Optimum transionospheric pulse transmission

The synthesis of optimum signals for transionospheric propagation along a vertical path is considered in this paper. It is seen that optimum band-limited signals having complicated amplitude and frequency modulation results in good pulse compression over a wide range of ionospheric conditions. The transmission of linearly swept carrier (chirp) pulses having rectangular and Gaussian envelopes is then considered with the result that appreciable compression is also seen to occur for these signals. Finally, an example is given of the statistical effects that variations in the total ionospheric electron content have on enhanced pulse transmission.