1. Jet Propulsion Lab.California Inst. of TechnologyMS 183‐501, 4800 Oak Grove DrivePasadenaCA91109
2. Dep. of Soil and Water SciencesUniv. of ArizonaTucsonAZ85721
3. USDA‐SCSNational Soil Survey Lab.Federal Bldg., Rm. 345, 100 Centennial Mall N.LincolnNE68508