The "Myth" of the Minimum SAR Antenna Area Constraint
A design constraint traceable to the early days of spaceborne Synthetic Aperture Radar (SAR) is known as teh minimum antenna area constraint for SAR.
SAR↗
Engineering topics
Curlander, J.
Publications and source records attributed to Curlander, J..
The "Myth" of the Minimum SAR Antenna Area Constraint
A design constraint traceable to the early days of spaceborne Synthetic Aperture Radar (SAR) is known as the minimum antenna area constraint for SAR. It specifies, as the name suggests, a minimum area for SAR antennas, to optimize performance.
design↗
The "Myth" of the Minimum SAR Antenna Area Constraint
A design constraint traceable ot the early days of spaceborne Synthetic Aperture Radar (SAR) is known as the minimum antenna area constraint for SAR. In this paper, it is confirmed that this constraint strictly applies only to the case where both the best possible resolution and the widest possible swath are the design goals. SAR antennas with area smaller than the constraint allows are shown to be possible, have been used on spaceborne SAR missions in the past, and should permit further, lower-cost SAR mission in the future.
Freeman, A.↗
Refinement of Magellan radiometric correction using range centroid estimation
The Magellan (MGN) synthetic aperture radar (SAR) processing radiometric compensation algorithm is described, and the effective pointing error caused by the terrain is examined. It is shown how the range centroid can be computed from spacecraft ancillary data with an accurate topographic model. In cases where such data are not available, a technique is presented to estimate the range centroid from the coherent radar echoes. This technique is demonstrated using MGN SAR data.
Cheng, T.↗
Automated tracking of arctic ice floes in multitemporal SAR imagery
A discussion is presented of two algorithms to perform shape matching on the boundaries of ice floes in SAR (synthetic aperture radar) images in order to produce an ice motion map. The algorithms match a shape descriptor known as the psi-s curve. The first algorithm uses normalized correlation to match the psi-s curves, while the second uses dynamic programming to compute an elastic match that better accommodates deformation of the ice floe boundary.
Mcconnell, R.↗
Construction and analysis of simulated Venera and Magellan images of Venus
The 1-3 km resolution Venera 15 and 16 images of Venus and the expected 120-300 m resolution Magellan mission image data are presently simulated through a digital processing of Seasat radar images covering a desert dune complex in the Gran Desierto of Sonora, accreted terranes in the central interior of Alaska, and the Appalachian Valley and Ridge Province. The simulations suggest that the nature and extent of terrain modification on Venus by such exogenic processes as atmosphere-surface weathering, erosion, and deposition, will remain uncertain, since the length scale of features indicative of such processes may be too small to be discerned from Venera data; Magellan data may provide this critical fine-scale morphological data, however, and thereby allow the testing of the two competing resurfacing scenarios.
Arvidson, R. E.↗
Performance evaluation of the JPL interim digital SAR processor
The performance of the Interim Digital SAR Processor (IDP) was evaluated. The IDP processor was originally developed for experimental processing of digital SEASAT SAR data. One phase of the system upgrade which features parallel processing in three peripheral array processors, automated estimation for Doppler parameters, and unsupervised image pixel location determination and registration was executed. The method to compensate for the target range curvature effect was improved. A four point interpolation scheme is implemented to replace the nearest neighbor scheme used in the original IDP. The processor still maintains its fast throughput speed. The current performance and capability of the processing modes now available on the IDP system are updated.
Wu, C.↗
Shear zone ice deformation using supervised analysis of Seasat data
Spacecraft and aircraft Synthetic-Aperture Radar (SAR) images are commonly used to compute sea ice conditions including especially the drift velocities of ice features. Recent developments, described in this paper, in computer-aided analysis and in digital image processing have extended the analysis speed and accuracy of registration to the point that ice deformation can be examined on the geophysically important scales of about 100 m over tens of kilometers between two 'snapshots.' Examples are shown for the ice motion and rotation in the shear zone near the Alaska coast from Seasat data in 1978.
Carsey, F.↗
Doppler parameter estimation techniques for spaceborne SAR with applications to ocean current measurement
The problems of Doppler parameter estimation in the processing of spaceborne synthetic aperture radar (SAR) data are examined. The phase history of a target can be approximated by a linear FM signal with two parameters: the Doppler centroid and the Doppler frequency rate. Two methods to estimate these parameters automatically from the radar echo are presented. The accuracies of these methods were evaluated using the SEASAT SAR data. It is shown that the method for Doppler centroid determination may be applicable in the measurement of ocean current velocities. The concept behind this technique is presented and the accuracies of the measurements required are examined. Some preliminary results of testing this technique with the SEASAT data are presented.
Li, F.↗