Proximity has developed national scope Geographic Reference Files (GRFs) and related GRF processing software described in this section.

Benefits/Uses. Do you have need for address-matching capabilities? Have you used the Census Bureau Census Street Tract Index resources and are now looking for a similar capability that makes use of the Census 2000 geographic codes and demographics? Do you need TIGER/Line files structured in database format for relational queries and file/code cross-referencing? The GRF files and software respond to all of these needs and provide examples of the ways that you can benefit from their use.

Components of the GRF program include:

  • GRF Match/Code (GRFMC) software
  • Geographic Reference Files
  • TGR2DBF software

More information is provided on each component by clicking on the links provided above. Each of these resources can be acquired from Proximity. An overview of the components and how they relate to various uses and applications is provided below. Please e-mail us at (support@proximityone.com) for additional information about the GRF resources.

Origin and Component Relations. Origin of the GRF program starts with the Proximity need to have an easy way to access/process the Census Bureau TIGER/Line files (see this overview of the TIGER/Line files) in a database structure, to meet a range of application needs. We first developed CD-ROMs containing the TIGER/Line files (TLF) in zip file structure (although the files could be order directly from the Census Bureau). These files are the Census 2000 version TLFs zip files developed by the Census Bureau. The CD-ROM TLF files may be unzipped by the application program, TGR2DBF.

The main purpose of TGR2DBF is to provide software that can convert the TLFs into a database structure and perform related TLF custom file generation and processing operations. The TGR2DBF software is used to create the TIGER Geographic Reference Files (GRFs).

A main role of the GRF is to serve as a base file that can be used in simple address-matching, lookups, and related applications. TGR2DBF builds the GRF, on a county-by-county basis, by processing the TIGER/Line file RT1 (record type 1) file which are categorized as road/streets (Census feature class code "A"). The GRF file contains on the most basic TLF RT1 files required to support basic address matching and related lookup operations.

Address-matching and address lookups are widely used applications for files derived from the TIGER/Line files. The GRF Match/Code software enables address-matching, geocoding, and address-lookups.

GRF Match/Code Software [goto top]

The GRF Match/Code software has been developed to process user supplied, site-oriented data, with Geographic Reference Files. "Site-oriented data" are most typically address-oriented data (where the user has data records by address that they seek to geocode). The GRF Match/Code (GRFMC) software includes these features:
  • Lookup of a single address keyed into a GRFMC screen
    returning census tract code, related site location codes,
    and latitude-longitude.
  • Lookup of a single address keyed into a GRFMC screen
    returning a demographic profile of the area containing the address.
  • Batch processing a set of user supplied address records
    generating a file with GRF-sourced geocodes, lat-long,
    and user defined set of demographic fields.

The GRF Match/Code software is the primary "end-use" software/enabling capacity of the GRF data resources and software program. Users may acquire only the GRF Match/Code software and the GRF(s) for their areas and proceed to use the resources. Users with more extensive requirements may be interested in acquiring the more "developer oriented" TGR2DBF software and TIGER/Line files further described below.

TGR2DBF Software [goto top]

The TGR2DBF has been developed to convert Census 2000 TIGER/Line files to a database structure and generate Geographic Reference Files (GRFs). GRFs are similar to the Census Tract Street Index (CTSI) files developed by the Census Bureau for the 1990 Census.

You can acquire GRFs from Proximity, further described below, or develop GRFs yourself using no-fee Census 2000 TIGER/Line files with the TGR2DBF software.

The TGR2DBF software includes these features:

  • Automatic unzipping and conversion of ASCII TIGER/Line files
    to dBASE4 structured files (all record types or selectively)
  • Processing the TLFs for an individual county or entire state via menu option
  • Automatic optional generation of the GRF for TLFs processed
  • Optional GRF dBASE file append feature to build a statewide
    (US or any region) GRF
  • Ability to generate census block-to-urban area code equivalency file

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Geographic Reference Files

Geographic Reference Files (GRFs) are based on Census 2000 UA Version TIGER/Line files (May 2002) and developed using the TGR2DBF software. GRFs are similar to the Census Tract Street Index (CTSI) files developed by the Census Bureau for the 1990 Census.

GRF's may be acquired organized on a county-by-county, statewide, or national scope coverage for use with the GRF Match/Code software (or your own software). Or, you can use the TGR2DBF software to create you own versions of GRFs that meet custom needs (the basic GRF is designed to meet most widely used match/coding requirements -- using TGR2DBF you can expand the scope of GRF fields/content).

GRFs as distributed by Proximity are organized as generic dBASE4 files. The data fields included in the GRF are standardized and described in the table presented below.

Geographic Reference File Data Fields

Name	Width	Description
TLID	10	TIGER/Line Record ID
FEDIRP	2	Feature Direction Prefix
FENAME	30	Feature Name
FETYPE	4	Feature Type
FEDIRS	2	Feature Direction Suffix
FRADDL	11	From Address Left Side
TOADDL	11	To Address Left Side
FRADDR	11	From Address Right Side
TOADDR	11	To Address Right Side
ZIPL	5	ZIP Code Left Side
ZIPR	5	ZIP Code Right Side
STATEL	2	State FIPS Code Left Side
STATER	2	State FIPS Code Right Side
COUNTYL	3	County FIPS Code Left Side
COUNTYR	3	County FIPS Code Right Side
PLACEL	3	Place FIPS Code Left Side
PLACER	3	Place FIPS Code Right Side
TRACTL	6	Census 2000 Tract Code Left Side
TRACTR	6	Census 2000 Tract Code Right Side
BLOCKL	4	Census 2000 Block Code Left Side
BLOCKR	4	Census 2000 Block Code Right Side
FRLONG	10	From Node Longitude
FRLAT	9	From Node Latitude
TOLONG	10	To Node Longitude
TOLAT	9	To Node Latitude

Additional Information
Proximity develops geodemographic-economic data and analytical tools and helps organizations knit together and use diverse data in a decision-making and analytical framework. We develop custom demographic/economic estimates and projections, develop geographic and geocoded address files, and assist with impact and geospatial analyses. Wide-ranging organizations use our tools (software, data, methodologies) to analyze their own data integrated with other data. Contact Proximity (888-364-7656) with questions about data covered in this section or to discuss custom estimates, projections or analyses for your areas of interest.