Sample Rasters Listed in Fields fails with ArcGISError: ... Invocation of Describe(*args=(u'...',)) raised COM Error 0x80020009: "Exception occurred.".

[jjr8]

Here is a complete log output:

Executing (Sample Rasters Listed in Fields): ArcGISRasterSamplerSampleRastersInFields E:\HabModExample2\Geodatabase.mdb\PointsToSample ChlorophyllRaster;SSTRaster;SSTQualRaster Chlorophyll;SST;SSTQual # NEAREST # value;value;int(value) # E:\HabModExample2\Geodatabase.mdb\PointsToSample
Start Time: Tue Jun 09 12:08:00 2009
Running script ArcGISRasterSamplerSampleRastersInFields...
Sampling rasters: points=E:\HabModExample2\Geodatabase.mdb\PointsToSample, rasterFields=[u'ChlorophyllRaster', u'SSTRaster', u'SSTQualRaster'], sampledValueFields=[u'Chlorophyll', u'SST', u'SSTQual']...
Querying the feature class to determine the number of required sample operations.
Query complete: 0:00:01 elapsed, 600 rows retrieved, 0:00:00.002270 per row.
7 sample operations are required.
Performing sample operation 1.
ArcGISError: An ArcGIS geoprocessing function failed. This usually results from a problem with your inputs. Please check them and try again. Also review any preceding error messages and the detailed error information that appears at the end of this message. If you suspect the failure is due to a programming mistake in this tool or ArcGIS, please contact the author of this tool for assistance. Detailed error information: ArcGIS Geoprocessor object 0x00F9A350: Invocation of Describe(*args=(u'C:\\HabModExample2\\OceanographyRasters\\Chl\\8Day\\chl1999233',)) raised COM Error 0x80020009: "Exception occurred.". Error details: source="esriSystem.AoInitialize.1", description="ArcObjects has not yet been initialized", scode=0x80004005 ("Unspecified error
"). More information may be found under topic 0 of help file "esri_csGeoDatabase.hlp".
The following consequences resulted from the original error:
Sampling failed.
Error in script ArcGISRasterSamplerSampleRastersInFields.
Error in executing: cmd.exe /C C:\PROGRA~1\GeoEco\ARCGIS~1\Scripts\AR88B7~1.PY  "E:\HabModExample2\Geodatabase.mdb\PointsToSample" "ChlorophyllRaster;SSTRaster;SSTQualRaster" "Chlorophyll;SST;SSTQual" "#" "NEAREST" "#" "value;value;int(value)" "#" "E:\HabModExample2\Geodatabase.mdb\PointsToSample"

Failed to execute (Sample Rasters Listed in Fields).
End Time: Tue Jun 09 12:08:46 2009 (Elapsed Time: 46.00 seconds)

This happens on ArcGIS 9.2 SP6 when the raster that is being sampled does not exist. I consider this behavior a bug in ArcGIS; the gp.Describe function should report a better error message. To work around this, I should modify the tool to call gp.Exists prior to calling gp.Describe.

I have not tested for this specific problem with other releases of ArcGIS. They may work differently.

We should look at fixing this when we rewrite the sampling tools, ideally in MGET 0.8.