Spatial Resolution Enhancement Algorithm Based on the Backus&x2013;Gilbert Method and Its Application to GCOM-W AMSR2 Data

The greatest advantage of a satellite-borne microwave radiometer (MWR) is that it can obtain information on the Earth & x2019;s surface with less influence by rain and clouds compared to an infrared radiometer; however, it has the disadvantage that the observing area is large so the spatial resolution is low. One example is the Advanced Microwave Scanning Radiometer-2 (AMSR2) loaded on the GCOM-W satellite. Hardware technologies to overcome this disadvantage are in progress, but software processings to improve spatial resolution are also needed, especially to process previously obtained data. The author was inspired by the experience of developing the L1R product for the AMSR2 and has investigated optimizing the Backus & x2013;Gilbert (BG) method to enhance spatial resolution. First, the BG method was used to calculate weighting coefficients to synthesize the brightness temperature equivalently obtained in a small observation area from those obtained in multiple larger areas. Next, a viable algorithm was developed and implemented in order to solve the problem appearing in this simple application of the BG method. The algorithm was verified and shown to reduce the observation area by about 17 & x0025;, enhancing the spatial resolution.