML) . HTML defines both the data and how it is presented . XML, on the other
hand , lets the user define data using tags that add context and meaning .
XML is an emerging industry standard that is being used to transfer data across the Internet.
For example , it is often used in e-commerce transactions . Many different applications can
be used to view or edit metadata XML files .
Metadata for folders and aeodatabases
Another new option of ArcCatalog is that the user can document the contents of a folder or
geodatabase . This metadata is created in the some way as shapefile , coverage, or
geodafabase layer metadata . The benefit of this type of documentation is to track
important information such as date of creation , description of file contents and their
purpose , and the status of completion . This type of information is helpful to other users when
they are browsing for data .
6- 19
GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
J
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6-20
GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
y About importing and exporting metadata
Metadata that exists in earlier ESRI formats can be easily imported into ArcCatalog . The
formats that are easily importable are :
• Text
• XML
• SGML - Standard Generalized Markup Language (SGML) format defined by the
FGDC 's metadata parser utility
ArcCatalog uses the FGDC ' s metadata parser utility itself to import and export metadata in
its supported formats . The XML format can be used to import metadata that was created
with ArcCatalog . The importers provided with ArcCatalog will overwrite all of an item 's
existing metadata .
Note : if Enable automatic update of metadata is unchecked , ArcCatalog will not overwrite
any existing values .
FGDC Metadata Workbook
The FGDC Metadata Workbook , Version 2 .0 is in electronic form ( Adobe PDF - book marked
enabled ) . The workbook is free of charge and is easily down loadable (size 130 pages , 1 Mb) .
The workbook complies with the latest version of the FGDC Content Standard for Digital
Geo-spatial Metadata ( CSDGM ) , FGDC-STD-001 - 1998 and contends both textual and color
graphical information about the FGDC CSDGM including background information , how to
read and use the Standard , a color graphical and textual representation of the content
information of the Standard , a description of Profiles and User Defined Metadata Extensions ,
and some metadata examples . The workbook is free to download and can be distributed
among organizations . To access this workbook, visit the following link:
htto : //www. fgdc .gov/ metadata / meta workbook html
Why Metadata ?
The major uses of metadata are :
• Help organize and maintain an organization's internal investment in spatial data ,
• Provide information about an organization 's data holdings to data catalogues ,
clearinghouses, and brokerages
• To provide information to process and interpret data received through a transfer from
an external source .
Y The Standard
What do internal and external organizations need to know about Indian River County ' s
datasets ? The standard provides a common set of terminology and definitions for the
documentation of geo-spatial data , including data elements for the following topics :
• Identification Information : basic information about the data set. Examples include
title, geographic area covered , currentness , and rules for acquiring or using the data .
• Data Qualify Information : an assessment of the quality of the data set . Examples
include positional and attribute accuracy, completeness , consistency, sources of
information , and methods used to produce the data . Recommendations on
information to be reported and tasks to be performed are in the Spatial Data Transfer
$ Standard ( Federal Information Processing Standard 173 - 1992) .
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
• Spatial Data Organization Information: the mechanism used to represent spatial
information in the data set. Examples include the method used to represent spatial
positions directly ( such as raster or vector) and indirectly (such as street addresses or
County codes) and the number of spatial objects in the data set.
• Spatial Reference Information: description of the reference frame for, and means of
encoding , coordinates in the data set . Examples include the name of and
parameters for map projections or grid coordinate systems , horizontal and vertical
datums , and the coordinate system resolution .
• Entity and Attribute Information: information about the content of the data set,
including the entity types and their attributes and the domains from which attribute
values may be assigned . Examples include the names and definitions of features,
attributes, and attribute values .
• Distribution Information: information about obtaining the data set. Examples include
a contact for the distributor, available formats, information about how to obtain data
sets online or on physical media (such as cartridge tape or CD- ROM ) , and fees for
the data .
• Metadata Reference Information: information on the currentness of the metadata
information and the responsible party.
