Summary
Synthetic thinned aperture radiometry (STAR) is a method of radar in which the coherent product (correlation) of the signal from pairs of antennas is measured at different antenna-pair spacings (baselines).[1] These products yield sample points in the Fourier transform of the brightness temperature map of the scene, and the scene itself is reconstructed by inverting the sampled transform.[2] The reconstructed image includes all of the pixels in the entire field-of-view of the antennas.
The main advantage of the STAR architecture is that it requires no mechanical scanning of an antenna. Using a static antenna simplifies the antenna system dynamics and improves the time-bandwidth product of the radiometer. Furthermore, aperture thinning reduces the overall volume and mass of the antenna system. A disadvantage is the reduction of radiometric sensitivity (or increase in rms noise) of the image due to a decrease in signal-to-noise ratio for each measurement compared to a filled aperture. Pixel averaging is required for good radiometric sensitivity.
See also edit
- Beamforming
- Microwave Imaging Radiometer with Aperture Synthesis (MIRAS), an example of a spaceborne STAR
- Synthetic aperture radar
References edit
- ^ Piepmeier, J.R.; Pellerano, F.A.; Synthetic Thinned Aperture Radiometry (STAR) Technologies Enabling 10-km Soil Moisture Remote Sensing from Space, Proc. NASA Earth Science Technology Conference, (College Park, MD), 2002.
- ^ D. M. Le Vine, Synthetic aperture radiometer systems, IEEE Trans. Geosci. Remote Sensing, vol. 37, no. 12, pp. 2228-2236, 1999.