| Paper: | WE-A2.1 |
| Session: | Land Applications of Radiometry II |
| Time: | Wednesday, March 28, 10:40 - 11:00 |
| Presentation: |
Oral
|
| Topic: |
Soil moisture, soil state and vegetation: |
| Title: |
P-band Passive Microwave Sensing of Soil Moisture: Preliminary Results |
| Authors: |
Nan Ye; Monash University | | |
| | Jeffrey Walker; Monash University | | |
| | Nithyapriya Boopathi; India Institute of Technology Bombay | | |
| | Xiaoling Wu; Monash University | | |
| | In-Young Yeo; University of Newcastle | | |
| | Thomas Jackson; USDA ARS Hydrology and Remote Sensing Laboratory | | |
| | Yann Kerr; Centre National d’Etudes Spatiales | | |
| | Edward Kim; NASA Goddard Space Flight Center | | |
| | Andrew McGrath; Airborne Research Australia | | |
| | Yalamanchili Rao; India Institute of Technology Bombay | | |
| Abstract: |
Soil moisture plays a key role in global water, energy, and carbon cycles. Its temporal and spatial distribution is also critical for hydrological, meteorological, and agricultural applications. Current soil moisture dedicated missions, SMAP of NASA and SMOS of ESA, can only provide moisture information on the top 5 cm layer of soil using current passive microwave remote sensing technology at L-band (21 cm; 1.4 GHz). To better understand deeper layer soil moisture that more closely relates to crop and pasture growth rate, we are demonstrating a new state-of-the-art satellite concept for the top 10-15 cm layer of soil moisture retrieval, using airborne and tower-based passive microwave sensing observations at P-band. Due to its longer wavelength, the P-band radiometry technique is also expected to produce more accurate estimates of soil moisture due to its reduced sensitivity to surface roughness and vegetation than L-band. Consequently, soil moisture data would also be available at some of the more densely vegetated areas that currently suffer at L-band. A dual-polarized (horizontally and vertically) multi-beam P-band radiometer (40 cm; 742-752 MHz) has been used together with an L-band radiometer during a short-term airborne field experiment in Jan. 2017 and a long-term continuous tower-based experiment since Oct. 2017. Intensive and regular soil moisture, vegetation water content, and surface roughness sampling were conducted for development of the soil moisture retrievals. The preliminary results show i) high sensitivity of P-band brightness temperature to soil moisture with a similar spatial pattern to L-band; and ii) a stronger angular relationship than L-band. Details of the airborne and tower-based field experiments will be presented together with some early results, comparing P-band and L-band passive microwave observations. |
