Lambert Conformal Conic

Dear GM,

I prepared a workspace with Lambert Conformal conic and I overlaid a DWG file using the projection Lambert Conformal Conic. The problem is when I rectified to the said projection,  my DWG file vertices not showing correct WGS84 coordinates 25 40 55.3N 051 33 45E but in this format 4994330.67630842 4587063.03624404. Is there something I miss in the transformation parameters, if so what should be the parameters?

Your assistance on the above is highly appreciated.


Regards,


Roel

Answers

  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,873
    The coordinates you are seeing are reasonable for the Lambert Conformal Conic projection -- you would not see latitude and longitude coordinates in that case.  What are you trying to do?  Are you trying to reproject your Lambert Conformal Conic data to Geodetic WGS84?  What projection is your original DWG file using?  What version of Global Mapper are you using?
  • Tks for the reply, I am using GM ver 13 and the DWG is in local grid. I am experimenting to capture airport mapping elements such as runways and taxiways geometry, somehow when I tried to overlay the dwg and do the rectification using control points and selected "YES" (system to automatically select projection) it fits to the right position but not giving me the correct lat/long for the vertices. Is there a way to set the parameters to transform to wgs84? or a work around for this process, I tried to used Geographic projection, in a way it gives me the correct vertices but the rectified drawing is a little bit skewed (is it normal for GEO projection?).

  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,873

    Tks for the reply, I am using GM ver 13 and the DWG is in local grid. I am experimenting to capture airport mapping elements such as runways and taxiways geometry, somehow when I tried to overlay the dwg and do the rectification using control points and selected "YES" (system to automatically select projection) it fits to the right position but not giving me the correct lat/long for the vertices. Is there a way to set the parameters to transform to wgs84? or a work around for this process, I tried to used Geographic projection, in a way it gives me the correct vertices but the rectified drawing is a little bit skewed (is it normal for GEO projection?).

    You say that GM is "not giving me the correct lat/long for the vertices".  How are you determining the latitude and longitude for a vertex?  How far off are the latitude and longitude?  You say that you are using Lambert Conformal Conic as your projection.  What datum are you using?  Is it WGS84?

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