The standard has sections that specify contact information for organizations or individuals
that developed or distribute the data set, temporal information for time periods covered by
the data set , and citation information for the data set and information sources from which
the data were derived . The standard does not specify how this information is organized in a
computer system or in a data transfer, nor the means by which this information is transmitted
or communicated to the user. At this point in time , these formats are optional .
Additional Information
The standard and other metadata materials, along with the implementation guidelines for
the clearinghouse , are available from the FGDC at the above address or from the FGDC
server connected to the Internet via :
Anonymous FTP Metadata - www.fgdc .,qov under the subdirectory /pub/metadata
Clearinghouse - www .tgdc . gov under the subdirectory / pub/clearinghouse
The README files in the subdirectories give detailed information about the available files .
FGDC Web Server http ://www. fgdc . gov/
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Example A : FGDC - Compliant Mefadata
Identification-Information :
Citation :
Citation Information :
Originator:
U .S . Department of Commerce
Bureau of the Census
Geography Division
Publication Date : 2001
Title: TIGER /Line Files , Redistricting Census 2000
Edition : Redistricting Census 2000
Series Information :
Series-Name : TIGER/ Line Files
Issue_ldentification : Version (MMYY ) represents the month and year file created
Publication Information :
' Publication_Place : Washington , DC
Publisher:
U .S . Department of Commerce
Bureau of the Census
Geography Division
Description :
Abstract:
TIGER , TIGER /Line , and Census TIGER are registered trademarks of the Bureau
of the Census . The Redistricting Census 2000 TIGER/ Line files are an extract
of selected geographic and cartographic information from the Census TIGER
' data base . The geographic coverage for a single TIGER/ Line file is a county
or statistical equivalent entity, with the coverage area based on January 1 ,
2000 legal boundaries . A complete set of Redistricting Census 2000 TIGER / Line
files includes all counties and statistically equivalent entities in the United
States and Puerto Rico . The Redistricting Census 2000 TIGER /Line files will
not include files for the Island Areas . The Census TIGER data base represents
a seamless national file with no overlaps or gaps between parts . However, each
county- based TIGER/ Line file is designed to stand alone as an independent data
set or the files can be combined to cover the whole Nation . The Redistricting
Census 2000 TIGER/ Line files consist of line segments representing physical
" features and governmental and statistical boundaries . The Redistricting Census
2000 TIGER /Line files do NOT contain the ZIP Code Tabulation Areas ( ZCTAs ) and
the address ranges are of approximately the same vintage as those appearing in
the 1999 TIGER/ Line files . That is, the Census Bureau is producing the
Redistricting Census 2000 TIGER / Line files in advance of the computer processing
that will ensure that the address ranges in the TIGER/ Line files agree with the
final Master Address File ( MAF ) used for tabulating Census 2000 .
Purpose :
In order for others to use the information in the Census TIGER data base in a
geographic information system ( GIS ) or for other geographic applications , the
Census Bureau releases to the public extracts of the data base in the form of
TIGER/ Line files . Various versions of the TIGER/ Line files have been released ;
previous versions include the 1990 Census TIGER /Line files , the 1992 TIGER /Line
files, the 1994 TIGER / Line files , the 1995 TIGER / Line files, the 1997 TIGER/ Line
files , the 1998 TIGER / Line files , and the 1999 TIGER/Line files . The Redistricting
A 6-23
GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Census 2000 TIGER/ Line files were originally produced to support the Census 2000
Redistricting Data Program .
Supplemental-Information :
To find out more about TIGER/Line files and other Census TIGER
data base derived data sets visit http ://www . census .gov/geo /www/tiger.
