Estimation of Land Surface Temperature from Unmanned Aerial Vehicle Loaded Thermal Imager Data

This paper proposed a workflow to estimate land surface temperature (LST) from unmanned aerial vehicle (UVA) loaded thermal infrared imager FLIR data. The radiance received at the FLIR's sensor (ZENMUSE XT) was assumed to be the sum of the radiance from the land surface itself and the reflected downward atmospheric radiation, ignoring the upward atmospheric radiation due to UVA's low-altitude flying. The total radiation from the land and the downward atmospheric radiation were calculated from the brightness temperature extracted from the thermal image shot on the land surface and into the sky, respectively, over a farmland field at Shunyi District, Beijing, on October 27, 2017. The emissivity of the winter wheat was measured by the Portable Fourier transform thermal infrared spectrometer (102F). Finally, LST in a target scene was estimated. The range of LST in this area is around 27.8~36.5 °C. A well textual feature was depicted owing to the relatively high resolution of the UAV data.