SHADED RELIEF MAP OF PHOBOS

Phobos4.jpg is a shaded relief map of Phobos, the inner satellite of 
Mars.  The original map, at much higher resolution than shown here, 
was prepared by the U.S. Geological Survey.  It was described in:

 Batson, R.M., Edwards, K. and Duxbury, T.C., 1992.  Geodesy and 
 cartography of the Martian Satellites, Chapter 36 in Mars (Kieffer, 
 H.H., Jakosky, B.M., Snyder, C.W. and Matthews, M.S., eds), University
 of Arizona Press.

The map as prepared contains many positional errors because of the use
of an inadequate shape model.  I have reprojected the map into the
better geometry of Peter Thomas's shape model (see Phobos.jpg).
For the image presented here, the three dimensional convex hull of the
shape model was projected into the Morphographic Conformal Projection
(the conventional Stereographic Projection modified for non-spherical
worlds).  

The leading side (longitude 90 runs vertically down the centre) faces
forwards in the orbit of Phobos.  The trailing side (longitude 270 runs
vertically down its centre) faces backwards along the orbit.  Longitude
0 is at the more sharply rounded end with the most prominent grooves,
and faces Mars.  As with all conformal (true shape) projections, the
scale in these maps varies, increasing from the centre to the outer edge.

The map projection is described in:

Stooke, P.J. and Keller, C.P., 1990.  "Map Projections for Non-Spherical
Worlds / the Variable-Radius Map Projections", CARTOGRAPHICA, V. 27, No.
2, pp. 82-100.

This version of the file, with labels intact, is in the public domain.

Philip Stooke,
Department of Geography,
University of Western Ontario,
London, Ontario, Canada N6A 5C2
pjstooke@julian.uwo.ca