Quantitative comparison of the operational NOAA-AVHRR LST product of DLR and the MODIS LST product V005

摘要

Land surface temperature (LST) products of two different sensors - the Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) - were cross-compared. The analysis was conducted on a daily basis for four different years. Only pixels that stuck to certain homogeneity criteria were chosen. Furthermore, a time criterion defining the maximal time difference between two acquisitions was introduced. The differences between the two products showed both a diurnal and an annual pattern, with LST of AVHRR being higher than that of MODIS at high surface temperatures and AVHRR LST being lower than MODIS LST at lower temperatures. Additionally, some irregular patterns were identified and attributed to the different algorithm approaches. Mean annual absolute differences were relatively low: only 2.2 K for the daytime and 1.4 K for the night-time scenes, speaking for a general good agreement between the two products. The coefficient of determination (R~2) between the LST of AVHRR and MODIS of both day and night scenes was 0.99.