Time Period of Content:
Time-Period-Information :
w
Single-Date/Time :
Calendar-Date : 2000
Curren tness_R of ere nce: 2000
Status :
Progress : Complete
Main lenance_and_U pdate_Frequency:
TIGER/ Line files are extracted from the Census TIGER data base when needed for
geographic programs required to support the census and survey programs of the
Census Bureau . No changes or updates will be made to the Redistricting Census
2000 TIGER/Line files .
Spatial-Domain :
Bounding-Coordinates :
West-Bounding-Coordinate : + 131 .000000
East-Bounding-Coordinate : -64 .000000
North-Bounding-Coordinate : + 72 .000000
South-Bounding_Coordinate : - 15 .000000
Keywords :
Theme :
Theme-Keyword-Thesaurus : None
Theme-Keyword : Line Feature
Theme_Keyword : TIGER/ Line
Theme-Keyword : Topology
Theme-Keyword : TIGER/Line Identification Number (TLID )
Theme-Keyword : Street Segment
Theme-Keyword : Coordinate
Theme-Keyword : Boundary
Place:
Place-Keyword-Thesaurus :
HIPS Publication 6-4
HIPS Publication 55
Place-Keyword : United States
Place-Keyword : Puerto Rico
Place-Keyword : County
-
Access-Constraints : None
Use Constraints :
None . Acknowledgment of the U .S . Bureau of the Census would be appreciated for
products derived from these files . TIGER , TIGER/ Line, and Census TIGER are
registered trademarks of the Bureau of the Census .
Native-Data-Set-Environment:
TIGER/ Line files are created and processed in a VMS environment . The environment
consists of two Alpha Server 8400s clustered together running OpenVMS version
6 .2- 1 H3 used for production operations .
Data_Quality-Information :
Attribute_Accuracy:
Attribute-Accuracy-Report:
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Accurate against Federal information Processing Standards
( FIPS) , HIPS Publication 6-4, and FIPS-55 at the 100% level for the codes and base
names . The remaining attribute information has been examined but has not been fully
tested for accuracy.
Logical-Consistency-Report :
The feature network of lines (as represented by Record Types 1 and 2) is compete
for census purposes . Spatial objects in TIGER/ Line belong to the "Geometry and
Topology" ( GT) class of objects in the "Spatial Data Transfer Standard" (SDTS )
HIPS Publication 173 and are topologically valid . Node/geometry and topology
( GT) -polygon /chain relationships are collected or generated to satisfy topological
edit requirements . These requirements include :
* Complete chains must begin and end at nodes .
` Complete chains must connect to each other at nodes .
* Complete chains do not extend through nodes .
Completeness-Report:
Data completeness of the TIGER / Line files reflects the contents of the Census TIGER
data base at the time the TIGER/ Line files ( Redistricting Census 2000 version ) were
b created .
Position al_Accuracy:
Horizontal-Positional-Accuracy :
Horizontal-Positional-Accuracy-Report:
The information present in these files is provided for the purposes of statistical
analysis and census operations only . Coordinates in the TIGER/ Line files have six
implied decimal places , but the positional accuracy of these coordinates is not as
great as the six decimal places suggest . The positional accuracy varies with the
source materials used , but generally the information is no better than the established
national map Accuracy standards for 1 : 100, 000-scale maps from the U .S . Geological
M Survey ( USGS ) : thus it is NOT suitable for high- precision measurement applications
such as engineering problems , property transfers , or other uses that might require
highly accurate measurements of the earth 's surface . The USGS 1 : 100, 000-scale maps
met national map accuracy standards and use coordinates defined by the North
American Datum , 1983 ,
Lineage :
Source Information :
Source Citation :
Citation Information :
Originator:
U . S . Department of Commerce
Bureau of the Census
Geography Division
Publicafion_Date : Unpublished material
Title : Census TIGER data base
Edition : Redistricting Census 2000
Type-of-Source-Media : On line
Source-Time-Period of Content:
Time-Period-Information :
Single_Dote/Time :
Calendar Date : 2000
Source-Currentness-Reference : Date the file was made available to create TIGER/ Line
File extracts .
Source-Citation-Abbreviation: TIGER
Source Contribution :
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
Selected geographic and cartographic information (line segments) from
the Census TIGER data base.
