US3610901A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital modified discrete fourier transform doppler radar processor
Assignee: Emerson Electric Co
•
Filing: 1969-09-09
•
Granted: 1971-10-05
•
Expires: 1989-09-09
Abstract
Abstract A system for processing data from Doppler radar returns including a sample and hold circuit, an A/D converter and scratchpad memory which holds the binary data for insertion, on a return-by-return basis, into a main MOS memory. The data is orthogonally extracted from the main memory on a range-by-range basis, each range group or cell being delivered to a digital filter. The binary data is converted to binary logarithm form for addition to a log coefficient weighting function to perform a multiplication in the filter. The filter is a modified discrete Fourier transform filter which acts as a bandpass and eliminates images and clutter. The filtered data is again stored and then converted to analog form for video displays.
Inventors
- 👤 David D Lynch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:03
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/52; G01S13/522; G01S13/524; G01S13/53; G01S13/532; G01S7/00; G01S7/02; G01S7/28; G01S7/285; G01S7/292; G01S7/2923; G06; G06F; G06F7/00; G06F7/38; G06F7/48; G06F7/544; G06F7/556
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
100 words
Apparatus for processing radar return data comprising the combination oF memory means for storing the data from a plurality of returns in binary form in the order in which it is received; means for extracting the binary data from said memory means in sets according to radar range categories of said data; means for digitally filtering said sets of data according to frequency characteristics of said sets of data, including means for generating a threshold level signal and means for comparing filtered data with said threshold level signal; and means for converting said filtered data to analog form for display.
Claim 2
Dependent Claim
100 words
Apparatus for processing radar return data comprising the combination oF memory means for storing the data from a plurality of returns in binary form in the order in which it is received; means for extracting the binary data from said memory means in sets according to radar range categories of said data; means for digitally filtering said sets of data according to frequency characteristics of said sets of data, including means for generating a threshold level signal and means for comparing filtered data with said threshold level signal; and means for converting said filtered data to analog form for display.
Claim 3
Dependent Claim
110 words
Apparatus for processing pulsed radar return information signals in analog form comprising the combination of means for converting the analog signals to digital form; means for storing the digital signals from a plurality of returns on a return-by-return basis; means for reading, on a range-by-range basis, the stored signals from a plurality of ranges, representing a small fraction of the total number of ranges, during each pulse return period; means for digitally filtering said read signals and for rejecting all signals except those in a predetermined band of frequencies; memory means for storing the filtered information signals; and means for extracting the stored signals and converting them to analog form.
Claim 4
Dependent Claim
110 words
Apparatus for processing pulsed radar return information signals in analog form comprising the combination of means for converting the analog signals to digital form; means for storing the digital signals from a plurality of returns on a return-by-return basis; means for reading, on a range-by-range basis, the stored signals from a plurality of ranges, representing a small fraction of the total number of ranges, during each pulse return period; means for digitally filtering said read signals and for rejecting all signals except those in a predetermined band of frequencies; memory means for storing the filtered information signals; and means for extracting the stored signals and converting them to analog form.
Claim 5
Dependent Claim
107 words
A digital filter comprising the combination of means for accepting linear binary data signals and for converting said data signals to signals in binary logarithmic form; means for generating electrical signals representing a coefficient function; means for adding said coefficient function signals to said binary logarithmic data signals; means for converting the sum of said coefficient function signals and said binary logarithmic signals to signals in linear binary form; means for generating a signal representative of threshold; and means for comparing said sum signal with said threshold signal and for providing, as a filter output signal, only those elements of said sum signal which exceed said threshold.
Claim 6
Dependent Claim
107 words
A digital filter comprising the combination of means for accepting linear binary data signals and for converting said data signals to signals in binary logarithmic form; means for generating electrical signals representing a coefficient function; means for adding said coefficient function signals to said binary logarithmic data signals; means for converting the sum of said coefficient function signals and said binary logarithmic signals to signals in linear binary form; means for generating a signal representative of threshold; and means for comparing said sum signal with said threshold signal and for providing, as a filter output signal, only those elements of said sum signal which exceed said threshold.
Claim 7
Dependent Claim
148 words
A digital filter comprising the combination of means for accepting linear binary data signals and for converting said data signals to signals in binary logarithmic form; means for connecting said binary logarithmic signals to a plurality of filter channels, each channel comprising means for generating electrical signals representing a coefficient function, means for adding said coefficient function signals to said binary logarithmic data signals, means for converting the sum of said coefficient function signals and said binary logarithmic signals to signals in linear binary form, means for generating a signal representative of a threshold level calculated from the binary data signals, and means for comparing said sum, in linear binary form, with said threshold signal and for providing, as the output of said channel, only those components of said sum signal which exceed said threshold; and OR circuit means connected to the outputs of all of said channels.
Claim 8
Dependent Claim
148 words
A digital filter comprising the combination of means for accepting linear binary data signals and for converting said data signals to signals in binary logarithmic form; means for connecting said binary logarithmic signals to a plurality of filter channels, each channel comprising means for generating electrical signals representing a coefficient function, means for adding said coefficient function signals to said binary logarithmic data signals, means for converting the sum of said coefficient function signals and said binary logarithmic signals to signals in linear binary form, means for generating a signal representative of a threshold level calculated from the binary data signals, and means for comparing said sum, in linear binary form, with said threshold signal and for providing, as the output of said channel, only those components of said sum signal which exceed said threshold; and OR circuit means connected to the outputs of all of said channels.
