Field-Scale Soil Moisture Retrieval using PALS Airborne Microwave Radiometer during SMAPVEX16
Abstract
Soil moisture is a critical parameter for many aspects in agricultural activity. Remote sensing enables monitoring of soil moisture over large areas efficiently. Over the years, studies have shown that the most accurate soil moisture measurement needs low frequency (1.4 GHz) microwave radiometer. However, the drawback of the measurement is that it requires a relatively large antenna aperture; most of the agricultural application need a minimum of field-scale resolution for resolving the soil moisture for individual fields. This means the soil moisture measurement should have a resolution ranging from tens of meters to hundreds of meters depending on the layout of the cultivated area.
The Soil Moisture Active Passive (SMAP) mission conducted a field experiment in agricultural areas in 2016 for the validation of the SMAP soil moisture product. The SMAP Validation Experiment 2016 (SMAPVEX16) deployed the airborne Passive Active L-band System (PALS) and ground teams to instrumented validation sites in Iowa and Manitoba in May-June and again in July-August to capture the full range of crop conditions. PALS mapped each 30x40 km site (compatible with the SMAP resolution) 12 times at 1.5-km resolution, and additionally, covered 400km2 at the field scale using 600-m resolution, as the typical field size at the sites were 800x800 m. The measurements demonstrated the capability of producing field-scale soil moisture in a systematic manner using an airborne instrument. The retrieved soil moistures had the fidelity to distinguish field to field differences and the algorithm was able to account for the features of different crop types. The measurements provide a model for future larger agricultural deployments for further investigating water related questions.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H41P1942C
- Keywords:
-
- 1816 Estimation and forecasting;
- HYDROLOGY;
- 1836 Hydrological cycles and budgets;
- HYDROLOGY;
- 1847 Modeling;
- HYDROLOGY;
- 1855 Remote sensing;
- HYDROLOGY