Process-Step :
Process-Description :
In order for others to use the information in the Census TIGER data base in
a GIS or for other geographic applications, the Census Bureau releases periodic
extracts of selected information from the Census TIGER data base, organized as
topologically consistent networks. Software (TIGER DB routines) written by the
Geography Division allows for efficient access to Census TIGER system data .
TIGER/ Line files are extracted from the Census TIGER data base by county or
y statistical equivalent area .
Source-Used_Citation-Abbreviation : Census TIGER data base
Process Date : 2000
Spatial_Data_Organization_Information :
Indirect-Spatial-Reference :
Federal Information Processing Standards ( FIPS ) and feature names
and addresses .
Spatial-Reference-Information :
Horizontal-Coordinate-System-Definition :
Geographic :
Latitude-Resolution : 0 .000458
Longitude-Resolution : 0.000458
Geographic_Coordinate-Units : Decimal degrees
3) Locations of KGLs
Distribution-Information :
Distributor
Contact_Information :
Contact_Organization-Primary:
Contact-Organization :
U . S . Department of Commerce
Bureau of the Census
Geography Division
Products and Services Staff
Contact Address :
Address-Type : Physical address
Address : 8903 Presidential Parkway , WP I
City: Upper Marlboro
State_or Province : Maryland
Postal Code : 20772
Contact-Voice-Telephone: (301 ) 457- 1128
Contact Address :
Address-Type : Mailing address
Address : Bureau of the Census
City : Washington
State-or-Province: District of Columbia
Postal Code : 20233-7400
Contact-Voice-Telephone : ( 301 ) 457- 1128
Contact-Facsimile_Telephone :
( 301 ) 457-4710
Contact-Electronic _Mail-Address : tiger�census .gov
Resource-Description : Redistricting Census 2000 TIGER/ Line Files
Distribution-Liability:
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
No warranty, expressed or implied is made and no liability is
assumed by the U .S . Government in general or the U .S . Census Bureau in specific as
to the positional or attribute accuracy of the data . The act of distribution shall
not constitute any such warranty and no responsibility is assumed by the U .S .
Government in the use of these files .
Standard-Order-Process :
Digital-Form :
Digital_Transfer_Information :
Format-Name : TGRLN (compressed )
Form at_Version_Number: Redistricting Census 2000
Format-Version-Date : 2000
File_Decompression_Technique : PK-ZIP , version 1 . 93A or higher
Digital_Transfer_Option :
Online-Option :
Computer-Contact-Information :
Network Address :
Network_Resource_Name : www. census . gov/geo/www/ tiger
Fees :
The online copy of the TIGER /Line files may be accessed without charge . See
http: //www . census .gov/geo /www/tiger for information on availability on CD-ROM /DVD
and associated costs for these products .
Ordering-Instructions :
To obtain more information about ordering TIGER/ Line files visit
hffp ://www.census .gov/geo/www/ tiger.
Metadata Reference Information :
Metadata- Date: 2000
Metadata Contact:
Contact Information :
Contact_Organization_Primary:
Contact-Organization :
y U .S . Department of Commerce
Bureau of the Census
Geography Division
Products and Services Staff
Contact Address :
Address-Type : Physical Address
Address : 8903 Presidential Parkway, WP I
City: Upper Marlboro
State-or-Province : Maryland
Postal Code : 20772
Contact-Voice-Telephone : ( 301 ) 457- 1128
Contact-Electronic-Mail-Address : tigeracensus .gov
Metadata-StandardName : FGDC Content Standards for Digital Geospatial Metadata
Metadata-Standard Version : 19940608
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer
I Name 93flood
Metadato date 1998
Feature Polygon
Ori inator Federal Emergency Mana ement Agency
The Q3 Flood Data are derived from the Flood Insurance Rate Maps ( FIRMS) published by
the Federal Emergency Management Agency ( FEMA) . The file is georeferenced to the
Description earth 's surface using the Universal Transverse Mercator ( UTMI projection and a zonal
coordinate system (units in meters . Specifications for the horizontal control of Q3 Flood
Data files are consistent with those required for mapping of a scale of 1 :24000.
