Impacts on the TRMM data due to orbit boost in the spectral domain

The Tropical Rainfall Measuring Mission (TRMM) was extended by the boost to a higher altitude in August, 2001 to gain further benefits in operational weather forecasting and climate research. To establish the credibility of TRMM data, it is necessary to analyze the impacts of orbit boost on TRMM rainfall data retrieval. In this study, the orbital boost's effects are investigated in the spectral domain by comparison with other data sets not affected by boost. The TRMM boost introduces spurious spectral biases differences between pre- and post-boost periods and the independent sampling error study is used to ascertain them. The boost effects are usually exposed as small-scale, high-frequency wave signals in TRMM infrared radiation (IR) and microwave imager (TMI) data sets, whereas the spurious spectral differences between the two periods are not as clear in TRMM precipitation radar (PR) data due to the small sampling.