How to convert AngularUnits (Degrees) to LinearUnits (Meters?)

Question

Polyline.Lengths returns Degrees (as defined per SpatialReference.Unit,) but I would rougher display it in meters.

However AngularUnit does not have a ConvertToMeters methods...

(B.T.W the snippet "LinearUnit - Convert between centimeters and millimeters" is so pathetic...)

ThomasEmge · Answer

The geodesic length is providing shortest path on the ellipsoid. Depending on the length of your geometry you will indeeed see a difference in the actual length value for computed planar length or geodesic length - in either case the GeodesicLength method will provide you the answer in meter in the case the original geometry is a geographic coordinate system.

It is not possible to just convert an angular unit value to a linear unit as there is a dependency on the location on the sphere/geoid/ellipsoid. To transform the information from a geographic coordinate system to a projected system (using linear units) you need to project the geometry. Here is a very nice description about the principles of map projections.

For code examples please take at look at this location.

- Thomas

HoriaTudosie · Answer

Not Exactly:

While measuring Geodesic lengths is nice, It does not interest me much since I measure roads length.

However the result I get is in Degrees, and I would want it in Meters, which others have given hints but not solutions (like in code...)

ThomasEmge · Answer

I believe you are looking for this ArcGIS Pro 1.3 API Reference Guide