Abstract: The invention provides a radar system capable of transmitting data communications concurrently with and on a non-interfering basis with the normal radar functions. A continuous-wave carrier frequency is generated and transmitted to perform the normal radar function such as the processing of doppler data. For data communication purposes, the carrier signal is pulse modulated at selected pulse repetition frequencies with the selected PRF transmitted as first-order sideband components of the fixed carrier frequency. PRF selection is made in accordance with input digital data. A remotely-disposed command link receiver processes the incoming carrier wave and its sideband components to reconstruct the information contained in the transmitted data rates. Sensitivity and optimum detection by the command link receiver is achieved in a special manner that includes a phase locking of the received carrier frequency to the generated carrier frequency.

Abstract: A semi-active radar receiver for receiving a sequence of radar pulses and providing radar timing signals in response thereto. In a most general sense, the semi-active receiver of the present invention includes a receiver 10 for receiving a direct transmission of a series of pulses from a radar transmitter 2 and for providing a series of first signal pulses in response thereto. A range gate generator 42 is included for processing the series of first pulses to provide said radar timing signals. In a more specific embodiment, the receiver includes a filter 40 for processing said received pulses and deriving estimates of the timing of the receipt thereof. The estimates are then used by the range gate generator 42 to provide said radar timing signals.

Abstract: An improved direct, two-way data link is disclosed. The improved data link is used with an electronically steerable active array 10. The uplink comprises a transmitter radar means 60 mounted in a first vehicle for providing a first data signal and transmitting this first data signal as a first radar data signal to a second vehicle and radar receiver means 130 mounted in this second vehicle for extracting the first data signal from the first radar data signal. The downlink comprises transmitter radar means 150 mounted in the second vehicle for providing a second data signal and transmitting this second data signal as a second radar data signal and radar receiver means 80 mounted in the first vehicle for extracting the second data signal from the second radar data signal.

Abstract: A method and a system which allows for simultaneous radar tracking and data communication. The method of the invention includes the steps of (a) encoding a radar transmit signal with message data in a transmitter; (b) receiving transmitted returns of said encoded radar signal in a first receiver; (c) decoding said received return signal to eliminate message data; (d) receiving said encoded radar signal in a second receiver; and (e) decoding said received radar signal to extract said message data. The system of the invention includes a transmitter equipped for encoding a radar transmit signal with message data; a first receiver capable of decoding returns from said transmitter signal to eliminate said message data; and a second receiver capable of decoding said radar signal to extract the message data.