from the Mars
      Global Surveyor spacecraft at a specified UTC time.

      Use both an ellipsoidal Mars shape model and topographic data
      provided by a DSK file.  For both surface points, use the 'near
      point' and 'nadir' definitions for ellipsoidal and DSK shape
      models, respectively.

      Use converged Newtonian light time and stellar aberration
      corrections.

      The topographic model is based on data from the MGS MOLA DEM
      megr90n000cb, which has a resolution of 4 pixels