Synthetic aperture

J.Seydel, Ultrasonic Synthetic-aperture Focusing Techniques in NDT , Research Techniques in NDT, London, 1983, v.6. 

Keywords radar radar imaging tomography high resolution synthetic aperture radar interferometry polarimetry Radon transform projection slice theorem backprojection. 

These examples are illustrative of the potential of synthetic aperture imaging. However, it should be appreciated that the challenge is to extract useful information on the desired targets from such imagery. 

Carrara, W.G., Goodman, R.S. and Majewski, R.M., Spotlight Synthetic Aperture Radar Signal Processing Algorithms, Artech House, 1995. 

Gjessing, D.T. and Saebboe, J., Bistatic matched illumination radar involving synthetic aperture and synthetic pulse for signal to clutter enhancement and target characterization , Proc. 2001 CIE International Conference on Radar, Beijing, pp 20-24, 15-18 October 2001. 

M Soumekh, Reconnaissance with ultra wideband UHF synthetic aperture radar , in IEEE Signal Proc. Mag.. Vol. 12, No. 4, pp. 21-40, July 1995. 

C. Jakowatz, D. Wahl, P. Eichel, D. Ghiglia, P. Thompson. Spotlight-Mode Synthetic Aperture Radar A Signal Processing Approach, Kluwer Academic Publishers, 1996. 

In order to improve volume efficiency and reduce payload weight for earth-orbital remote-sensing applications, low-mass membrane-based synthetic aperture radar array concepts are being developed. One such system is an inflatable deployable SAR consisting of thin fabrics or membranes that are deployed for L-band operation with dual polarisation. The entire assembly is flexible before employment and is rolled up onto the spacecraft bus. The antenna comprises three membranes positioned vertically over one another the ground plane, the radiation patch, and the microstrip transmission line membranes74. 

Ocean surface level TOPEX/Poseidon, Jason-1, ERS-2, ENVISAT. ENVISAT is equipped with synthetic aperture radar ASAR, altimeter RA-2, microwave radiometer MWR, interferometer MIPAS, system of positioning DORIS, and system to record ozone layer characteristics GOMOS. 

Wind field characteristics Seawinds/QuickSCAT, ERS-2, Seawinds/ADEOS-2, SSM/I. Spaceborne system ERS-2 is equipped with scatterometer WS, synthetic aperture radar SAR, microwave radiometer MWR, altimeter RA, scanning radiometer ATSR, and the system GOME to measure ozone. 

An active system that scans the transmitter along with the receiver, as is done in synthetic aperture (SAR and holographic) imaging systems has twice the phase variation across the aperture compared with a passive system (or active systems with a fixed source or sources). This doubling of the phase shift results in a factor of two improvement in the image resolution (one half the spot size) for... 

M. Soumekh, A system model and inversion for synthetic aperture radar imaging, IEEE Transactions on Image Processing, vol. 1, PP- 64—76, 1992. 

The interferometric imaging method of synthetic aperture image reconstruction, described in detail in Section 4, detects the THz electric field at multiple locations and then uses the correlated phase and amplitude of the electric field from selected pairs of detectors [72],... 

In the absence of a kilopixel THz camera, one needs to play tricks to increase the imaging speed and pixel count of images. One method is to convert THz to another frequency range (e.g., visible) for which imaging cameras are readily available. Another method is a synthetic aperture imaging/interferometric imaging approach [72],... 

Hess, L. L, J. M. Melack, S. Filoso, and Y. Wang. 1995. "Delineation of inundated area and vegetation along the Amazon floodplain with the SIR-C synthetic aperture radar." IEEE Transactions in CeoscietKe and Remote Sensing 33 896-904. 

The Pioneer Venus mission provided the first radar imaging and altimetry of Venus surface from synthetic aperture radar on an orbiting spacecraft. Subsequently, the Venera 15 and 16 orbiters also carried out radar imaging and altimetry of part of Venus northern hemisphere. Orbital spacecraft radar observations of Venus culminated with the very successful Magellan mission in the early 1990s. 

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