A useful approximation for the flat surface impulse response
Abstract
The flat surface impulse response (FSIR) is a very useful quantity in computing the mean return power for nearnadiroriented shortpulse radar altimeters. However, for very small antenna beamwidths and relatively large pointing angles, previous analytical descriptions become very difficult to compute accurately. An asymptotic approximation is developed to overcome these computational problems. Since accuracy is of key importance, a condition is developed under which this solution is within 2 percent of the exact answer. The asymptotic solution is shown to be in functional agreement with a conventional clutter power result and gives a 1.25dB correction to this formula to account properly for the antennapattern variation over the illuminated area.
 Publication:

IEEE Transactions on Antennas and Propagation
 Pub Date:
 June 1989
 DOI:
 10.1109/8.29363
 Bibcode:
 1989ITAP...37..764B
 Keywords:

 Antenna Radiation Patterns;
 Flat Surfaces;
 Pulse Radar;
 Radar Antennas;
 Approximation;
 Asymptotic Methods;
 Bessel Functions;
 Boresights;
 Communications and Radar