[GIS] Adjusting UTM and geographic coordinate data

coordinatesutm

I have a dataset with several points in space within a given area. UTM coordinates (easting, northing in m) or geographic coordinates were recorded for a single point in the vicinity of these points. Then, locations of each of the other points was recorded based on the distance of a given point along the x- and y-axes (e.g. 5 m, 7 m) from the point where UTM or geographic coordinates were recorded.

Now, how can I determine the UTM coordinates or geographic coordinates of each of these points based on the x,y distances from the point where UTM or geographic coordinates were recorded?

Isn't it appropriate to simply just add the x and y distances to the utm coordinates of the known point to determine the unknown utm co-ordinates of the other points (then use a utm to lat-long converter for determining geographic coordinates)?

Best Answer

If I understand the problem correctly, it sounds like you have control points in both UTM and geographic (Lat/Lon) coordinates, and you have offsets measured in meters from these control points, and you need to calculate the locations of those offset points in either UTM or Lat/Lon?

I would start by getting all of the control points in one system, and since your offsets are measured in meters, it would make most sense to convert the geographic coordinates of your control points so that all are in UTM, then add the offsets to the eastings (x) and northings (y) to get the coordinates of the offset points.

The UTM coordinate system was partly developed for these types of applications. Plotting everything on a grid of square meters made it easier to calculate distances and directions for artillery using tables of cosines and square roots than it was using nasty spherical coordinates.