AUTOMATIC DATA PROCESSOR

• US 3,836,964 A
• Filed: 10/18/1967
• Issued: 09/17/1974
• Est. Priority Date: 10/18/1967
• Status: Expired due to Term

• Current Assignee: Norol T. Evans
• Original Assignee: Norol T. Evans
• Inventors: Evans, Norol T.
• Primary Examiner(s): Tubbesing, T. H.
• Application Number:
  US04/676,243
• Time in Patent Office: 2,526 Days
• Field of Search: 343/5DP,7A
• US Class Current: 342/90
• CPC Class Codes: G01S 13/72 for two-dimensional tracking, e.g. combination of angle and range tracking, track-while-scan radar
• CPC Class Codes: G01S 7/2923 based on data belonging to a number of consecutive radar periods

Abstract

An automatic data processor which allows a completely automatic track-while-scan function to be performed with a pencil beam radar. Multi-level detection systems are employed to process quantized and verified signals which have been reduced from an analog signal to digital data words indicative of the weight thereof. The codes in the verifier are compared with other codes so that only predetermined known values shown on one of two input channels are gated for further processing. A video correlator is employed which implements a moving window detector in three dimensions to help organize the information for subsequent processing. When the data words in the same range bin on adjacent beams in azimuth and elevation meet a predetermined criteria, a target detection is declared. The detection information is then sent through a detection blanking system to a beamsplitter and buffer unit. The video correlator also keeps track of how many detections occur sequentially in both azimuth and elevation at the same range bin. If the number of detections exceed a preset value, the clutter reject bit will be set and the beamsplitter will reject this data as clutter. The beamsplitter makes use of the video data words on adjacent beams in both azimuth and elevation to calculate beamsplit coordinates, and thereby determines the target location within a fraction of a beamwidth. A detector criteria control unit performs two functions for reducing the sensitivity of the system in automatically selected portions of the three-dimensional surveillance volume. The criteria control unit maps all target reports and distinguishes them from clutter. It blanks signals to a utilization device when there is clutter present; it may also modify the quantizer to reduce its sensitivity without blanking in certain cells. The criteria control unit also may incorporate a target rate counter for reducing detection sensitivity in sectors with a high detection rate.

Claims

1. A data processor for processing radar data from a pair of receivers having differing bandwidths, said processor comprising:

a first quantizer having an input channel coupled to one of said receivers and an output channel, the output channel providing quantized data words indicative of data provided to the input channel;

a second quantizer having an input channel coupled to said other receiver and having an output channel, the output channel providing quantized data words indicative of the data provided to the input channel thereof;

a data verifier for verifying that the data words from said first and second quantizers are within a preselected relationship to each other;

said data verifier having a pair of input channels coupled to the output channels of said quantizers, a signal output channel and a control output channel;

a correlator having an input channel coupled to the signal output channel of said data verifier and having an output channel, said correlator including means for recognizing predetermined patterns of data words provided by the output channel of said verifier and for providing an output indicative of the predetermined data word recognized; and

means coupled to said control output channel of said verifier and to the output channel of said correlator for inhibiting the output of said correlator if the data words from said first and second quantizers are not within said predetermined relationship.

2. The radar data processor of claim 1 further comprising an off-line detector having a first data channel coupled to said correlator and a second data channel coupled to the output signal channel of said data verifier, and including means for modifying the data words from the output channel of said data verifier as a function of the number and magnitude of signals received from each associated incremental volume of space.

3. In an automatic multi-level radar detection system having a source of return signAls from a plurality of range bins in a surveillance volume in azimuth and elevation dimensions, said source including a pair of receivers having differing bandwidths;

a radar data processor comprising;

a first quantizer having an input channel coupled to one of said receivers and an output channel, the output channel providing digitized data words indicative of the input to said first quantizer;

a second quantizer having an input channel coupled to said other receiver and having an output channel, the output channel providing digitized data words indicative of the input to said second quantizer;

a data verifier for verifying that the data words from said first and second quantizers are within a preselected relationship to each other, said data verifier having a pair of input channels coupled to the output channel of said quantizers, a signal output channel and a control output channel;

a correlator having an input channel coupled to the output channel of said data verifier and having an output channel, said correlator including means for recognizing predetermined patterns of data words provided by the output channel of said verifier and for providing an output indicative of the predetermined data word recognized; and

means coupled to said control output channel of said verifier and to the output channel of said correlator for inhibiting the output of said correlator if the data words from said first and second quantizers are not within said predetermined relationship.

4. The radar data processor of claim 3 further comprising an off-line detector having a first data channel coupled to said correlator and a second data channel coupled to the output signal channel of said data verifier and including means for modifying the data words from the output channel of said data verifier as a function of the number and magnitude of signals received from an associated incremental surveillance volume.

5. In the automatic multi-level detection system as defined in claim 4 wherein said off-line detector comprising:

a means for storing a target-detection-history indicating code for each multi-range bin incremental volume of the surveillance radar;

a means for using each code to control the quantized video returns from the range bins of the incremental volume associated with the code; and

a means for updating during each of a sequence of update cycles the code of each incremental volume as a function of the code characteristics and a target report from said correlating means provided during the update cycle for any of the range bins in the incremental volume.

6. In the automatic multi-level detection system as defined in claim 5 wherein the code at the beginning of an update cycle is indicative of the history of detection of the targets in any of the range bins of an incremental volume associated with the code during preceding update cycles in said sequence, and wherein the quantized video returns from each range bin are represented by a multi-bit number whose numerical value is indicative of the peak of the video returns with respect to a preselected threshold level, said utilizing means subtracting a first numerical quantity from the quantized video returns of all range bins in an incremental volume when the code represents target detection in two successive update cycles and a second numerical quantity larger than said first, when the code represents target detection in three successive update cycles.

7. In the automatic multi-level detection system as defined in claim 6 and further comprising:

a means for blanking the supply of target reports from said receiving system from range bins in a given incremental volume when the code associated with said volume is indicative of target detection in a preselected number of successive update cycles.

8. In the automatic multi-level detection system as defined in claim 5 and further comprising:

a means for modifying the quantized video returns as a function of the rate of target reports from said correlator.

9. In the automatic multi-level detection system as defined in claim 5 further comprising:

a means for modifying the quantized video returns supplied to said correlator as a function of the rate at which quantized video returns above a selected value are developed.