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In those situations, it is useful to use a related quantity called the normalized radar cross-section (NRCS), also known as differential scattering coefficient or radar backscatter coefficient, denoted σ 0 or σ 0 ("sigma nought"), which is the average radar cross-section of a set of objects per unit area:
Optical cross section of a flat mirror with a given reflectivity at a particular wavelength () can be expressed by the formula = Where is the cross sectional diameter of the beam. Note that the direction of the light has to be perpendicular to the mirror surface for this formula to be valid, else the return from the mirror would no longer go ...
For basic considerations of the strength of a signal returned by a given target, the radar equation models the target as a single point in space with a given radar cross-section (RCS). The RCS is difficult to estimate except for the most basic cases, like a perpendicular surface or a sphere.
The cross-section is the minimum apparent surface area observed in the direction of the radar that must be detectable.. Radar cross section changes with aspect angle. Cross section for anything except a perfect sphere depends upon the aspect angle, which how far the reflector is rotated with respect to the radar pulse.
When it is exactly zero the radar is a monostatic radar, when it is close to zero the radar is pseudo-monostatic, and when it is close to 180 degrees the radar is a forward scatter radar. Elsewhere, the radar is simply described as a bistatic radar. The bistatic angle is an important factor in determining the radar cross section of the target.
One open-literature study combined several pieces of radar information: cross-section, range, and Doppler measurements. [25] A 1997 Defense Department report mentions "Air Force and Navy combat identification efforts focus on non-cooperative target recognition technologies, including inverse synthetic aperture radar imaging, jet engine ...
σ = radar cross section, or scattering coefficient, of the target; F = pattern propagation factor; R t = distance from the transmitter to the target; R r = distance from the target to the receiver. In the common case where the transmitter and the receiver are at the same location, R t = R r and the term R t ² R r ² can be replaced by R 4 ...
The shooting and bouncing rays (SBR) method in computational electromagnetics was first developed for computation of radar cross section (RCS). [1] Since then, the method has been generalized to be used also for installed antenna performance. The SBR method is an approximate method applied to high frequencies.