Raytheon Company

Hughes Aircraft Company

John K Keigharn

Irwin L Newberg

Bill H Otoide

Garin S Bircsak

Robert R Hayes

Adrian E Popa

Harry T Wang

Jonathan D Gordon

Robert W Erwin

Jorge L Barboza

Warren J Montague

A system for generating a simulated radar return signal. The novel system includes a processor adapted to receive target and waveform parameters and in accordance therewith generate a composite digital signal, and a digital to analog converter adapted to convert the digital signal to an analog signal. The system also includes an upconverter adapted to convert the analog signal to radio frequency. The processor calculates time-domain digital data samples representing a composite radar return waveform based on the target and waveform parameters. These data samples are output at each time interval that the digital to analog converter samples data. The composite waveform can include returns from a large number of targets and from targets embedded in clutter. The system can also be adapted to test a radar system having multiple antenna ports by replicating the basic design for each port.

Arbitrary radar target synthesizer (arts)

An automated simulator for radar and sonar applications. The inventive simulator is implemented in hardware and generates current parameters with respect to a simulated target in response to a plurality of initial values with respect thereto. In the illustrative embodiment, the initial values include range, velocity, and acceleration and are stored in first, second and third register respectively. In the best mode, the invention is implemented in a field-programmable gate array. The inventive target simulator also includes a range delay circuit for generating a simulated return from the simulated target. The range delay circuit includes logic for determining whether a simulated pulse train to be received is ambiguous or unambiguous and adjusting the pulse repetition rate of the pulse train accordingly. The range delay circuit calculates die initial time that a packet needs to make the trip to and from the target. Then, in the ambiguous case, the circuit only calculates how long it takes between pulses to arrive rather than the entire round trip. When the round trip distance and the ambiguous time are identical, the range delay circuit calculates both ambiguous and unambiguous signals and signals the return of whichever type arrives first. After the initial rate is calculated then the shortest calculation between the ambiguous and unambiguous pulses determine the timing for the next returned pulse.

Automated target generator range and doppler calculator

A radar target simulator for generating simulated targets used in testing a radar system. Simulated targets are generated out of the radar system noise. The radar system includes a radar receiver coupled to a receive antenna. The simulator has an input for sampling a transmitted output signal from the radar system. A first reference oscillator is provided for generating a first reference signal, and a first mixer is coupled to the first reference oscillator for mixing the first reference signal with the sampled signal from the radar system to provide a simulated target signal. A laser is coupled to the first mixer for generating a light output signal that corresponds to the simulated target signal. A plurality of selectable delay paths that each have a different predetermined delay length are coupled to the laser. A photodetector is coupled to the plurality of delay paths for convening the light output signal derived from a selected one of the delay paths into a radio frequency (RF) simulated target signal. The photodetector is coupled to an output circuit for transmitting the RF simulated target signal to the radar system. A variable attenuator may be coupled between the photodetector and the output circuit for variably controlling the power of the RF simulated target signal. The simulator may further include Doppler signal generator that comprises a second reference oscillator for generating second and third reference signals. A third mixer is coupled to the first and second reference oscillators for mixing the first and second reference signals to produce a difference signal. A direct digital synthesizer is coupled to the second reference oscillator for receiving a command signal and the third reference signal, and for generating a Doppler output signal in response thereto. A fourth mixer is coupled to the second reference oscillator for receiving the third reference signal and to the direct digital synthesizer for receiving the Doppler signal, and for generating an intermediate Doppler signal in response thereto. A fifth mixer is coupled to the third and fourth mixers and to the output means for mixing the difference signal and the intermediate Doppler signal to produce a simulated target Doppler signal in response thereto that is the RF simulated target signal.

Portable radar target simulator

A programmable fiber optic delay system employs multiple programmable fiber optic delay lines, and switches among the delay lines for inclusion in an overall delay path. Switching among the delay lines is coordinated with the programming of those lines so that only a delay line with a settled delay program is included in the overall delay path. Each delay line consists of a plurality of fiber optic segments of varying length. The line's delay is programmed by switching in particular segments whose aggregate lengths correspond to a desired delay period. The multiple delay lines are used to simulate target speed and distance for use in testing a radar system. The programming of each individual delay line and the switching between lines is preferably controlled by a computer resident in the target simulator.

Programmable fiber optic delay line, and radar target simulation system

Growing community of inventors

Rancho Palos Verdes, CA, United States of America

John K Keigharn