[1] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
[2] Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA
[3] Univ Arizona, Inst Atmospher Phys, Tucson, AZ 85721 USA
[4] Los Alamos Natl Lab, Nonproliferat & Int Secur, Los Alamos, NM 87545 USA
[5] Univ Miami, Dept Phys, Coral Gables, FL 33124 USA
[6] Univ London Univ Coll, Dept Geomat Engn, London WC1E 6BT, England
[7] Boston Univ, Dept Geog, Boston, MA 02215 USA
[8] NASA, Johnson Space Ctr, Houston, TX 77058 USA
[9] EC Joint Res Ctr, Space Applicat Inst, I-21020 Ispra, VA, Italy