Impact analysis of MODIS band-to-band registration on its measurements and science data products

Abstract

The Moderate Resolution Imaging Spectroradiometer (MODIS) has 36 spectral bands allocated on four focal plane assemblies (FPAs). Misregistration between bands, namely the band-to-band registration (BBR) shift, has been observed by the on-orbit calibrators. Because of this misregistration, measurements over slightly mismatched areas from different spectral bands can lead to less accurate science data products when they are used together. In this article, the impact caused by the BBR shift on Level 1B (L1B) measurements is assessed. The relative error is fairly large at both ends of a swath in the scan direction because of the bow-tie effect. In the track direction, the impact has a quasi-linear trend. In practice, the impact of misregistration on L1B measurements is less than 0.1%. The estimation of the potential impact on science data products caused by misregistration is performed with a case study. As expected, the impact on science data products is negligible at homogeneous areas but becomes larger at non-homogeneous areas.