An operational Airborne-Ground Integrate observation scheme for validating land surface temperature over heterogeneous surface

• The errors between UAV LST and the ground observations were corrected, providing a scalable scheme to the uncertainties of airborne-based observations. • The accuracy and performance of the medium-resolution satellite on heterogeneous surfaces were validated using the corrected UAV LST as the “true value”. • The relevant impact of surface heterogeneity continues to be discussed in depth in the satellite validation work. At present, there are more than 30 satellite remote sensing Land Surface Temperature (LST) products from kilometers to hectometers resolutions. The accuracy of these products is the key issue for further application. The validation of LST products is mainly achieved through ground observations on homogeneous surfaces, but the accuracy of satellite products on heterogeneous surfaces is also an important factor in the performance of satellite products. We proposed an integrated airborne-ground observation scheme to validate the accuracy of hectometers Landsat LST product. Firstly, in this scheme, the optimal deployment of ground observations is constructed by the prior knowledge, which is the brightness temperature from an unmanned aerial vehicle(UAV). Secondly, UAV flight which synchronization with satellite transit to obtain brightness temperature. Thirdly, the atmospheric effect between the UAV and the ground observations is corrected by the radiative transfer equation. Finally, the LST over the heterogenous land surface is validated by upscaled UAV LST. The results showed that the error between the UAV LST and the ground observations could be reduced from 3.2 K to about 0.5 K by calibrating the near-surface atmospheric effect. Besides, the validation of the LST satellite product by upscaling the UAV LST as “true values”, the results showed that the accuracy was about 1.17 K of Landsat product in heterogeneous surface, the bias was more observably with more big heterogeneity of surface which might cause by adjacent effect in Landsat products. This paper has achieved integrated airborne-space-ground observation and provided a better solution for satellite product validation on heterogeneous surfaces.