proj_bearing_use_datum option
This command specifies how projection bearing coordinate systems are applied. The projection bearing coordinate system must be a coordinate system defined in the snap coordinate system definition file. This defines the parameters used to calculate projection coordinates, and hence projection bearings, from the station coordinates. By default SNAP checks that the datum of the projection coordinate system is the same as that of the network station coordinates and fails with an error if these do not match. However SNAP can ignore the datum difference, and just use the projection parameters for this calculation. This is typically done to ignore differences in the version of the datum, for example using a projection coordinate system of EDENTM2000 with a network coordinate system of NZGD2000_20160701.
The parameter of the command is:
option
can be "yes" or "no". If it is yes (the default) then projection bearings are calculated strictly, if it is no then differences between the projection bearing coordinate system datum and the network coordinate system datum are ignored.