Conversion XY coordinates at geodesics

[Quasar]

Good to all,

first of all apologize for my poor English language skills. I'm from Spain and need to know how I can make a LISP routine to convert Autocad XY coordinates in geodetic coordinates. That is, select any point in autocad and returns the value in format, for example, 421731N, 0080739W .. any idea?

 

Thank you so much

[Commandobill]

If you are using map 3d and you are using a latitude longitude coordinate system it's quite a simple process just to add an n and a w on the end of the points you receive. I guess i should ask. What coordinate system are you using?

[Quasar]

Thank you for respond.

 

The geographic coordinate system is WGS84. How is exactly this process 3D map? I go further ... if I want to work in AutoCAD, how do I implement a LISP routine that can perform this process? Thanks for your patience.

[tagkelas]

OK WGS84 but what's "your" Geodetic Datum?

I think your question is general...

 

This routine is made for transformation from ED50 to ITRF89 in GRS80

http://www.cadtutor.net/forum/showthread.php?t=31972

[Quasar]

Thanks for your reply.

The Datum is ED50 and Huso30. The specific problem is to convert UTM to geodetic coordinates using equations Coticchia-Surace.

That is, suppose coordinates UTM X and UTM Y are respectively X =- 287.1945 Y = 140.0603.

Well, I need these points, when are selected, autocad return the coordinates in format latitude=423920N and longitude=0080908W. (As the format used by Google Earth). Is there any way to do this in 3D MAP? Is there a lisp routine that I can do?

 

 

Thanks in advance.

[tagkelas]

I "googled" equations Coticchia-Surace and I saw this one:

http://foro.gabrielortiz.com/comparte/repositorio/Gabriel/Geograficas-UTM_Hoja_A1.pdf

It not the complete solution.

After you find φ,λ (in the bottom of the page- "Calcula Final de Coordenadas Geograficas")

You have to find X,Y,Z (geocentric cartesian coordinates in ED50)

Then using for ED50-WGS84 Delta s (dX=83.50,dY=96.30,dZ=115.70) you find geocentric cartesian coordinates in WGS84 and then you will find latitude and longitude in WGS84

 

As you see the equations is a little difficult to use them in a lisp routine. I do not know if any other member of the forum tried it, because I am interested too