One solution for the receiver-to-target range, R R, is
where
R T = transmitter-to-target range,
L = baseline range,
? R = receiver look angle (in North coordinates).
This appendix develops a simplified approximation to (C.1) for the special case of a bistatic radar (1) using the direct range sum estimation method, Section 5.1, and (2) operating in a short-range over-the-shoulder geometry, where the range sum ( R T + R R) is slightly greater than the baseline L. Errors associated with this approximation are also developed. Specifically, the approximation generates a 10% error in the estimate of R R for 0 ? ? R ? 180 and L ? 0.82( R T + R R). Because the isorange contour eccentricity, e = L/(R T + R R), e > 0.82 for this special case.
Assume
where L >> ? L. Thus,
In the direct range sum estimation method, the time interval ?T rt between reception of the transmitted puise and reception of the target echo is measured. The range sum ( R T + R R) is then calculated by (5.2) as
or
Thus,
Combining (C.1) and (C.4) yields
Expanding and simplifying yields
From (C.6), c ?T rt/L << 1 and (C.8) becomes
In this case an estimate of the baseline length L is not needed. (An estimate of...
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