|Levine, D - NASA|
|Haken, M - NASA|
Submitted to: IEEE Transactions on Geoscience and Remote Sensing
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 20, 2007
Publication Date: November 1, 2007
Citation: LeVine, D., Jackson, T.J., Haken, M. 2007. Initial images of the synthetic aperture radiometer 2D-STAR. IEEE Transactions on Geoscience and Remote Sensing. 45:3623-3632. Interpretive Summary: The first ever soil moisture analyses using two dimensional synthetic aperture radiometry were conducted. Passive microwave remote sensing at long wavelengths offers the potential for monitoring global soil moisture, however, long wavelengths require large antennas in orbit and this requirement has limited the resolution obtainable from space. A next generation synthetic aperture radiometer has been developed to demonstrate the potential of aperture synthesis in two dimensions for remote sensing applications such as monitoring soil moisture. This instrument, called 2D-STAR, represents a next step in the development of the technology. It also represents the radiometer technology employed in the Soil Moisture and Ocean Salinity Mission (SMOS) being developed by the European Space Agency. In the summer of 2003 it participated in a soil moisture field campaign flying research sites in Alabama, Georgia and Oklahoma and demonstrated that a soil moisture response could be established. This instrument represents the next step in this technology, extending synthesis to two dimensions and to dual polarization. Synthesis in two dimensions offers the promise of new remote sensing options such as obtaining data over a wide range of incidence angle (and azimuth) and of providing options for advanced retrieval algorithms. These results will contribute to the implementation of operational satellite retrievals and adaptation of the products in a wider range of applications in agriculture, hydrology and climate studies.
Technical Abstract: Initial results obtained using a new synthetic aperture radiometer, 2D-STAR, a dual polarized, L-band radiometer that employs aperture synthesis in two dimensions are presented and analyzed. This airborne instrument is the natural evolution of a previous design that employed employs aperture synthesis only in the across- track dimension, and represents a further step in the development of aperture synthesis for remote sensing applications. A description of the instrument and initial results in the form of first images and a preliminary comparison with changes in soil moisture during soil moisture experiments conducted in Alabama, Georgia, and Oklahoma in 2003 are presented here. 2D-STAR represents the next step in this technology, extending synthesis to two dimensions and to dual polarization. Synthesis in two dimensions offers the promise of new remote sensing options such as obtaining data. It also represents the radiometer technology employed in the Soil Moisture and Ocean Salinity Mission (SMOS) being developed by the European Space Agency.