Calculation of the compression of microwave pulses by the ionosphere

Summary form only given. Two one-dimensional computational methods have been used for the investigation of the ionospheric compression of plane wave pulses. One method is a finite difference computer code which spatially integrates the dispersive effect of the electron density on the pulse over a specified path. The second method is a computationally efficient numerical convolution algorithm which is especially applicable to long initial pulses. The finite difference code is used to investigate the compression of relatively short pulses (< 50 ns) with different waveshapes and chirp profiles over various atmospheric paths. An 18-ns-long square pulse with an inverse square root chirp at 90 km produces an amplitude enhancement of 3.5 at 450 km for a perfectly vertical trajectory along an extended earth radius. In contrast, the convolution algorithm is used for the investigation of much longer chirped initial pulses. A properly chirped pulse with a bandwidth of one decade can be compressed temporally by a factor of about 40 into a nearly monopolar pulse.