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Advancing NASA’s AirMOSS P-Band Radar Root Zone Soil Moisture Retrieval Algorithm via Incorporation of Richards’ Equation
- Source :
- Remote Sensing; Volume 9; Issue 1; Pages: 17, Remote Sensing, Vol 9, Iss 1, p 17 (2016), Plants, Soils, and Climate Faculty Publications
- Publication Year :
- 2016
- Publisher :
- Multidisciplinary Digital Publishing Institute, 2016.
-
Abstract
- P-band radar remote sensing applied during the Airborne Microwave Observatory of Subcanopy and Subsurface (AirMOSS) mission has shown great potential for estimation of root zone soil moisture. When retrieving the soil moisture profile (SMP) from P-band radar observations, a mathematical function describing the vertical moisture distribution is required. Because only a limited number of observations are available, the number of free parameters of the mathematical model must not exceed the number of observed data. For this reason, an empirical quadratic function (second order polynomial) is currently applied in the AirMOSS inversion algorithm to retrieve the SMP. The three free parameters of the polynomial are retrieved for each AirMOSS pixel using three backscatter observations (i.e., one frequency at three polarizations of Horizontal-Horizontal, Vertical-Vertical and Horizontal-Vertical). In this paper, a more realistic, physically-based SMP model containing three free parameters is derived, based on a solution to Richards’ equation for unsaturated flow in soils. Evaluation of the new SMP model based on both numerical simulations and measured data revealed that it exhibits greater flexibility for fitting measured and simulated SMPs than the currently applied polynomial. It is also demonstrated that the new SMP model can be reduced to a second order polynomial at the expense of fitting accuracy.
- Subjects :
- Richards’ equation
010504 meteorology & atmospheric sciences
Science
0208 environmental biotechnology
02 engineering and technology
01 natural sciences
Airborne Microwave Observatory of Subcanopy and Subsurface (AirMOSS)
law.invention
root zone
soil moisture profile
law
Radar
Water content
Physics::Atmospheric and Oceanic Physics
0105 earth and related environmental sciences
Remote sensing
Mathematics
Pixel
Plant Sciences
Quadratic function
020801 environmental engineering
radar backscatter
P-band remote sensing
Soil water
Other Plant Sciences
General Earth and Planetary Sciences
Richards equation
Microwave
Free parameter
Subjects
Details
- Language :
- English
- ISSN :
- 20724292
- Database :
- OpenAIRE
- Journal :
- Remote Sensing; Volume 9; Issue 1; Pages: 17
- Accession number :
- edsair.doi.dedup.....e397da8d6cbd51c077b6f433619c628f
- Full Text :
- https://doi.org/10.3390/rs9010017