Spatial interpolation based on previously-observed behavior: a framework for interpolating spaceborne GNSS-R data from CYGNSS

This study presents a framework for spatially interpolating Cyclone Global Navigation Satellite System (CYGNSS) data over land. The method, Previously-Observed Behavior Interpolation (POBI), assumes that reflectivity data can be interpolated at unsampled locations by quantifying how past observations of reflectivity at the unsampled location varied with past observations of reflectivity at nearby locations. The POBI method is able to recreate truth reflectivity maps with a mean error of 0.17 dB (standard deviation 1.96 dB) and preserves the heterogeneous and discontinuous nature of reflectivity observations. This method is useful for applications that necessitate rapidly-updated data but have some tolerance for uncertainty in interpolated points.