Contents of the GCDB for Arizona        August 2017


Coverages subdirectory includes:
  - Coverages of each township in Arizona.  These are zipped into files with
    names like az14t03__n00__e.zip.  In this example, the townships included
    are townships 30-39 north, ranges 01-09 east. The coverages are in NAD27.

Survey Data - Gila and Salt River Meridian subdirectory includes:
  - Flat files created by our data collection software WinGMM. These are based
    on NAD27.  Each township has a directory. There are 3409 townships in Gila
    and Salt River Meridian

Survey Data - Navajo Special Meridian subdirectory includes:
  - Flat files created by our data collection software WinGMM. These are based
    on NAD27.  Each township has a directory. T05NR10W is the only recognized
    township in the Navajo Special Meridian.  All others have been cancelled.

Survey Data - San Bernardino Meridian subdirectory includes:
  - Flat files created by our data collection software WinGMM. These are based
    on NAD27.  Each township has a directory. There are 4 townships in the
    San Bernardino Meridian.

Flat_File_Support subdirectory  includes:

  - documentation of the file and point naming conventions used in GCDB.

  - documentation of the file format for common flat files in GCDB.

  - WinGMM software which allows viewing\editing of the data, coordinate
    zone/datum transformations, as well as creation of .DXF files for AutoCAD.

  - LX2GPX2, a new program that extracts selected points from the township.LX
    file and creates either a township.GRM file or a township.GPX file.  The
    .GRM file has waypoints that can be loaded into a GPS device using common
    GPS software. The .GPX file can be read and displayed by Google Earth.


                           It needs to be said:

The Geographic Coordinate Data Base, GCDB, is a useful representation of the
geometry and topology of parcels contained within the PLSS and other
boundaries of federal interest, but its application is intended for mapping
purposes only. The GCDB is not a substitute for a legal land survey.