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.
Original source: https://en.wikipedia.org/wiki/Synthetically thinned aperture radar.
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