Amti range ambiguity resolver

Claim 2

In a pulsed energy system employing at least a pair of pulse repetition frequencies, means for resolving an ambiguous range indicative of a detected moving target and comprising doppler processing means responsive to target echo signals received by a receiver of said system for providing at least a pair of clutter-free range trace signals, each said range trace signal indicative of the system response to a mutually exclusive one of said pulse repetition frequencies; and correlation means for time-domain correlation of said pair of range trace signals as a function of discrete time n Delta T, and comprising a plurality of coincidence detection means for comparing one of said range trace signals and a delayed second one of said range trace signals, a successive one of said plurality of coincident detection means employing a successively increased delay (n Delta T) of said delayed second range trace signal, where n is an integer number including zero and where Delta T corresponds to the range time difference between the respective pulse repetition intervals associated with said pair of pulse repetition frequencies.

Claim 3

The device of claim 1 in which said doppler processing means includes a pair of time-duplexed doppler storage means, each arranged to be responsive to the pulse repetition interval of a selected one of said system pulse repetition frequencies for providing a doppler map; and doppler filter means having an input arranged to be responsive to an alternate one of said doppler storage means for providing a clutter-free range trace output signal.

Claim 4

The device of claim 1 in which said correlation means includes multiple channel secondary storage means responsively coupled to an output of said doppler processing means, each channel of said storage means being responsive to the clutter-free range trace signal associated with a mutually exclusive one of said pulse repetition frequencies, for providing concomitant read-out of said two range trace signals, one of said range-trace signals being read-out at successive delays n Delta T relative to the other of said range trace signals, where n is an integer number including zero and Delta T corresponds to the range time difference between the pulse repetition intervals associated with said pair of pulse repetition frequencies; and coincidence gate logic means responsive to said read-out of one of said channels and respective ones of said delayed readouts of the other of said channels for indicating that integer number (n) of ambiguous pulse repetition intervals associated with the apparent range time for a detected moving target.

Claim 5

The device of claim 1 in which said correlation means includes multiple channel secondary storage means responsively coupled to an output of said doppler processing means, each channel of said storage means being responsive to the clutter-free range trace signal associated with a mutually exclusive one of said pulse repetition frequencies, for providing concomitant read-out of said two range trace signals, range-time registration of one of said range-trace signals being successively delayed n Delta T relative to the other of said range trace signals, where n is an integer number including zero and Delta T corresponds to the range time difference between the pulse repetition intervals associated with said pair of pulse repetition frequencies; and ambiguity resolver logic means comprising a plurality (n + 1) of coincidence gates each responsive to said read-out of one of said channels and to a mutually exclusive of said delayed read-outs of the other of said channel for indicating that integer number (n) of ambiguous pulse repetition intervlas associated with the apparent range time for a detected moving target.

Claim 6

In a pulsed energy system employing at least a pair of pulse repetition frEquencies and adapted for substantially clutter-referenced detection of moving targets, means for resolving the ambiguous range indication of a detected moving target occurring at a range greater than that corresponding to the least pulse repetition interval provided by said pulse repetition frequencies, and means responsive to a clutter referenced video receiver output of said system for providing that doppler map associated with each of said pulse repetition frequencies, a preselected range time increment difference ( Delta T) existing between the pulse repetition intervals of at least two of said pulse repetition frequencies; a thresholded doppler bandpass filter responsive to a doppler read-out of successive ones of said doppler maps for providing a substantially clutter-free range trace output; multiple-channel recording means responsively coupled to an output of said filter for separately recording the successive clutter-free range-trace outputs, a first channel of said recording means having a reference read head, and a successive channel of said recording means having a preselected number of regularly spaced read heads, the spacing between adjacent readheads corresponding to a range time increment of said recorded range trace outputs, the phase-spacing of a reference read head on said successive one (n) of said channels differing from that of said first channel by an amount corresponding to the preselected range time incremental difference (n Delta T) therebetween; and a like plurality of logic means as said preselected number of read heads per successive channel, each logic means responsive to said read-head of said first channel and to a mutually exclusive one of the read heads of a successive channel of said recording means for providing a two-state logic output indicative of the coincidence of any two of the inputs thereto from said multiple channel recording means for indicating that integer number (n) of ambiguous pulse repetition intervals associated with the apparent range time TA of a detected moving target.

