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High-Resolution Measurements of Scattering in Wheat Canopies Implications for Crop Parameter Retrieval

By K. Morrison, C. S. M. Brown, S. Quegan, J. C. Bennett and G. Cookmartin

Abstract

Polarimetric X- and C-band measurements by the University of Sheffield ground-based synthetic aperture radar(GB-SAR)indoor system provide three-dimensional images of the scattering processes in wheat canopies, at resolutions of around a wavelength (3–6 cm). The scattering shows a pronounced layered structure, with strong returns from the soil and the flag leaves, and in some cases a second leaf layer. Differential attenuation at horizontal (H) and vertical (V) polarization, due to the predominantly vertical structure of the wheat stems, gives rise to marked effects. At both C and X bands, direct return from the canopy exceeds the soil return at large incidence angles for VV polarization, but is comparable to or less than the soil return in all other cases. At HV, the apparent ground return is probably due to a double-bounce mechanism, and volume scattering is never the dominant term. Direct sensing of the crop canopy is most effective at X band, VV, and large incidence angles, under which conditions the return is dominated by the flag leaf layer. Field measurements with the outdoor GB-SAR system suggest, however, that for sensitivity to biomass and reduced susceptibility to disturbances by rainfall, a two-channel C-band system operating at a medium range of incidence angles is preferred

Publisher: IEEE; 1999
Year: 2006
OAI identifier: oai:dspace.lib.cranfield.ac.uk:1826/1052
Provided by: Cranfield CERES
Journal:

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Citations

  1. (1987). (M’97) received the B.S. degree in physics with astrophysics from the University of Leicester,
  2. (2001). A backscatter model for wheat canopies. Comparison withC-bandmultiparameterscatterometermeasurements,” in
  3. (1976). Bennett was a recipient of the Best Paper Award and the Best Applications Paper Award for a paper published in the doi
  4. (1995). Brown received the M.Eng. degree in electrical and electronic engineering from the University of Newcastle,
  5. (1981). Cookmartin received the B.A. degree in electrical sciences from Trinity College,
  6. (1991). Crop parameter estimation from ground-based X-band (3 cm wave) radar backscattering data,” Remote Sens. doi
  7. (1996). Developmentofa ground-based, polarimetric synthetic aperture radar,” in doi
  8. (1985). Effet de la polarization d’une onde electromagnetique dans l’attenuation de l’onde dans un couvert vegetal,” in
  9. (1999). Experimental and model investigationonradarclassificationcapability,”IEEETrans.Geosci.Remote Sensing, doi
  10. (1990). Ground-based X-band (3 cm wave) radar backscattering of agricultural crops. II. Wheat, barley and oats: The impact of canopy structure,” Remote Sens. doi
  11. (1995). Guerriero,“A fullypolarimetric multiple scattering model for crops,” Remote Sens. doi
  12. (1999). High-resolution microwave polarimetric imaging of small trees,” doi
  13. (1993). Interpreting ERS SAR signatures of agricultural crops in Flevoland, doi
  14. (2000). Modeling microwave interactions with crops and comparison with ERS-2 doi
  15. (1976). Monitoring wheat growth with radar,” Photogrammetric Eng. Remote Sens.,
  16. (1993). Multitemporal, multi-frequencyradarmeasurementsofagriculturalcropsduringtheAgriscatt-88 campaign in
  17. On the relationships between radar backscattering coefficient and vegetation canopy characteristics,” in
  18. (1983). Relations entre le coefficient de retrodiffusion radar et les caracteristiques d’un couvert vegetal: Considerations sur l’effet de la structure,” in
  19. (2001). Retrieval of Bio- and Geo-Physical Parameters from SAR Data for Land Applications”, doi
  20. (1981). Scatterometer measurements on crop and soil surfaces,” in
  21. (2003). She is currently with the Advanced Technology Centre, BAE Systems, Chelmsford, U.K., where her primary research interest is retrieval of information from SAR imagery and the development of SAR techniques for a variety of different land applications.1610
  22. (2001). she was a Research Associate with the University of Sheffield, working on the retrieval of biophysical parameters from wheat canopies using high-resolution ground-based SAR systems.
  23. (1997). The potential of multifrequency polarimetric SAR in assessing agricultural and arboreous biomass,” doi
  24. (2000). The UK NERC fully portable polarimetric ground-based synthetic aperture radar (GB-SAR),” in doi
  25. (2001). Three-dimensional X-band SAR imaging of a small conifer tree,” doi
  26. (1987). to 1994, he was with the British Antarctic Survey, Cambridge, U.K., carrying out research in space plasma physics. Between
  27. (1978). Vegetation modeled as a water cloud,” doi
  28. (2000). Wheat scattering mechanisms observed in near-field imagery compared with results from a radiative transfer model,” in doi

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