Mitigating and comparing the striping noise in FengYun‐3B/C/D microwave radiation imager brightness temperature observations

Abstract

AbstractThe Microwave Radiation Imager (MWRI) on board the FengYun‐3 (FY‐3) series of satellites can provide global observations four times daily, which significantly improves the ability to monitor large‐scale natural disasters. There is noticeable striping noise in brightness temperature observations from the MWRIs on board the FY‐3B, FY‐3C and FY‐3D satellites. The central frequencies of all MWRI channels are in the atmospheric window region. In this article, a modified principal component analysis/ensemble empirical mode decomposition method proposed by Zou et al. in 2017 was applied to deal with the striping noise in MWRI measurements. Results reveal that the magnitude of the striping noise in the brightness temperature observations of MWRI channels 10 are about ±1.2 K for FY‐3B, ±1.1 K for FY‐3C and ± 0.8 K for FY3D. The striping noise in FY‐3D MWRI measurements is significantly reduced, compared with the striping noise in FY‐3B and FY‐3C MWRI measurements. Striping features will appear in the liquid water path (LWP) distribution if LWP is retrieved from brightness temperatures without removing the striping noise. The differences between LWP retrieved from the MWRI observations with and without striping noise mitigation could be as large as 0.07 kg·m−2. It is thus necessary to remove striping noise before any MWRI data applications.