How can I update MGRS coordinates in the attribute table of a point feature, when the position of points has been added without using a tool that creates a new feature?
I am not using a special extension for ArcGIS 10.3.
First, make sure both the X and Y fields you already have are up to date, as moving features does not update these automatically. Re-calculate Geometry. In a model, I would make these updates a precondition of the MGRS update step.
I have several short Python field calculation scripts. They are designed for my area of interest, so you will have to generalize this sample:
if (easting < 500000): return "M" else: return "N"
def mgrsn(northing): if (northing < 3900000): return "U" else: return "V" __esri_field_calculator_splitter__ mgrse( !CoordinateX! ) + mgrsn( !CoordinateY! ) + " " + str( !CoordinateX! )[1:6] + " " + str(!CoordinateY!)[2:7]