GB650965A - Improvements in apparatus for the measurement of velocities - Google Patents
Improvements in apparatus for the measurement of velocitiesInfo
- Publication number
- GB650965A GB650965A GB74548A GB74548A GB650965A GB 650965 A GB650965 A GB 650965A GB 74548 A GB74548 A GB 74548A GB 74548 A GB74548 A GB 74548A GB 650965 A GB650965 A GB 650965A
- Authority
- GB
- United Kingdom
- Prior art keywords
- frequency
- circuit
- counter
- transmitted
- velocity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/50—Systems of measurement based on relative movement of target
- G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
- G01S13/585—Velocity or trajectory determination systems; Sense-of-movement determination systems processing the video signal in order to evaluate or display the velocity value
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
- G01P3/64—Devices characterised by the determination of the time taken to traverse a fixed distance
- G01P3/66—Devices characterised by the determination of the time taken to traverse a fixed distance using electric or magnetic means
- G01P3/665—Devices characterised by the determination of the time taken to traverse a fixed distance using electric or magnetic means for projectile velocity measurements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
- G01S1/72—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using ultrasonic, sonic or infrasonic waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/50—Systems of measurement based on relative movement of target
- G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
- G01S13/583—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets
Landscapes
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- Multimedia (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
650,965. Radiolocation. PHILIPS ELECTRICAL, Ltd. (Philips Electrical Industries of Australia Pty., Ltd.). Jan. 9, 1948, No. 745. [Class 40 (vii)] A radar system for determining the velocity of a moving object includes means for mixing the signals reflected or re-radiated by the object and the transmitted waves to produce a beat frequency and means to determine the ratio between the beat frequency and the transmitted frequency by counting the number of cycles of a counting frequency equal to a subharmonic (or multiple thereof) of the transmitted frequency in one or more half-cycles of the beat frequency. The invention is of particular value where the time available is short and it does not require the transmitted frequency to have great long-term stability. The actual evaluation of either the beat or the transmitted frequency is unnecessary. In one embodiment a transmitter 1 radiates energy of a frequency determined by frequency-multiplier 2 - fed by oscillator 3. Signals reflected from a moving object 13 are received by a receiver 4 and fed together with the transmitted frequency to a mixer 5. The beat frequency is separated from the output of this mixer by low-pass filter 6 and is then squared by amplifier and clipper circuit 7. The squared waveform is differentiated at 8 and applied to pulse selector 9 which feeds negative pulses only to switch 10 which switches on the counter 11 in response to a first pulse and off in response to the next. A subharmonic of the radiated frequency such as the output of oscillator 3 is fed to electronic counter 11 and the number of cycles of this frequency occurring during the time the counter is effective is measured and indicated. The velocity of the moving object is then the velocity of radio waves divided by (twice the number of cycles counted times the multiplication factor of circuit 2). Circuit 8 is normally biassed off but may be brought into operation by switch 14 which may be closed automatically by some event such as the firing of a gun; it is again rendered inoperative by circuit 10 to avoid the counter being re-triggered. An adjustable delay circuit 12 may be used between the switch 14 and circuit 8. A device 15 may be provided to reset the counter circuit. By using a number of switching arrangements with associated counters operated successively the velocity of an object such as a bullet may be determined at various times during its flight. Such a system provides a means for determining the acceleration or deceleration of a moving object. A responder radiating on a different frequency to that received may be used on the object and the system modified to take into account the frequency change. It is stated that sound or other wave energy may be used in place of radio waves.
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL75425D NL75425C (en) | 1944-06-08 | ||
FR957724D FR957724A (en) | 1944-06-08 | ||
BE478697D BE478697A (en) | 1944-06-08 | ||
US615262A US2524610A (en) | 1944-06-08 | 1945-09-10 | Radiant energy method and apparatus for measuring the velocity of moving bodies |
GB74548A GB650965A (en) | 1948-01-09 | 1948-01-09 | Improvements in apparatus for the measurement of velocities |
DEP26421D DE809824C (en) | 1944-06-08 | 1948-12-24 | Device for determining the speed of moving objects, in which a Doppler frequency is generated by mixing emitted and reflected vibrations |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB74548A GB650965A (en) | 1948-01-09 | 1948-01-09 | Improvements in apparatus for the measurement of velocities |
Publications (1)
Publication Number | Publication Date |
---|---|
GB650965A true GB650965A (en) | 1951-03-07 |
Family
ID=9709778
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB74548A Expired GB650965A (en) | 1944-06-08 | 1948-01-09 | Improvements in apparatus for the measurement of velocities |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB650965A (en) |
-
1948
- 1948-01-09 GB GB74548A patent/GB650965A/en not_active Expired
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