Bistatic Surface Clutter Resolution Area at Small Grazing Angles
Interim rept. Oct 1981-Jan 1982
MITRE CORP BEDFORD MA
Pagination or Media Count:
Approximate expressions for the main beam bistatic surface clutter cell area in the resolution time-limited case are determined as a function of the bistatic scattering angle for a transmitter and receiver which subtend small grazing angles at the clutter cell. The bistatic angle is the angle subtended at the clutter cell by the lines joining it to the transmitter and receiver. The Shape of the clutter cell is a function of the transmitter and receiver azimuthal beamwidths, the receiver resolution time, and the time-delay difference between the clutter return and the direct signal from the transmitter to receiver. For time-delay differences much greater than the receiver resolution time, the cell shape is a parallel-ogram. For small time-delay differences, the cell shape is approximately trapezoidal or triangular at small bistatic angles and rhomboidal or hexagonal at large bistatic angles. Approximate expressions for the clutter cell area are derived for arbitrary time-delay differences. The clutter cell area increases with increasing bistatic angle and is proportional to the squared of one-half the bistatic angle for all angles except those approaching 180 degrees. The cell area is typically more than 30 dB larger in the forward-scattered direction than in the backscattered direction.
- Active and Passive Radar Detection and Equipment
- Radiofrequency Wave Propagation