Purpose Purpose: The FIRM is the basis for floodplain management, mitigation, and insurance
activities for the National Flood Insurance Program (NFIP) . Insurance applications include
enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act,
which "requires the purchase of flood insurance by property owners who are being assisted
by Federal programs or by Federally supervised, regulated, or insured agencies or institutions
in the acquisition or improvement of land facilities located or to be located in identified
areas having special flood hazards" (Section 2 ( b) � 4) of the 1973 Flood Disaster Protection
Acts . In addition to the identification of Special Flood Hazard Areas (SFHAs) , the risk zones
shown on the FIRMS are the basis for the establishment of premium rates for food insurance
coverage offered through the NFIP. Q3 Flood Data files convey certain key features from
the existing hard copy FIRM. Edge-matching errors, overlaps and deficiencies in coverage,
and similar problems are not corrected during digitizing or post-processing . The Q3 Flood
Data files are intended to provide users with automated flood risk data that may be used to
locate SFHAs . More detailed information may be obtained from the paper FIRM .
film a Period of Content Calendar Date: 1998
Status Progress : Complete
Maintenance and Update Frequency: Irregular
Contact Organization: Federal Emergency Management Agency, Mitigation Directorate
' Contact Address
Address: 500 C Street, S.W .
Point of Contact City: Washington
State or Province: District of Columbia
Postal Code: 20472
Contact voice Telephone: 1 -800-358-9616
Attribute Definitions Fips: County code,
Long: Longitude
Lit: Latitude
State: State code
etc .
03 Flood Data were produced by eithersconning and vectoraing or manually digitizing a
hardcopy version of the graphic materials. The scanning and veciorizarion process
captured the digital data os rosier data that were vectorfzed and attributed on an
interactive editing station. The manual digitizing process used a digitizing fable to capfure
the digital data; attribution was performed either as the data were digitized or on on
Interactive edit station atter the digitizing was completed. The determination of the
production methodology was based on various criteria, including availability of producrion
systems. Four to nine control points per FIRM panel were used for registration during manual
digitizing. A projective transformation was performed on the coordinates used in the data
collection and editing systems to register the dig;toi data to the Universol Transverse
Mercator (UTM) grid coordinates. An ARCINFO coverage of the Q3 Flood Data was
Process Steps generated and used to create the 03-DLG file. The 03 Flood Data were checked for
position and attribute accuracy by comparing plots of the digital data tothe source
graphic and by symbolized display on an interactive computer system. Selected attributes
that could not be visuaily verified were individually queried In addition, an ARCINFO Arc
Macro Language (AivQ software progrom was applied to the dataset to test the attributes
against a master set of valid attributes for the specific data category and o complete set of
valid atinbute combinations. Source graphics were revised to reflect updates effected by
Letters of Map Change (Leiferof Map Revision [LOMRJ, Letter of Map Amendment (LOMAJ) .
These revisions were included in the Q3 Flood Data if they were mappable at the
publication scale of the source graphic. Once final, the ARCiNFO coverage is projected
into a geographic grid system, using decimal degree latitude and longitude coordinates
and then converted into on ARCINFO Ex ort file.
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StMetodata Recommendations
It is recommended that Indian River County adopt the FGDC metadata standard ( basic
version ) . Maintaining this standard will facilitate data sharing between the County and
various other organizations and agencies . Additionally, it may prove valuable for the County
to collaborate on modifying metadata standards in the future with other local governments
to ensure that metadata is homogenous both locally and regionally.
There are a number of third party software applications that make standardization and
production of metadata a much simpler task . ESRI ArcGIS also includes metadata tools ( as
detailed above that are recommended . Regardless of the metadata standard and
production method selected , it should be :
• adopted for Countywide use
• documented for distribution
• readily accessible with any GIS layer
• a " living " document that can be modified
• distributed with data
• required for new data additions /submissions
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GIS Needs Assessment and Implementation Plan Chapter 6 - Data Standards and Transfer