Abstract: Transmissions from a moving, vehicle-mounted transmitter to a remote station are pre-compensated at the transmitter for doppler shift by measuring the doppler shift of signals from the remote station and compensating by the use of a digital multiplier the frequency of transmissions to the remote station in the opposite sense and in an amount equal to the ratio of the nominal transmission to reception frequencies times the measured doppler shift. Application to full and half duplex radios and provisions for frequency shift keying systems are disclosed.

Abstract: An apparatus for presenting radar target return signals having a spectrum of frequency components in a binaural audible form whereby an operator can detect a target or a plurality of simultaneous unresolved targets, determine the direction of each target relative to the radar antenna axis, and identify the type and motion of each target using only his auditory sense. The apparatus utilizes a filter to ensure that all frequency components of the return signal from each target have the same relative time of arrival at the two ears, thus binaurally localizing each target.

Abstract: A transmitter for communicating binary data by minimum shift keying (MSK) wherein control of the radiated spectrum of the transmitted signal is achieved by controlling the rate of switching between mark and space frequency signals such that the MSK switch acts as an equivalent of a low pass filter.