http://clementine.cnes.fr/help/echelle.en.html (Internet on a CD, 07/1998)
Scale
HORIZONTAL_PIXEL_SCALE = xxxxx.xxxx
Distance, measured along horizontal direction, along target surface and right edges of pixel-sized region in FOV centered at camera boresight. Defined only when boresight intercepts surface. Units are in kilometers.
http://clementine.cnes.fr/help/echelle.en.html (Internet on a CD, 07/1998)
