I am trying to run elevation derivative tools on a provincial DEM provided by the Ontario Government website (Ministry of Natural Resources and Forestry) and I am getting strange values when bringing the data into SAGA GIS.
The values show up like normal in ArcMap but I get an unusually extremely low minimum value (that should be 0) as displayed in the image below:
As displayed, I am currently trying to create a Topographic Position Index (TPI) and the output values are also unusually large. Only when I adjust the min/max values can I get a proper visualization in the display windows, but the metadata in the "Description" tab does not change. On top of that, when I save the SAGA file and bring it into ArcMap I get more strange values. Only when I rescale using the "Rescale by function" (linear transformation function) tool in ArcMap can I get a normal visualization in ArcMap, similar to when I changed the raster's min/max values in SAGA and even then I am unsure if I input the parameters correctly into the ArcMap tool.
Would anyone also know what a typical standard TPI Index value range should be? And would anyone know the proper parameter inputs for a linear transformation function via the "Rescale by function" tool in ArcMap?