I am computing the inverse problem where given lat1,lon1,lat2,lon2 the various azimuth's and the distance is computed:
var geod = GeographicLib.Geodesic.WGS84, r; r = geod.Inverse(lat_aid, lon_aid, lat_loc, lon_loc);
The description of the function is given here: https://geographiclib.sourceforge.io/html/classGeographicLib_1_1Geodesic.html
My use case is one where one set of my lat_loc,lon_loc is a given location, and the other set of lat_aid,lon_aid is a navigation aid used to get to the location. I am looking to calculate the distance and bearing from the aid to the location.
Unfortunately I am not a GIS expert or very versed in geography in general and I am have a few questions:
I am having trouble figuring out which azimuth I require (azi2 vs azi1)
Are the calculated azimuths based on grid or true north? Is there any real difference in this model since it estimates the Earth's shape.
The values I get seem to range from 0 to 180 and 0 to -180, am I correct in assuming that a positive azimuth value is clockwise from north, and a negative value is counterclockwise from north? ie: azi -70 would be a bearing of N 70 W and an azimuth of 70 would be N 70 E