. How to Evaluate SMAP Radiometer Spatial Resolution Enhancements from Image Reconstruction?

Abstract
After the failure of the SMAP radar in summer 2015, the mission project had to investigate alternative methods for producing soil moisture products at the expected spatial resolution. We are using a radiometer version of the Scatterometer Image Reconstruction (rSIR) algorithm, which we developed for the historical satellite passive microwave record from other sensors, to improve SMAP radiometer resolution. All techniques to transform radiometer data from irregularly-spaced swath format to gridded format are characterized by a tradeoff between noise and spatio-temporal resolution. In related studies on passive microwave data, we determined that exact knowledge of the antenna pattern is not required; effective Enhanced-resolution SMAP soil moisture resolution enhancement can be achieved with an approximate antenna pattern that models the true pattern. Our presentation will describe ongoing work to apply rSIR to improve the resolution of SMAP data, including examples of enhanced-resolution SMAP data and analysis of the tradeoff between noise and resolution.