Abstract: Antenna alignment in troposcatter systems is accomplished by: (1) nutating the antenna receiver beam with a sinusoidal nutation signal to induce envelope modulation on the received signal; (2) crosscorrelating the envelope of the received signal with the nutating signal; and, (3) aligning the average angle of the antenna receiver beam into the position where the crosscorrelation goes to zero.

Abstract: Precise azimuthal alignment of troposcatter system antennas is achieved by centering on the great circle, the combined pattern of intercepting beams from two troposcatter antennas. The combined antenna pattern is determined to be centered on and symmetric about the great circle when the Doppler spectrum on a received signal is symmetric about zero Doppler shift. The alignment procedure comprehends antenna manipulation, initially with both beams focussed and subsequently with one beam defocussed, until the desired Doppler spectrum condition is obtained. The requisite Doppler information is derived and processed by novel cross correlation techniques and data processing procedures.