Convert Range, Azimuth and Elevation to Latitude-Longitude

Topics: Algorithms, General Topics, SharpMap v0.9 / v1.x, WinForms Controls
Sep 21, 2009 at 4:41 PM

Hi,

I am a GIS-newbie that need some help...

I have some recorded radar data; range, azimuth and elevation relative to the radar station. The latitude and longitude for the radar station is known. How can I use SharpMap (V0.9) to calculate longitude and latitude for the radar data?

Thanks in advance / Mattias

 

Coordinator
Sep 22, 2009 at 5:51 PM

Hi Mattias, are you trying to do this in a planar or geographic coordinate system? Can you give some example data and expected result. Cheers jd

Sep 23, 2009 at 12:30 PM

Hi again,

each radar observation has:

Range = The distance in Nautical miles to the object

Azimuth = The angle, 0-360, (from north and clockwise) to the object as seen from straight above.

Elevation = The angle, 0-90, to the object from the ground plane.

Using the above values I can easily calculate X, Y and Z in Nautical miles using the radar station as origo. The question is how do I go from these X, Y, Z values to longitude and latiude?

Regards / Mattias

Coordinator
Sep 23, 2009 at 3:22 PM

You would use a CoordinateTransformation between the local coordinate system that the position of the radar station is measured in and WGS84.

This functionality is in the projnet dll (in the external references folder) . The project home is http://projnet.codeplex.com but beware that the version in the sharpmap tree is old and incompatible with the lastest proj net.

http://projnet.codeplex.com/Wiki/View.aspx?title=CreateProjection&referringTitle=Home may be useful

hth jd

Mar 10, 2010 at 4:54 PM

I need to display target on radar display while i can get the input values of azimuth and range. Is it possible to show it on XY- coordinate system. If it is possible give the code  in c# language.