US3866222A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Perspective radar display using linear vertical sweep
Assignee: BAE Systems Aircraft Controls Inc
•
Filing: 1973-08-27
•
Granted: 1975-02-11
•
Expires: 1993-08-27
Abstract
Abstract A perspective radar display is provided on a cathode ray tube having a linear vertical sweep by feeding the video echo return signals to the video input of the cathode ray tube in a nonlinear manner as opposed to vertically sweeping in a non-linear manner. Essentially, the video signals are stored linearly with time during a first time interval corresponding to the time interval between successive transmitter triggering pulses defining the radar pulse repetition frequency, and then released to the video input of the cathode ray tube hyperbolically with time over a second time interval measured from the beginning to the end of a vertical sweep so that the signals are passed to the cathode ray tube at a faster rate during the later portion of the sweep as compared to the earlier portion to thereby provide a perspective display.
Inventors
- 👤 David W Young
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 05:04
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/04; G01S7/06; G01S7/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
178 words
A method of providing a perspective radar display of terrain in front of an aircraft equipped with a high resolution rapid scanning radar having a cathode ray tube with a vertical sweep for displaying video return echo signals along the sweep path, comprising the steps of: a. storing the video signals linearly with time, received during a first interval corresponding to the time interval between successive transmitter triggering pulses defining the radar pulse repetition frequency; b. releasing the stored video signals in accord with a given function over a second time interval measured from the beginning to the end of a vertical Sweep; and c. varying the form of the function defining the rate of release of the video signals with changes in altitude of the aircraft whereby the video signals are passed to the cathode ray tube and displayed at a faster rate during the later portion of the sweep as compared to the earlier portion to thereby provide a perspective display and whereby a desired perspective display is maintained as the altitude of the aircraft varies.
Claim 2
Independent Claim
178 words
A method of providing a perspective radar display of terrain in front of an aircraft equipped with a high resolution rapid scanning radar having a cathode ray tube with a vertical sweep for displaying video return echo signals along the sweep path, comprising the steps of: a. storing the video signals linearly with time, received during a first interval corresponding to the time interval between successive transmitter triggering pulses defining the radar pulse repetition frequency; b. releasing the stored video signals in accord with a given function over a second time interval measured from the beginning to the end of a vertical Sweep; and c. varying the form of the function defining the rate of release of the video signals with changes in altitude of the aircraft whereby the video signals are passed to the cathode ray tube and displayed at a faster rate during the later portion of the sweep as compared to the earlier portion to thereby provide a perspective display and whereby a desired perspective display is maintained as the altitude of the aircraft varies.
Claim 3
Dependent Claim
25 words
The method of claim 1, in which the vertical sweep for displaying the video signals is linear and said given function is a hyperbolic function.
Claim 4
Dependent Claim
41 words
The method of claim 1 in which said second given time interval is longer than said first given time interval so that said vertical sweep may be operated at a slower rate and the ''''writing'''' of the video signals correspondingly slowed.
Claim 5
Independent Claim
263 words
An apparatus for providing a perspective radar display of terrain in front of an aircraft, comprising, in combination: a. a high resolution rapid scanning radar having a cathode ray tube with a vertical sweep and a video signal input for displaying video return echo signals along the sweep path; b. a storage means having an input connected to receive said video echo signals and an output connected to the video input of said cathode ray tube, said storage means receiving and storing video signals linearly with time received during a first time interval corresponding to the time interval between successive transmitter triggering pulses defining the pulse repetition frequency of said radar; c. storage signal releasing means connected to control the release of the video signals from the storage means to the video input of said cathode ray tube; d. function generating means connected to said storage signal releasing means to release the stored video signals in accord with a given function over a second time interval as measured from the beginning to the end of a vertical sweep; and e. means for supplying a signal to said function generating means proportional to the altitude of said aircraft for varying the form of said function defining the rate of release of the video signals with changes in altitude of the aircraft whereby the video signals are displayed at a faster rate during the later portion of the sweep as compared to an earlier portion to provide a perspective display and whereby a desired perspective display is maintained as the altitude of the aircraft varies.
Claim 6
Independent Claim
263 words
An apparatus for providing a perspective radar display of terrain in front of an aircraft, comprising, in combination: a. a high resolution rapid scanning radar having a cathode ray tube with a vertical sweep and a video signal input for displaying video return echo signals along the sweep path; b. a storage means having an input connected to receive said video echo signals and an output connected to the video input of said cathode ray tube, said storage means receiving and storing video signals linearly with time received during a first time interval corresponding to the time interval between successive transmitter triggering pulses defining the pulse repetition frequency of said radar; c. storage signal releasing means connected to control the release of the video signals from the storage means to the video input of said cathode ray tube; d. function generating means connected to said storage signal releasing means to release the stored video signals in accord with a given function over a second time interval as measured from the beginning to the end of a vertical sweep; and e. means for supplying a signal to said function generating means proportional to the altitude of said aircraft for varying the form of said function defining the rate of release of the video signals with changes in altitude of the aircraft whereby the video signals are displayed at a faster rate during the later portion of the sweep as compared to an earlier portion to provide a perspective display and whereby a desired perspective display is maintained as the altitude of the aircraft varies.
Claim 7
Dependent Claim
26 words
An apparatus according to claim 4, in which the vertical sweep for displaying the video signals is linear and said given function is a hyperbolic function.
Claim 8
Dependent Claim
203 words
An apparatus according to claim 5, in which said storage means includes an analog to digital converter for receiving said video echo signals and converting them to a digital data representation of the signals; a storage memory circuit having an input buffer register receiving for storage said digital data and an output buffer register for releasing the stored digital data; and a digital to analog converter circuit connected between said output buffer register and the video input of said cathode ray tube, said storage signal releasing means comprising a variable frequency clock pulse generator responsive to a voltage signal to provide output pulses to said storage means wherein the rate of pulse generation is porportional to the value of said voltage signal, the hyperbolic function generating means including a linear ramp generator connected to receive a synchronizing pulse corresponding to the starting of the vertical sweep in said cathode ray tube to generate a ramp voltage; an analog multiplier/divider means receiving said ramp voltage and shaping it to provide a hyperbolic voltage signal to the input of said clock pulse generator, said storage means releasing said digital data at a rate proportional to the varying frequency of the output clock pulses supplied thereto.
Claim 9
Dependent Claim
19 words
An apparatus according to claim 6, in which said second time interval is equal to said first Time interval.
References Cited (Backward Citations)
US3653044A
Cited
US3716860A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |