Re: Spatial Reference Code for Calculating Geometry

Question

Randy,

Thanks for the code snippet.  I’ll give it a try.  If it works properly then I’ll need to incorporate into bigger script.

Regards,

Jim

JimFritz · Answer

Hi Melita,

I have side question.  Is there a way to project a DEM raster, from geographic to UTM15N US feet, so that the grid code z-value changes from meters to feet?  Do you have to go into the spatial reference properties and the "Z coordinate system" tab and pick from there (see image below)?  If so, what would the best parameter to use.

It seems that without setting a z value no change conversion to feet is evident after running Project Raster.

Thank-You,

Jim

JimFritz · Answer

Here is the final script that seemed to do the trick: This script will loop thru and calculate geometry fields X_coord and Y_coord from geographic to NAD_83_UTM_Zone_15N_Feet import arcpy arcpy.env.overwriteOutput = 1 outrastertopoint = r"S:/General-Offices-GO-Trans/SLR-Mapping/GIS_Projects_2018/Smart_T_Line_Model/geodata/NSP_RASTERTOPOINT_FT.gdb/" arcpy.env.workspace = outrastertopoint fieldName1 = "X_coord" fieldPrecision1 = 9 fieldAlias1 = "longitude" fieldName2 = "Y_coord" fieldPrecision2 = 9 fieldAlias2 = "latitude" #Spatial reference set using .prj file. False easting field is key to get positive values in X_coord. sr = arcpy.SpatialReference(r"S:\General-Offices-GO-Trans\SLR-Mapping\GIS_Projects_2018\Smart_T_Line_Model\geodata\coord_sys_UTM15FT.prj") #Loop thru list of 1,455 features featureClassList = arcpy.ListFeatureClasses() for featureClass in featureClassList: arcpy.management.CalculateGeometryAttributes(featureClass, "X_coord POINT_X;Y_coord POINT_Y", None, None, sr)‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

MelitaKennedy · Answer

The false easting/false northing values have to use the same linear unit as the projected coordinate system itself. The well-known text string is using international feet (1 ft = 0.3048 m) but the false easting value is defined in meters.