US3790939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Real time synthetic radar
Assignee: CONSTANT ARGEREY 1603 DANBURY DRIVE CLAREMONT CA 91711
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Filing: 1972-05-12
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Granted: 1974-02-05
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Expires: 1992-05-12
Abstract
Abstract A coherent synthetic aperture radar with a scanning transmitter beam and a data processor, preferably operating in real time and preferably with CW transmitter operation, providing target coordinates, including range, without requiring comparison of echo and transmitted pulses for range data.
Inventors
- 👤 J Constant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:21
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/88; G01S13/89; G01S13/90; G01S13/904
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
176 words
A coherent synthetic aperture radar including transmitter, receiver, local oscillator and data processor, said transmitter including an antenna providing a transmitter beam along a boresight axis and means for scanning said beam about a scan axis, said reciver including an antenna for receiving signals from storage illuminated by the scanning transmitter beam, with said oscillator providing a common reference frequency for said transmitter and receiver, with said data processor having as an input from the receiver output, a pulse modulated, frequency modulated signal in the form of a chirp pulse train echo from a target illuminated by repeated scanning, with the chirp due to target doppler and the pulse train due to scanning over the target, and with said data processor providing an output signal in the form of a short pulse following a number of illuminations of a target by scanning, with the time of occurrence and separation of pulses in the pulse train of the input signal providing the coordinates and resolution of coordinates for each occurrence of the data processor output signal pulse.
Claim 2
Dependent Claim
176 words
A coherent synthetic aperture radar including transmitter, receiver, local oscillator and data processor, said transmitter including an antenna providing a transmitter beam along a boresight axis and means for scanning said beam about a scan axis, said reciver including an antenna for receiving signals from storage illuminated by the scanning transmitter beam, with said oscillator providing a common reference frequency for said transmitter and receiver, with said data processor having as an input from the receiver output, a pulse modulated, frequency modulated signal in the form of a chirp pulse train echo from a target illuminated by repeated scanning, with the chirp due to target doppler and the pulse train due to scanning over the target, and with said data processor providing an output signal in the form of a short pulse following a number of illuminations of a target by scanning, with the time of occurrence and separation of pulses in the pulse train of the input signal providing the coordinates and resolution of coordinates for each occurrence of the data processor output signal pulse.
Claim 3
Dependent Claim
13 words
Apparatus as defined in claim 1 wherein said transmitter is a CW transmitter.
Claim 4
Dependent Claim
13 words
Apparatus as defined in claim 1 wherein said transmitter is a pulsed transmitter.
Claim 5
Dependent Claim
15 words
Apparatus as defined in claim 1 wherein said transmitter and receiver have a common antenna.
Claim 6
Dependent Claim
14 words
Apparatus as defined in claim 1 wherein said transmitter and receiver have separate antennae.
Claim 7
Dependent Claim
16 words
Apparatus as defined in claim 1 wherein said data processor is a real time data processor.
Claim 8
Dependent Claim
15 words
Apparatus as defined in claim 1 wherein said data processor includes a pulse compression filter.
Claim 9
Dependent Claim
14 words
Apparatus as defined in claim 1 wherein said data processor includes a matched filter.
Claim 10
Dependent Claim
14 words
Apparatus as defined in claim 1 wherein said data processor includes an autocorrelation unit.
Claim 11
Dependent Claim
15 words
Apparatus as defined in claim 1 wherein siad data processor includes a cross correlation unit.
Claim 12
Dependent Claim
16 words
Apparatus as defined in claim 1 wherein said data processor includes a fm recirculating delay line.
Claim 13
Dependent Claim
118 words
Apparatus as defined in claim 1 wherein said data processor includes: a delay line having an input and an output, with the delay line output providing the data processor output signal pulse; a mixer having first and second inputs and an output, with the mixer output connected to the delay line input and with the data processor input connected to the first mixer input; and a feedback circuit connected between the delay line output and the second mixer input, and including an amplifier having a gain of less than unity and a frequency shifter for shifting the frequency of the feedback signal at the second mixer input to that of the input signal at the first mixer input.
Claim 14
Dependent Claim
27 words
Apparatus as defined in claim 1 wherein said transmitter is a CW transmitter and said data processor includes a fm recirculating delay line operating in real time.
Claim 15
Dependent Claim
21 words
Apparatus as defined in claim 1 wherein said antenna has a beamwidth Beta 2 pi and a scan rate omega 0.
References Cited (Backward Citations)
US3662384A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |