An L-band direct sampling digital radiometer for STAR technology sensors

A well understood need has emerged for global, near-daily, estimates of the water stored in soil, snow, and vegetation that is available both to the atmosphere through evaporation and transpiration, and to agriculture. These estimates should be at the scale of future, higher resolution mesoscale atmospheric models, i.e., something like 10 km. We can produce these estimates through satellite remote sensing of moisture in the upper 5 cm of soil. Stored water is a product of assimilating into land-surface process models the near-surface soil moisture at a spatial scale of significant precipitation events and a temporal scale of moisture retention in near-surface soils. The challenge for remote sensing technologists is to converge upon sensor technologies that will meet observational requirements at affordable development and operational costs. For many reasons, we believe that the appropriate sensor is an L-band radiometer based upon Synthetic Thinned Array Radiometry (STAR) technology