GB543943A - Improvements in frequency-modulated radio altimeters - Google Patents

Improvements in frequency-modulated radio altimeters

Info

Publication number
GB543943A
GB543943A GB13698/40A GB1369840A GB543943A GB 543943 A GB543943 A GB 543943A GB 13698/40 A GB13698/40 A GB 13698/40A GB 1369840 A GB1369840 A GB 1369840A GB 543943 A GB543943 A GB 543943A
Authority
GB
United Kingdom
Prior art keywords
frequency
amplifier
altitude
voltage
motor
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
Application number
GB13698/40A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BAE Systems Electronics Ltd
Original Assignee
Marconis Wireless Telegraph Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Marconis Wireless Telegraph Co Ltd filed Critical Marconis Wireless Telegraph Co Ltd
Publication of GB543943A publication Critical patent/GB543943A/en
Expired legal-status Critical Current

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
    • 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
    • G01S1/02—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 radio waves

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Transmitters (AREA)

Abstract

543,943. Radio echo apparatus condensers. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Aug. 31, 1940, No. 13698. Convention date, Sept 1, 1939. [Class 37] In a frequency modulated radio altimeter the modulation band is made inversely proportional to the altitude so as to improve the ratio of signal to amplifier noise by decreasing the modulation band width as the signal strength diminishes. In the arrangement shown in Fig. 1 a heterodyne receiver 1 is connected through an amplifier 3 to a frequency meter 5 of the electronic type. The frequency meter output is connected to a D.C. amplifier 7 which controls the gain of a low frequency amplifier 9. The input of the low frequency amplifier is connected to a low frequency oscillator 11 and the amplifier output is applied to a frequency modulator 13 which is connected to a radio transmitter 15 and an A.C. voltmeter 17. The frequency modulator 13 may be of the variable capacitor type shown in Fig. 3. A pair of stationary capacitor plates 19, 21 is secured by insulating posts 39 to a frame 23 on which is mounted an electromechanical motor 25. The movable element of the motor reciprocates vertically and carries a movable capacitor plate 29. The resulting variation in capacitance is applied to the transmitter to vary its instantaneous frequency. Alternatively inductive variation may be used and may be applied by means of a motor or electronically. The altitude is measured in terms of the A.C. voltage or current applied to the frequency modulator. The A.C. voltmeter 17 may be calibrated directly in altitudes. Voltage or current corresponding to the altitude may alternatively be measured at other points in the system such as the controlling bias or voltage.
GB13698/40A 1939-09-01 1940-08-31 Improvements in frequency-modulated radio altimeters Expired GB543943A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US293128A US2257830A (en) 1939-09-01 1939-09-01 Frequency-modulated radio altimeter

Publications (1)

Publication Number Publication Date
GB543943A true GB543943A (en) 1942-03-20

Family

ID=23127771

Family Applications (1)

Application Number Title Priority Date Filing Date
GB13698/40A Expired GB543943A (en) 1939-09-01 1940-08-31 Improvements in frequency-modulated radio altimeters

Country Status (3)

Country Link
US (1) US2257830A (en)
GB (1) GB543943A (en)
NL (1) NL60726C (en)

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL60855C (en) * 1942-05-01
FR897437A (en) * 1942-06-10 1945-03-21 Philips Nv Apomecometer, in particular altimeter
US2453169A (en) * 1943-04-10 1948-11-09 Sperry Corp Radio ground clearance indicator
NL136631B (en) * 1944-03-20
US2598702A (en) * 1945-01-19 1952-06-03 Jr Martin V Kiebert Sweep compression for use of fm range equipment
US2462531A (en) * 1945-05-22 1949-02-22 Minshall Burton Musical vibration translating unit
US2543782A (en) * 1945-05-26 1951-03-06 Jr Martin V Kiebert Frequency modulated radio-type distance measuring device
US2466534A (en) * 1945-07-30 1949-04-05 Rca Corp Radar glide path control system
US2573329A (en) * 1946-05-24 1951-10-30 Well Surveys Inc Capacitative commutator
US2537593A (en) * 1947-02-26 1951-01-09 Rca Corp Frequency modulation altimeter and range finder
US2658173A (en) * 1949-11-30 1953-11-03 Honeywell Regulator Co Vibrating condenser converter
US2632791A (en) * 1949-11-30 1953-03-24 Honeywell Regulator Co Vibratory condenser converter
US2736891A (en) * 1952-02-08 1956-02-28 Philco Corp Method of and means for measuring distance
US3112481A (en) * 1957-12-20 1963-11-26 Litton Systems Inc Continuous wave frequency modulation distance measuring apparatus
IT1102727B (en) * 1978-03-02 1985-10-07 Autovox Spa DETECTION DEVICE FOR THE ROTATION STATUS OF A SHAFT, IN PARTICULAR FOR TURNTABLES
US5869747A (en) * 1996-05-22 1999-02-09 William H. Hulsman Food container internal pressure analysis

Also Published As

Publication number Publication date
US2257830A (en) 1941-10-07
NL60726C (en)

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