Slide 1

Two modes: (1) stop and measure (SAM); (2) drive and measure (DAM). Can do: (1) 1-D transects. (2) 2-D maps. Mobile sensing of surface moisture: COSMOS rover Slide 2 COSMOS rover transect, Hawaii Slide 3 Elevation and forest Rainfall COSMOS rover map, Hawaii Slide 4 One scale: 36 km x 36 km Neutron intensity and water content at four scales: 36 km x 36 km:206 cpm, 14% 9 km x 9 km:206 cpm,14% 3 km x 3 km:199 cpm,15% 1 km x 1 km:209 cpm,13% COSMOS rover map, Oklahoma Slide 5 Monthly maps, except during summer monsoon - weekly. Calibrated at a stationary COSMOS site. COSMOS rover map, Tucson Basin Slide 6 COSMOS rover map, Oklahoma Slide 7 (1) Fast mapping of soil moisture over large areas and over variable terrains (2) Possible with different moving platforms: cars (done, working well) aircraft (in progress, likely to work) on foot (backpack rover) trains (future, likely to work) Advantages of the COSMOS rover Slide 8 (1) Precision depends on velocity trade-off between efficiency and precision and between efficiency and spatial resolution (2) Conversion to soil moisture usually unalibrated: must use universal calibration lattice water unknown and variable - must estimate - how? soil organic C unknown and variable - must estimate - how? vegetation variable and unknown - must estimate - how? contribution of road to neutron intensity - how to remove? Challenges unique to the COSMOS rover Slide 9 Lattice water, USA Slide 10 Organic carbon, USA