First profile outside the BND

Error Message

An error of this type may occur when when trying to convert a text-based USGS DEM file to a grid:

Grid: test1 = demgrid(sd_dem1.dem)
Loading header information...
Datum and Spheroid are missing.
Deducing from DEM projection...
Datum - NAD27, Spheroid - Clarke 1866.
DEM extent [488290.000, 3623380.000, 500000.000, 3637250.000]...
DEM surface range [12.000, 484.000]...
Sample distance in x and y [30.000, 30.000]...
Error: First profile outside the BND.

This has been reported to happen in ArcInfo Workstation 8.x and ArcToolBox 8.x. The DEM files will usually convert in ArcInfo Workstation 7.x.

Cause

This is a data problem. ArcInfo Workstation 8.x makes sure that the BND defined in the header of the DEM file contains all the DEM data. In some older DEMs, the first profile declared its X position to be less than the value defined in the header, which is technically an error condition.

For example, a DEM file declared the XMIN in its header record A as 488290.000. The first profile declared its X position to be 488289.937500, which is less than the minimum x value defined in the header.

In USGS DEMs, the header BND represents the 7.5 minute map quad boundary; thus, the DEM data is supposed to have its origin at the nearest integer multiple of 30 inward from the quad boundary. Some DEM files may not conform with this requirement.

ArcInfo 7.x version can often read these invalid DEMs; however, it must be noted that the result will have an incorrect BND. ArcInfo 8.x checks for these cases and the operation will terminate if the check is not satisfied.

Solution or Workaround

• The most appropriate solution is to obtain new SDTS DEM data from the USGS.
  
  If for some reason the more recent data cannot be obtained, a workaround is to have the file converted in a Workstation 7.x installation.
• As an alternative, you may manually edit the DEM and decrease the header record A XMIN coordinate.
  
  Consult the USGS Web site for details on the structure of DEM files.
  
  Since the original files are considered to be be malformed, ESRI does not assume any responsibility for supporting them.