This may result in considerably
brighter radar returns. Though dielectric constants were not measured between
radar passes, soil moisture levels were measured on the playa at a field site
south of the shoreline features and south-west of the series of drainages
during summer 1999 (Figs. 3 and 4). Field soil samples were collected in the
upper 0–5 cm of the soil profile within 6 h of the image acquisitions. The
soil moisture was measured by the oven-dried method in accordance with
ASTM D 2216-90 (Bowles, 1992) in a laboratory at the University of Nevada,
Reno. The moisture content is defined herein as the ratio of mass of water present in
a soil mass to the mass of soil solids. The mean soil moisture in the July 30, 1999
samples was 16.2%. That for the August imaging date was substantially greater
at 33.8%.