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Synthetic-aperture radar determines the 3D reflectivity from measured SAR data. It is basically a spectrum estimation, because for a specific cell of an image, the complex-value SAR measurements of the SAR image stack are a sampled version of the Fourier transform of reflectivity in elevation direction, but the Fourier transform is irregular. [18]
Synthetic aperture radar (SAR) allow for an angular resolution beyond real beamwidth by moving the aperture over the target, and adding the echoes coherently. Architecture: The field of view is scanned with a highly directive frequency-orthogonal (slotted waveguide), spatially orthogonal (switched beamforming networks), or time-orthogonal beams.
The associated resolution loss from sharing the synthetic aperture among different swaths is compensated by collecting radar echoes with multiple displaced azimuth apertures. A possible drawback of multichannel ScanSAR or TOPS approaches is the rather high Doppler centroid, [ 9 ] which is one of the most important parameters need to be ...
Synthetic-aperture radar (SAR) is a form of radar which moves a real aperture or antenna through a series of positions along the objects to provide distinctive long-term coherent-signal variations. This can be used to obtain higher resolution.
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.
The radar system required about 80 hours to collect one complete aperture of high-resolution, fully polarimetric data. Its peak power was at 500 kW with a pulse repetition frequency of 40 Hz, and the average transmitted power was about 20 mW. Creating the radar image required the railSAR to limit the Fourier processing to very small patches ...
The history of synthetic-aperture radar begins in 1951, with the invention of the technology by mathematician Carl A. Wiley, and its development in the following decade. Initially developed for military use, the technology has since been applied in the field of planetary science .
AN/AWG-14 is the final member of the lineage of this radar family, and it is a fully digitized upgrade of the AWG series [11] incorporating AN/APQ-120. The open architecture and modular design enable AWG-14 to accommodate different radars, such as AN/APG-65, AN/APG-66, AN/APG-76, Elta EL/M-2011/2021 and EL/M-2032.