Variable PRF target tracking radar
AssigneeWestinghouse Electric Corp.
InventorRobert R. Campbell
Life of this patent
Estimating the term…
Abstract
A high PRF pulse doppler radar for tracking moving targets is described wherein the PRF of the transmitted signal is varied within predetermined PRF limits to keep the target reflected high PRF signal centered within the receive gate of the radar and wherein spurious signals incidentally generated by the action of the receive gate are reduced below the receiver noise level. In the event of temporary target reflected signal loss, the PRF of the transmitted signal is varied within predetermined PRF limits based upon the velocity and range estimate of the target to keep subsequent target reflected signals centered within the receive gate of the radar.
Claims14
A method of tracking a moving target in a high PRF radar mode wherein initial target range and doppler frequency information is provided, comprising
- generating a high PRF signal, said signal being constituted by a series of time spaced pulses,
- transmitting said high PRF signal,
- repeatedly receiving at least a portion of one of said pulses of target reflected high PRF signal during a predetermined receive time interval between said time-spaced pulses of said high PRF signal being transmitted,
- reducing spurious signals in the target reflected high PRF signal below a predetermined level which are incidentally generated by modulation of the main beam clutter, said modulation results from receiving during said predetermined receive time intervals,
- tracking the doppler frequency of said target reflected signals to provide a signal indicative of target velocity,
- generating a target range signal indicative of the present target range utilizing said initial range, target velocity signal and the time lapsed from the time of the initial range measurement,
- repeatedly comparing the arrival of one of said pulses of a target reflected high PRF signal with said predetermined receive time interval to provide an early/late signal indicative of whether said pulse of a target reflected high PRF signal is centered with respect to said predetermined receive time interval,
- varying the PRF of said high PRF signal by calculating a new PRF based upon said target range, target velocity and early/late signal to align said pulses of said target reflected signal towards the center of said predetermined receive time intervals.
A pulse doppler radar for tracking a moving target wherein initial target range and doppler frequency information is provided, comprising:
- means for generating a high PRF signal, said signal being constituted by a series of time spaced pulses,
- means for transmitting said high PRF signal,
- means for repeatedly receiving at least a portion of one of said pulses of a target reflected high PRF signal during a predetermined receive time interval between said time-spaced pulses of said high PRF signal being transmitted,
- means for reducing spurious signals in the target reflected high PRF signal below a predetermined level which are incidentally generated by modulation of the main beam clutter, said modulation results from receiving during said predetermined receive time intervals,
- means for tracking the doppler frequency of said target reflected signals to provide a signal indicative of target velocity,
- means for generating a target range signal indicative of the present target range utilizing said initial range, target velocity signal and the time lapsed from the time of the initial range measurement,
- means for repeatedly comparing the arrival of one of said pulses of a target reflected high PRF signal with said predetermined receive time interval to provide an early/late signal indicative of whether said pulse of a target reflected high PRF signal is centered with respect to said predetermined receive time interval,
- means for varying the PRF of said high PRF signal by calculating a new PRF based upon said target range, target velocity and early/late signal to align said pulses of said target reflected signal towards the center of said predetermined receive time intervals.
Dependencies are inferred from the claim text.