

Field Map
=========


Offset Length Name                    Notes
------ ------ ----                    -----

    0    40   Filename                Generated from output filename.

   40    60   Producer of Data        Template or blank.

  100     9   Filler                  Blank

  109    26   SW Geographic Corner    Generated. 

  135     1   Process Code            Template or blank. 

  136     1   Filler                  Blank

  137     3   Sectional Indicator     Template or blank.

  140     4   Origin Code             Template or blank.

  144     6   DEM Level Code          Template or blank. 
	                              "1" for PRODUCT=CDED50K

  150     6   Elevation Pattern       Hardcoded to "1" (regular)

  156     6   Horizontal Reference    Hardcoded to "0" (Geographic)
              System

  162     6   UTM/SP Zone             Harcoded to "0".

  168   360   Projection Parameters   Each hardcoded to 0.0.

  528     6   Horz. Unit of Measure   Hardcoded to "3" (arc seconds)
 
  534     6   Vert. Unit of Measure   Hardcoded to "2" (meters)

  540     6   Cov. Polygon Sides      Hardcoded to "4".

  546   192   Corner Coordinates      Generated

  738    24   Minimum Elevation       Generated

  762    24   Maximum Elevation       Generated

  786    24   Rotation Angle          Hardcoded to "0".

  810     6   Accurancy Code          Hardcoded to "0" 

  816    36   Spatial Resolution      X/Y generated, Z hardcoded to 1.0. 

  852    6    Rows of Profiles        Hardcoded to "1".

  858    6    Columns of Profiles     Generated (height of dem in pixels)

  864   12    Largest/Smallest Primary      Blank
              Contour Intervals and Units

  876    4    Data source data        Template or blank.

  880    4    Data inspection or      Template or blank.
              revision date

  884    1    Inspect. Revision Flag  Template or blank.

  885    1    Data Validation Flag    Template or blank.

  886    2    Suspect/Void Flag       Generated (0=none,2=void area)

  888    2    Vertical Datum          Template or "1" (MSL).

  890    2    Horizontal Datum        Template or "4" (NAD83). 

  892    4    Data edition/version    Template or blank. 
              Spec edition/version    "1020" for PRODUCT=CDED50K

  896    4    Percent Void            Generated.

  900    8    Edge Matching Flags     Template or blank.

  908    7    Vertical Datum Shift    Hardcoded to "0.0". 



CDED Production Issues
======================

The following fields should be addressed in a template file. 

Offset Length Name                    Notes
------ ------ ----                    -----

   40    60   Producer of Data        

  135     1   Process Code            The CDED spec lists options as 
                                         "8" = ANUDEM
                                         "9" = FME for LINUX, Build 842
                                         "A" = TopoGrid

  140     4   Origin Code             Should be "YT" in Yukon I believe. 


