L-Band Soil Moisture Mapping Using UAS For Validation And Calibration Of SMAP
Gasiewski, Albin J 1 ; Stachura, Maciej 2 ; Elston, Jack 3 ; McIntyre, Eric M 4 ;Dai, Eryan 5
5 Presenting Author
1 Dept. of ECEE, University of Colorado, Boulder, CO,
2 Dept. of ECEE, University of Colorado, Boulder, CO, Black Swift Technologies LLC, Boulder, CO
3 Dept. of ECEE, University of Colorado, Boulder, CO, Black Swift Technologies LLC, Boulder, CO
4 Dept. of ECEE, University of Colorado, Boulder, CO,
5 Dept. of ECEE, University of Colorado, Boulder, CO,
Due to long electrical wavelengths and aperture size limitations the scaling of passive microwave remote sensing of soil moisture from spaceborne low-resolution applications to high-resolution applications suitable for precision agriculture requires use of low flying aircraft. This poster summarizes the project to develop a commercial Unmanned Aircraft System (UAS) hosting a precision microwave radiometer for mapping of soil moisture in high-value shallow root-zone crops. The project is based on the use of the Tempest electric-powered UAS and a compact digital L-band (1400-1427 MHz) passive microwave radiometer developed specifically for extremely small and lightweight aerial platforms or man-portable, tractor, or tower-based applications. Notable in this combination are a highly integrated UAS/radiometer antenna design and use of both the upwelling emitted signal from the surface and downwelling cold space signal for precise calibration using a lobe-correlating radiometer architecture. The system achieves a spatial resolution comparable to the altitude of the UAS above the ground while referencing upwelling measurements to the constant and well-known background temperature of cold space. The radiometer incorporates digital sampling and radio frequency interference mitigation along with infrared, near-infrared, and visible (red) sensors for surface temperature and vegetation biomass correction. This NASA-sponsored project is being developed both for commercial application in cropland water management, L-band satellite validation, and estuarian plume studies.