Claim 7

In a pulsed energy system employing at least a pair of pulse repetition frEquencies and adapted for substantially clutter-referenced detection of moving targets, means for resolving the ambiguous range indication of a detected moving target occurring at a range greater than that corresponding to the least pulse repetition interval provided by said pulse repetition frequencies, and means responsive to a clutter referenced video receiver output of said system for providing that doppler map associated with each of said pulse repetition frequencies, a preselected range time increment difference ( Delta T) existing between the pulse repetition intervals of at least two of said pulse repetition frequencies; a thresholded doppler bandpass filter responsive to a doppler read-out of successive ones of said doppler maps for providing a substantially clutter-free range trace output; multiple-channel recording means responsively coupled to an output of said filter for separately recording the successive clutter-free range-trace outputs, a first channel of said recording means having a reference read head, and a successive channel of said recording means having a preselected number of regularly spaced read heads, the spacing between adjacent readheads corresponding to a range time increment of said recorded range trace outputs, the phase-spacing of a reference read head on said successive one (n) of said channels differing from that of said first channel by an amount corresponding to the preselected range time incremental difference (n Delta T) therebetween; and a like plurality of logic means as said preselected number of read heads per successive channel, each logic means responsive to said read-head of said first channel and to a mutually exclusive one of the read heads of a successive channel of said recording means for providing a two-state logic output indicative of the coincidence of any two of the inputs thereto from said multiple channel recording means for indicating that integer number (n) of ambiguous pulse repetition intervals associated with the apparent range time TA of a detected moving target.

Claim 8

In a pulsed energy system employing at least a pair of pulse repetition frequencies, the combination comprising means for operating a transmitter of said system at a successive one of a preselected plurality of pulse repetition frequencies for a preselected number of successive pulse repetition intervals; doppler processing means responsive to target echo signals received by a receiver of said system for providing at least a pair of clutter-free range trace signals, each said range trace signal indicative of the system response to a mutually exclusive one of said pulse repetition frequencies; and correlation means for time-domain correlation of said pair of range trace signals as a function of discrete time n Delta T, and comprising a plurality of coincidence detection means for comparing one of said range trace signals and a delayed second one of said range trace signals, a successive one of said plurality of coincident detection means employing a successively increased delay (n Delta T) of said delayed second range trace signal, where n is an integer number including zero and where Delta T corresponds to the time difference between the pulse repetition intervals associated with said pair of pulse repetition frequencies, whereby the true range time of the target may be determined as the sum of the apparent range time and that delay (n Delta T) associated with the registry coincidence of a portion of said one of said range trace signals with a portion of said delayed other one of said range trace signals.

Claim 9

In a pulsed energy system employing at least a pair of pulse repetition frequencies, the combination comprising means for operating a transmitter of said system at a successive one of a preselected plurality of pulse repetition frequencies for a preselected number of successive pulse repetition intervals; doppler processing means responsive to target echo signals received by a receiver of said system for providing at least a pair of clutter-free range trace signals, each said range trace signal indicative of the system response to a mutually exclusive one of said pulse repetition frequencies; and correlation means for time-domain correlation of said pair of range trace signals as a function of discrete time n Delta T, and comprising a plurality of coincidence detection means for comparing one of said range trace signals and a delayed second one of said range trace signals, a successive one of said plurality of coincident detection means employing a successively increased delay (n Delta T) of said delayed second range trace signal, where n is an integer number including zero and where Delta T corresponds to the time difference between the pulse repetition intervals associated with said pair of pulse repetition frequencies, whereby the true range time of the target may be determined as the sum of the apparent range time and that delay (n Delta T) associated with the registry coincidence of a portion of said one of said range trace signals with a portion of said delayed other one of said range trace signals.