l rotate one of the
         FOV boundary vectors from the camera frame at `etrec' to the
         body-fixed Mars frame at `etemit', and call the faster routine
         `<a href="surfpt_c.html">surfpt_c</a>' to retrieve the surface point for one of the FOV
         boundary vectors.
 
         This example problem could be extended to find the latitude
         and longitude associated with every pixel in an instrument's
         field of view, but this example is simplified to only solve
         for two