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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Hydrology and Remote Sensing Laboratory » Research » Publications at this Location » Publication #408672
Research Project: From Field to Watershed: Enhancing Water Quality and Management in Agroecosystems through Remote Sensing, Ground Measurements, and Integrative Modeling

Location: Hydrology and Remote Sensing Laboratory

Title: Precision Soil Moisture Monitoring with Passive Microwave L-band UAS Mapping

Author
item KIM, K - University Of Virginia
item ZHU, Z - University Of Virginia
item ZHANG, R - University Of Virginia
item FANG, BIN - University Of Virginia
item Cosh, Michael
item Russ, Andrew - Andy
item DAI, E - Non ARS Employee
item ELSTON, J - Non ARS Employee
item STACHURA, M - Non ARS Employee
item GASIEWSKI, A - University Of Colorado
item LAKSHMI, V - University Of Virginia

Submitted to: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2024
Publication Date: 3/27/2024
Citation: Kim, K.Y., Zhu, Z., Zhang, R., Fang, B., Cosh, M.H., Russ, A.L., Dai, E., Elston, J., Stachura, M., Gasiewski, A., Lakshmi, V. 2024. Precision Soil Moisture Monitoring with Passive Microwave L-band UAS Mapping. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 17:7684-7694. https://doi.org/10.1109/JSTARS.2024.3382045.
DOI: https://doi.org/10.1109/JSTARS.2024.3382045

Interpretive Summary: Remote sensing of soil moisture from the ground and from aircraft and satellites has a long history. However, new technological advances have now made these sensing systems small enough to be flown on uncrewed aerial vehicles or drones. A new and novel drone sensing system was flown over a fallow corn field in Beltsville, Maryland, in the first independent study of its kind. The goal was to determine the accuracy and performance of the drone based microwave radiometer for estimating surface soil moisture. Comparisons to physical collection of soil moisture at the ground determined that the accuracy was similar to some satellite products, but there are still improvements which can be made to the algorithm to increase the accuracy. This will be of value to agricultural operators and land managers to enable better water use efficiency.

Technical Abstract: Although satellite-based soil moisture products are useful at regional and global scales, they do not meet the needs of users who require high resolution information for applications such as precision agriculture or catchment hydrologic modeling. The advent of uncrewed aerial systems (UAS) has opened new opportunities for bridging this need. We offer one of the very first validation studies on a dry-down event captured by a novel L-band radiometer onboard a Black Swift Technologies fixed-wing S2 drone. A fallow cornfield at the Beltsville Agricultural Research Center (BARC) was selected as a study area to validate volumetric soil moisture estimates in mid-April. By leveraging a comparable radiative transfer model to that of SMAP and SMOS derived products,brightness temperature retrievals from this sensor are shown to successfully capture a week of dry-down post-storm event, as validated by HydraGO probe estimates (calibrated with gravimetric samples) and a nearby weather station. However, with a reported spatially averaged bias of -0.107 m3/m3 (compared to calibrated, fitted moisture values) and an ubRMSE of 0.050 m3/m3 potential concerns remain regarding the calibration, vegetation and surface roughness corrections, and georeferencing. Nevertheless, given the potential of UAS for on-demand, high-resolution soil moisture retrievals, this study is critical for informing future applications and improvements in the field of passive microwave remote sensing.