Evaluating soil moisture monitoring systems for remote sensing calibration and validation

Authors: Cosh, Michael

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary: N/A

Technical Abstract: There is an ever increasing number of satellite platforms collecting information for soil moisture estimation. These platforms have varying temporal, spatial, and vertical resolutions. The resulting observational and modeled products require in situ resources for ground based calibration and validation. But these resources are not fully deployed across a variety of landscapes and there is a lack of high resolution networks to validate the higher resolution products. Current modeled products are being produced at a resolution as fine as 30 m on a daily time scale. Other satellite only based products are approaching 1km in scale. These scales are approaching management scales for forestry and agriculture, but few study sites are available for providing ground truth to these products. A review of current resources will be presented and lessons learned from prior cal/val programs including the Advanced Microwave Scanning Radiometer (AMSR-E), the Soil Moisture Ocean Salinity (SMOS) mission, and the Soil Moisture Active Passive (SMAP) mission. Mission metrics for these products ranged from 0.06-0.04 m3/m3 depending on the product type. Initial efforts for calibration and validation included footprint scale soil moisture networks designed to capture a single satellite footprint scale estimate which would be maintained for several years to provide a continuous point of comparison. This strategy was complemented by intensive field campaigns over more highly monitored areas with intensive observation periods related to aircraft overflights. These evolved into multi-location and multi-period campaigns to maximize diversity of datasets and resources. In addition, new network resources have been developed including long term monitoring sites, including sites optimized for calibration and validation. There are still challenges in monitoring, including how to properly account for agricultural domains with active land management. Future missions that will be informed by these experiences will the NASA-ISRO Synthetic Aperture Radar Mission (NISAR) and ESA Copernicus Imaging Microwave Radiometer (CMIR).