Radar imaging

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

Pasmurov, A. Ya. and Zinoviev, Yu. S., Radar Imaging and Tomography, to be published by Peter Peregrinus, Stevenage, 2005. 

This type of signal detection analysis was advanced during World War II for the monitoring of radar images where it was necessary for radar receiver operators to make judgments on whether a blip was due to enemy or friendly objects, or just noise. Consequently the analysis is known as Receiver Operator Characteristics or ROC. 

FIGURE 9.14 A radar image of the surface of Verms. Although the rocks are very hot, the partial pressure of carbon dioxide in the atmosphere is so great that carbonates may be abundant. 

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

D. L. McMakin, D. M. Sheen, J. W. Griffin, and W. M. Lechelt, Extremely high-frequency holographic radar imaging of personnel and mail, Proceedings ofSPIE, vol. 6201, 2006. 

Slade M., Butler B., and Muhleman D. (1992) Mercury radar imaging evidence for polar ice. Science 258, 635-640. 

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. 

June 7, 1983 Venera 16, orbiter Oct. 14, 1983, orbit entry. Radar imaging from N. pole to 30° N, radar altimetry, and atm. spectroscopy expts. (Barsukov et al., 1992 Bougher et al., 1997)... 

Slick radar image modelling with an extended VIERS-1 wave spectrum... 

Radar is a valuable sensor for the maritime environment. It can provide information about a great variety of features and processes, such as wind, waves, currents, ships, bathymetry and natural and man-made slicks. When oil spills are at issue, the pertinent questions are location, extent, thickness, type and age, and the prediction of these. Some of these questions may be answered on the basis of imaging radar data. At the same time, also natural slicks alter the radar properties of the sea surface, thereby complicating the interpretation of radar imagery when the interest is aimed at other features. Therefore, it is necessary to understand the characteristics of slicks, both man-made and natural, in radar images. 

This contribution presents some results of research into the modelling of the radar imaging of slicks, which are here assumed to be in the form of surface films. The research was aimed at assembling a numerical, physics-based model to calculate the radar image of a slick on the sea surface, and at improving the consistency of the elements of this model. The elements of the model are ... 

In what follows, the above elements will successively be discussed. In section 2, the VIERS-1 equilibrium spectrum will be briefly described, followed by a discussion of the extensions that have been implemented in order to be able to better use it for the present purpose of slick modelling. In section 3, an attempt is made to derive relaxation rates from this spectrum, and the form of the net restoring source term when out of equilibrium is established. In section 4, the radar image modelling will be discussed. Section 5, finally, discusses and summarises the results. 

The finite relaxation rate smoothes the edges of the slick in the modelled radar image. For strong damping, this effect is stronger on the leeward side of the slick than on the windward side. This is due to the factor N/Neq in the source term producing smaller relaxation rates at lower absolute spectral levels. Because this form of the source term derives from the analysis of section 3, this should be a realistic effect. (In reality, one may expect additional effects from the wind action on the slick distribution on the water surface that may also give rise to different radar profiles for the leeward and windward sides.) Because of this, the apparent size of the slick is increased. For example, if one would take as the criterion for the extent of... 

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