Estimation of Land Surface Temperature Using Spatial Interpolation and Satellite-Derived Surface Emissivity

Abstract

This study presents a method to estimate land surface temperature (LST) by calibrating spatial interpolation using satellite-derived surface emissivity. Four spatial interpolation methods including Inverse Distance Weighting (IDW), Spline, Kriging, and Cokriging were tested to interpolate LST in southern New England using ground temperatures measured at national weather stations (NWS) in summer 2001. The performance of each interpolation method was evaluated using field measurements collected in a mixed forest in Connecticut during the study period. Kriging is recommended for LST interpolation when surface emissivity data are not available. By analyzing the field data, we found that the maximum daily interpolation error occurred in the early morning and the minimum error occurred at around hour 18:00. Validation result shows that the accuracy of spatial interpolation of LST was much improved after being calibrated by satellite-derived surface emissivity. The average interpolation error reduced from 10 °C before calibration to 1.56 °C after calibration.

Keywords: Land surface temperature, spatial interpolation, surface emissivity