"ERROR 000151: The geotransformation (s) is not valid"

[MarkNorris-Rogers]

I have a Lidar-derived DEM in a GCS_Arc1950 projection with the D_Arc1950 datum.

Full details: PROJCS['GCS_ARC1950',GEOGCS['GCS_Arc_1950',DATUM['D_Arc_1950',SPHEROID['Clarke_1880',6378249.144808011,293.4663076556253]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]],PROJECTION['Transverse_Mercator'],PARAMETER['false_easting',500000.0],PARAMETER['false_northing',10000000.0],PARAMETER['central_meridian',33.0],PARAMETER['scale_factor',0.9996],PARAMETER['latitude_of_origin',0.0],UNIT['Meter',1.0]]

I need to transform it to WGS_1984_UTM_Zone_36S. I used the standard ArcGIS 10.5 Project Raster tool and applied the default ArcGIS transformation file Arc_1950_To_WGS_1984_5. However, it failed, giving an "ERROR 000151: The geotransformation (s) is not valid". I have also tried creating a custom transformation file using the published parameters for the Malawi Arc 1950 Datum to WGS84 (Mugnier CJ, 2011, PERS) but got the same ERROR message. Because the Arc1950 is based on the Cape Datum, I tried defining its projection as a Cape Datum, and transform it using the standard Cape to WGS84 transformation. That worked! I did this simply to see if I would receive the same error message.

The source data is in a FGDB

When reviewing the Geoprocessing Results info, under Environments, it lists the Geographic Transformation as NAD1927 to NAD1983 NADCON. However in my Environment Settings are as follows:

I assume the NADCON setting is some sort of default value and does not influence the actual processing??? Where does it come from?

What am I missing?? Thanks very much.

[MelitaKennedy · Accepted solution]

The software doesn't like the definition of your data. Try redefining it as Arc 1950 UTM zone 36S (in the UTM, Africa folder). The ellipsoid parameters are slightly different, but enough that the software doesn't recognize it as Arc 1950.

Melita

[MarkNorris-Rogers]

Thanks so much Melita! That worked.

How can I see the parameters of the built-in Esri transformation files, eg. Arc_1950_To_WGS_1984_5?

Thanks again

[MelitaKennedy]

Hi Mark, 

In your desktop install folder, look in the documentation folder for geographic_transformations.pdf. It has the parameter values and the extents of the transformations. There's a direct link to it in the help. Look in the map projections section, first topic, bottom of the page.

There's also this knowledge base article which has links to various versions of the PDF file.

[MarkNorris-Rogers]

Hi Melita,

Thanks again! That is a really useful resource, but one I was unaware of despite 20 years of working with Esri software. Obviously I have not been paying attention 😞 

I was helping someone else with this query, so at least 2 of us have learnt something new. Really appreciate that! Thanks very much.

Mark