I am a Land Surveyor and I am writing a land surveying computer
progam. In it , I need to calculate the Grid Distance of a measured
EDM distance. In other words, I need to calculate the Scale factor for
each measured EDM distance in order to convert them to Grid Distances.
I need you to give me the general formula well documented for the
scale factor calculation so that I can code it into my program. I work
in St. Lucia in the West Indies. I would be grateful if you could
include the parameters for the map projection and geoid for St. Lucia,
however, it is not essential since I can get it myself.