Westinghouse Electric Corporation

United States of America As Represented by the Secretary of the Air Force

Northrop Grumman Systems Corporation

USA As Represented by Secretary of the Navy

Martin J Decker

Francis W Hopwood

Stephen P Caldwell

Henry E Lee

David L Richardson

Scott Alan Stratmoen

Elbert L Cole, Jr

Jerry A Kane

George A Ioannidis

Giora A Bendor

Daniel N Held

Charles Y Chen

Stephen Warejko

Robert A Jelen

A method of operating a multibeam radar carried on a platform flying a mission over a prescribed flight path to obtain images of a plurality of target areas, the beams of said radar being the result of respective transmit pulses and beam returns being received by respective receive windows. A range of pulse repetition frequencies and pulse repetition frequency change rates are used in an iterative process to determine non-collision alignments of any combination of transmit pulses and receive windows. When a non-collision alignment is determined the particular arrangement producing that non-collision alignment is used in a simulated flight of the platform to determine dwell time before a collision occurs. An arrangement that produces sufficient dwell time to accomplish a mission is then used in an actual flight of the platform.

Method of operating a multibeam radar

A method of communicating to a RF tag having a low power mode and a scan mode with a radar and an interrogator. The method comprises the steps of alternating the RF tag between the low power mode and the scan mode and then transmitting a wake-up call to the RF tag with the radar. Next, the wake-up call is received from the radar by the RF tag when the RF tag is in the scan mode. Once the wake-up call has been received, the radar will transmit a downlink message to the RF tag. Upon receipt of the downlink message, the RF tag will send an uplinked message to the radar. After the uplink message has been sent to the radar, the RF tag will return to the low power mode. By alternating the RF tag between the low power mode and the scan mode, the power consumption of the RF tag is greatly reduced thereby increasing the battery life thereof.

Tag communication protocol & system

A method and apparatus for controlling a radar beam emitted by a radar sym. The invention produces improved high resolution ground mapping by aligning the antenna isogain or isonull lines with the ground radial lines. The antenna axis is rolled by an angle determined from the geometric principles of the unit vectors along the ground radial lines. A new azimuth pointing angle is then computed and implemented. A new azimuth beamshape, azimuth beamwidth and azimuth beam spoiling factor are also computed and implemented.

Alignment and beam spreading for ground radial airborne radar

A synthetic aperture radar system performing two dimensional monopulse measurement of the return data.

Method and system for sharpening impulse response in a synthetic

The present invention includes an apparatus that prebiases a transmitted radar signal. The prebiasing of the transmit signal automatically aligns the return signals in one dimension or dimensionally transforms the return signals thereby removing the need for one of the dimensional processing operations of a conventinal two dimensional return signal interpolator. A map function generator produces small frequency (phase) changes in the transmitted signal during each pulse over the entire integration or exposure period. The map function generator produces a parabolic frequency change control signal applied during the integration period. The control signal is divided into segments where each segment controls a single transmit pulse. The control signal modifies a linear frequency modulation control signal. conventionally produced by high resolution radar systems.

Coordinate system transformation apparatus for a high resolution radar

A wide-band amplifier apparatus utilizing a low frequency and a high frequency phase lock loop to achieve low phase delay at the loop bandwidth. The bandwidth products of the low and high frequency loop paths are combined and applied to the voltage controlled oscillator to minimize phase delay and to achieve a more stable loop.

Wide-band phase locked loop amplifier apparatus

The acquisition of phase lock to a reference frequency by a signal acquisition system is accomplished using a voltage controlled oscillator, a wideband frequency discriminator, a prepositioning circuit, and a phase lock loop. The voltage controlled oscillator is prepositioned within a loop bandwidth of the reference frequency by the prepositioning circuit and the wide band frequency discriminator which provide coarse tuning. The voltage controlled oscillator achieves phase lock with the reference frequency when it receives the fine tune signal from the phase lock loop. Using both the discriminator and the phase lock loop allows fast acquisition without the need to calibrate the voltage controlled oscillator. Since the discriminator pull-in range is much larger than the phase-lock loop bandwidth, the number of bits can be much smaller than in an acquisition circuit using a digital prepositioning circuit alone.

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Baltimore, MD, United States of America

Martin J Decker