No spatial reference exists Minus and Raster Calculator

[DrewMahedy]

I've been trying to run a difference between two sample bathymetric datasets using either Minus or Raster Calculator. However, I keep getting the following sequence of errors:

For Minus:

ERROR 99999: Error executing function
The table name is invalid.
No spatial reference exists.
ERROR 010302: Unable to create the output raster:  drive:\New_raster
ERROR 010067: Error in executing grid expression.
Failed to execute (Minus)

For RasterCalculator:

ERROR 000539: Error running expression: rcexec() <type 'exceptions.RuntimeError'>: ERROR 010240: Could not save raster dataset to drive:\New_raster

I tried running this process using the rasters as part of file geodatabases and as non-geodatabase tiffs. The projected coordinate systems are the same and the resolution for both is 30 m. Both have a bander number of 1 and are floating point values.

Thanks

[JeffreySwain]

Can you post your syntax for the raster calculator input?

[DrewMahedy]

The syntax I used for the Raster Calculator is:

"Raster1.tif" - "Raster2.tif"

Is there some other syntax I should use? Do the cells need to be aligned spatially?

Thanks

[JennB]

What are your environment settings for raster like? Do they make sense with what you're working on? I've accidentally goofed up my environments before which have caused geoprocessing failures like this.

[JeffreySwain]

Well yes, I would be sure the cell sizes match and the snap raster is used to avoid having to resample during processing.  However, you should definitely have both of the coordinate systems defined.  The default setting in the environment settings for the tool are to follow the input coordinate systems.  If your data is not defined it will not be when you process it.