System for discriminating between high and low speed targets

Claim 2

In a system adapted for alternately transmitting groups of energy pulses having first and second pulse repetition frequencies, during first and second pulse repetition frequency modes, respectively; and for receiving returned energy reflected from objects and providing received signals indicative of said returned energy, a moving target processor comprising: filter means, responsive to said received signals, and programmed to have a first preselected response characteristic during said first modes, and a second preselected response characteristic during said second modes, such that its response is substantially the same during both modes for received signals from objects moving at a speed less than a preselected value, and its response to received signals from objects moving at speeds greater than said preselected value varies between said modes; and means for monitoring the output signals from said filter means and for sensing variations in the output signals for the same objects between said modes; whereby the presence of said variations is indicative of an object moving at a speed greater than said preselected value.

Claim 3

The processor of claim 1 wherein said means for monitoring includes means for integrating said output signals, for each of said objects, produced during said first modes and for providing first integrated output signals indicative thereof; means for integrating the output signals, for each of said objects, produced during said second modes and for producing second integrated output signals indicative thereof; and means for sensing variations in said first and second integrated output signals for each of said objects.

Claim 4

The processor of claim 2 wherein said means for monitoring further includes means for providing a target signal if said sensed variations exceed a threshold level.

Claim 5

ThE processor of claim 3 wherein said means for monitoring further comprises means for adapting said threshold level as a function of said integrated output signals.

Claim 6

A moving target detector system comprising: means for transmitting groups of energy pulses such that different groups have different pulse repetition rates; means for receiving energy reflected from said objects and for producing received signals indicative thereof; filter means for producing output signals, in response to received signals from objects moving slower than a preselected speed, which are substantially invariant to pulse repetition rate changes; and for producing output signals, in response to received signals from objects moving faster than said preselected speed, which vary with changes in the pulse repetition rate; and means for monitoring said output signals and for sensing variations in output signals for the same object, derived from energy pulse groups have different pulse repetition rates; whereby the presence of said variations is indicative of an object moving at a speed greater than said preselected speed.

Claim 7

A moving target detector system comprising: means for transmitting groups of energy pulses such that different groups have different pulse repetition rates; means for receiving energy reflected from said objects and for producing received signals indicative thereof; filter means for producing output signals, in response to received signals from objects moving slower than a preselected speed, which are substantially invariant to pulse repetition rate changes; and for producing output signals, in response to received signals from objects moving faster than said preselected speed, which vary with changes in the pulse repetition rate; and means for monitoring said output signals and for sensing variations in output signals for the same object, derived from energy pulse groups have different pulse repetition rates; whereby the presence of said variations is indicative of an object moving at a speed greater than said preselected speed.

Claim 8

The system of claim 5 wherein said means for monitoring includes means for integrating the output signals for the same object, derived from successive energy groups with the same pulse repetition rate; and means for sensing variations in the integrated output signals, for the same object, formed during the different pulse repetition rate periods.

Claim 9

The system of claim 6 wherein said means for monitoring further includes means for providing a target signal if the variations in said integrated output signals exceeds a threshold level.

Claim 10

The system of claim 7 wherein said means for monitoring further comprises means for adapting said threshold level as a function of the integrated output signals.

Claim 11

The system of claim 5 wherein said filter means includes a programmable filter; and programming means, synchronized with said transmitting means, for programming said filter to have different preselected response characteristics during intervals received signals having different pulse repetition rates are processed.

Claim 12

The system of claim 9 wherein said programmable filter is a digital filter; and said means for programming includes means for applying different preselected sets of weighting coefficients to said digital filter during intervals received signals having different pulse repetition rates are processed.

Claim 13

A moving target detector system comprising: means for alternately transmitting groups of energy pulses at first and second pulse repetition rates during first and second pulse repetition frequency modes, respectively; means for receiving energy refelcted from objects and for producing received signals indicative thereof; a programmable filter; means for applying said received signals to said programmable filter; programming means, synchronized by said transmitting means, for programming said filter to have a first preselected response characteristic during said first modes, and a second preselected response characteristic during said second modes; such that received signals for objects moving slower than a preselected speed are processed with substantially the same transfer function during both modes, and received signals for objects moving faster than a preselected speed are processed with different transfer functions during said two modes; and means for monitoring the output signals from said filter and for sensing variations in said output signals, for the same object, between said first and second modes.

Claim 14

A moving target detector system comprising: means for alternately transmitting groups of energy pulses at first and second pulse repetition rates during first and second pulse repetition frequency modes, respectively; means for receiving energy refelcted from objects and for producing received signals indicative thereof; a programmable filter; means for applying said received signals to said programmable filter; programming means, synchronized by said transmitting means, for programming said filter to have a first preselected response characteristic during said first modes, and a second preselected response characteristic during said second modes; such that received signals for objects moving slower than a preselected speed are processed with substantially the same transfer function during both modes, and received signals for objects moving faster than a preselected speed are processed with different transfer functions during said two modes; and means for monitoring the output signals from said filter and for sensing variations in said output signals, for the same object, between said first and second modes.

Claim 15

The system of claim 11 wherein said programmable filter comprises a digital filter; and said programming means includes means for applying first and second preselected sets of weighting coefficients to said digital filter during said first and second modes, respectively.

Claim 16

The system of claim 11 wherein said means for monitoring includes means for integrating the output signals for The same object during said first modes and for producing first integrated output signals indicative thereof, means for integrating the output signals for the same objects during said second modes and for producing second integrated output signals indicative thereof, and means for sensing variations in said first and second integrated output signals for each of said objects.

Claim 17

The system of claim 13 wherein said means for monitoring includes means for providing a target signal if said sensed variations exceed a threshold level.

Claim 18

The system of claim 14 wherein said means for monitoring further comprises means for adapting said threshold level as a function of said integrated output signals.

Claim 19

A moving target detector system comprising: means for alternately transmitting groups of energy pulses at first and second pulse repetition rates during first and second pulse repetition frequency modes, respectively; means for receiving energy reflected from objects and for producing received signals indicative thereof; filter means for processing said received signals and producing output signals as a function of said received signals and of a preselected filter response characteristic; and means for monitoring the output from said filter means and for sensing variations in said output signals, for the same object, between said first and second modes, said means for monitoring includes means for integrating the output signals for the same object during said first modes and for producing first integrated output signals indicative thereof, means for integrating the output signals for the same objects during said second modes and for producing second integrated output signals indicative thereof, and means for sensing variations in said first and second integrated output signals for each of said objects; whereby the presence of the said variations is indicative of an object moving faster than a preselected speed.

Claim 20

A moving target detector system comprising: means for alternately transmitting groups of energy pulses at first and second pulse repetition rates during first and second pulse repetition frequency modes, respectively; means for receiving energy reflected from objects and for producing received signals indicative thereof; filter means for processing said received signals and producing output signals as a function of said received signals and of a preselected filter response characteristic; and means for monitoring the output from said filter means and for sensing variations in said output signals, for the same object, between said first and second modes, said means for monitoring includes means for integrating the output signals for the same object during said first modes and for producing first integrated output signals indicative thereof, means for integrating the output signals for the same objects during said second modes and for producing second integrated output signals indicative thereof, and means for sensing variations in said first and second integrated output signals for each of said objects; whereby the presence of the said variations is indicative of an object moving faster than a preselected speed.