Claim 9
Independent Claim
102 words
A method of processing binary signals containing information from successive Doppler radar returns comprising the steps of storing the signals in a memory unit on a return-by-return basis, categorized by range; sequentially reading the signals from the memory, range-by-range; taking the logarithm to the base 2 of the sequentially read information signals; generating a plurality of logarithmic weighting coefficient signals; separately adding each weighting coefficient to the logarithms of the sequentially read information signals; comparing the sums obtained in the adding step to preselected threshold levels; and providing the portions of the sums in excess of the threshold signals as display information.
Claim 10
Independent Claim
102 words
A method of processing binary signals containing information from successive Doppler radar returns comprising the steps of storing the signals in a memory unit on a return-by-return basis, categorized by range; sequentially reading the signals from the memory, range-by-range; taking the logarithm to the base 2 of the sequentially read information signals; generating a plurality of logarithmic weighting coefficient signals; separately adding each weighting coefficient to the logarithms of the sequentially read information signals; comparing the sums obtained in the adding step to preselected threshold levels; and providing the portions of the sums in excess of the threshold signals as display information.
Claim 11
Independent Claim
121 words
A method of processing analog signals containing information from Doppler radar returns comprising the steps of sampling the analog signals and converting the sampled portiOns to linear binary form; storing the linear binary signals in a memory device on a return-by-return basis, categorized by range; sequentially reading the signals from the memory, range-by-range; taking the logarithm to the base 2 of the sequentially read information signals; generating a plurality of logarithmic weighting coefficient signals; separately adding each weighting coefficient to the logarithms of the sequentially read information signals; comparing the sums obtained in the adding step to preselected threshold levels; and converting all portions of the sums thus obtained in excess of the threshold signals to analog form for subsequent display.
Claim 12
Independent Claim
121 words
A method of processing analog signals containing information from Doppler radar returns comprising the steps of sampling the analog signals and converting the sampled portiOns to linear binary form; storing the linear binary signals in a memory device on a return-by-return basis, categorized by range; sequentially reading the signals from the memory, range-by-range; taking the logarithm to the base 2 of the sequentially read information signals; generating a plurality of logarithmic weighting coefficient signals; separately adding each weighting coefficient to the logarithms of the sequentially read information signals; comparing the sums obtained in the adding step to preselected threshold levels; and converting all portions of the sums thus obtained in excess of the threshold signals to analog form for subsequent display.
Claim 13
Dependent Claim
105 words
Apparatus for processing radar return data comprising the combination of memory means for storing the data in binary form in the order in which it is received; means for extracting the data from said memory means in sets according to radar range categories of said data; means for digitally filtering said data comprising a. means for generating a plurality of time weighting digital coefficient signals; b. means for multiplying said sets of data by said digital time weighting coefficient signals; and c. means for comparing the resulting signals with a predetermined threshold level signal; and means for converting said data to analog form for display.
Claim 14
Dependent Claim
105 words
Apparatus for processing radar return data comprising the combination of memory means for storing the data in binary form in the order in which it is received; means for extracting the data from said memory means in sets according to radar range categories of said data; means for digitally filtering said data comprising a. means for generating a plurality of time weighting digital coefficient signals; b. means for multiplying said sets of data by said digital time weighting coefficient signals; and c. means for comparing the resulting signals with a predetermined threshold level signal; and means for converting said data to analog form for display.
Claim 15
Dependent Claim
34 words
Apparatus according to claim 7 wherein said means for digitally filtering said data comprises means for separately summing orthogonal vector components of the product of sets of data and digital time weighting coefficient signals.
Claim 16
Dependent Claim
41 words
Apparatus according to claim 7 wherein said means for digitally filtering said data comprises a plurality of digital filters connected to an output by an OR gating means, each of said filters being adapted to pass data at a different frequency.
Claim 17
Dependent Claim
46 words
Apparatus according to claim 7 including means for generating said threshold level signal comprising means for generating a fixed signal; means for generating a second signal having a level dependent on said unfiltered data, and means for combining said fixed level signal and said second signal.
Claim 18
Dependent Claim
131 words
Apparatus for processing radar return data comprising the combination of memory means for storing the data in binary form in the order in which it is received; means for extracting the data from said memory means in sets according to radar range categories of said data; means for digitally filtering said data, comprising a. means for converting the data extracted from said memory means to binary logarithmic form; b. means for generating a plurality of logarithmic weighting coefficient signals; c. means for adding said logarithmic weighting coefficient signals to said binary logarithmic data; d. means for converting the adder output signals to linear binary form; and e. means for comparing the converted adder output signals to a predetermined threshold level signal; and means for converting said data analog form for display.
Claim 19
Dependent Claim
131 words
Apparatus for processing radar return data comprising the combination of memory means for storing the data in binary form in the order in which it is received; means for extracting the data from said memory means in sets according to radar range categories of said data; means for digitally filtering said data, comprising a. means for converting the data extracted from said memory means to binary logarithmic form; b. means for generating a plurality of logarithmic weighting coefficient signals; c. means for adding said logarithmic weighting coefficient signals to said binary logarithmic data; d. means for converting the adder output signals to linear binary form; and e. means for comparing the converted adder output signals to a predetermined threshold level signal; and means for converting said data analog form for display.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-04 | 1975-04-05 | 1975-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-04 | 1979-04-05 | 1979-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-04 | 1983-04-05 | 1983-10-05 | $7700.00 | Window Closed / Lapsed |