@InProceedings{SoaresShiVanzEngm:1992:EsBaSo,
               author = "Soares, Joao Vianei and Shi, Jiancheng and Vanzyl, Jakob and 
                         Engman, E. T",
          affiliation = "{} and Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, 
                         CA, United States and Goddard Space Flight Center, Code 974, 
                         Greenbelt, MD, United States",
                title = "Estimation of bare soil evaporation using multifrequency airborne 
                         SAR",
            booktitle = "Proceedings...",
                 year = "1992",
               editor = "Williamson, R. and Stein, T.",
                pages = "1747--1749",
         organization = "International Geoscience and Remote Sensing Symposium, 
                         (IGARSS'92).",
            publisher = "IEEE",
             keywords = "Atmospheric temperature, Digital storage, Evaporation, Geology, 
                         Moisture, Parameter estimation, Polarization, Radar, Radar 
                         imaging, Radar measurement, Remote sensing, Soil moisture, Soils, 
                         Space optics, Space-based radar, Surface roughness, Synthetic 
                         aperture radar, Agricultural areas, Energy flux model, Ground 
                         measurements, Infrared imagery, Polarization ratios, Spatial 
                         applications, Surface backscattering, Surface temperatures, Soil 
                         surveys.",
             abstract = "The optimal radar parameters to estimate soil moisture indicated 
                         by past research are C-band, H polarization at steep incidence 
                         angles (10 to 20 degrees). Although these parameters minimize 
                         effects of roughness and vegetation, the spatial application of 
                         space and airborne radar are limited to the near range of the 
                         swath. Aiming at the development of algorithms to broaden the 
                         range of useful data, an experiment was conducted with NASA/JPL 
                         airborne radar polarimeter (P, L and C Bands)in September 1989 in 
                         agricultural area near Fresno, California. There were two flights 
                         six days apart; ground measurements of soil moisture and surface 
                         roughness were taken on both flight dates in eight different 
                         fields. Based on first order surface backscattering models, a 
                         physically based algorithm for retrieval of soil moisture and 
                         surface roughness has been developed. It has been shown that the 
                         co-polarization ratio is sensitive to soil moisture but not to 
                         soil roughness at high incidence angles (38 to 60 degrees). The 
                         derived soil moisture was used to drive a two-layer heat and 
                         energy flux model in order to estimate evaporation from bare 
                         soils. The estimated values of evaporation for a two-week period 
                         are realistic. As the model incorporates time variations in both 
                         soil moisture and surface temperature, it could be used in 
                         conjunction with values of those parameters periodically estimated 
                         using SAR and infrared imagery, providing estimates of bare soil 
                         evaporation.",
  conference-location = "Houston, USA",
      conference-year = "26-29 May 1992",
                 isbn = "0780301382",
                label = "7048",
             language = "en",
           targetfile = "1992_soares.pdf",
        urlaccessdate = "2024, Dec. 11"
}