Television Frequency Interference in AMSR2 K-Band Measurements Over Reflective Surfaces

The Advanced Microwave Scanning Radiometer 2 (AMSR2) measurements at K-band channels are used for snow retrieval. However, television (TV) signals transmitted from DirecTV satellites at the K-band, if reflected by snow surfaces, could enter the antenna of AMSR2 to introduce errors in AMSR2 snow products. This letter investigates TV frequency interference (TFI) in AMSR2 K-band measurements over areas of land covered with snow. Since a necessary condition for TFI over land to occur is for AMSR2 measurements to have small glint angles, a principal component analysis algorithm constrained by TFI glint angles for TFI detection is thus developed in this letter. Using AMSR2 observations in January 2014, it is shown that TFI signals exist along the two 55 degrees incident angle curves of DirecTV-11 and DirecTV-12, which are located around 44 degrees N over the North American continent.