US3680122A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pilot warning indicator system utilizing a transmission of signals within the absorption band of the oxygen spectrum
Assignee: Control Data Corp
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Filing: 1970-03-13
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Granted: 1972-07-25
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Expires: 1990-03-13
Abstract
Abstract A proximity indicator system for aircraft which includes a radio signal transmitter having a predetermined output frequency range within an absorption band of the spectrum of a major invariable constituent of the atmosphere. A transmit antenna, which may be rotatable, is employed to propagate an output frequency within the predetermined range which may be responsive to variations in ambient atmosphere density and hence altitude. A rotatable antenna is connected to a radio receiver which has a predetermined amplitude threshold receiving level and is attuned to at least a portion of the output frequency range. A display is connected to the receiver to indicate reception of a signal and, optionally its direction. The output signal may be monitored by a receiver which contains a modulating circuit to compare a received signal with the monitored signal, the resultant being representative of any altitude differential which may exist between the respective signal sources. Resultants which represent more than a predetermined maximum differential will be rejected. A rotatable transmit antenna may supply bearing information regarding the output signal to a modulating circuit simultaneously with a signal representing air speed, whereby the output signal is impressed with a bearing velocity component. The output signal is monitored and compared with a similarly encoded received signal to reject information derived from a receding source (or other sources not representing a near term collision threat).
Inventors
- 👤 Walton Graham
- 👤 Robert R Keegan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:01
CPC Classifications
G; G01; G01S; G01S11/00; G01S11/02; G01S11/06
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
97 words
A proximity indicator system comprising: a radio signal transmitter having a predetermined output frequency range within an absorption band of the spectrum of a major invariable constituent of the atmosphere; a transmitting antenna connected to receive the output of said transmitter; a receiving antenna; a radio receiver having a predetermined amplitude threshold receiving level attuned to at least a portion of said output frequency range and connected to receive the signal from said receiving antenna; and a display connected to said receiver output to indicate reception of a signal at an amplitude above said predetermined threshold level.
Claim 2
Dependent Claim
97 words
A proximity indicator system comprising: a radio signal transmitter having a predetermined output frequency range within an absorption band of the spectrum of a major invariable constituent of the atmosphere; a transmitting antenna connected to receive the output of said transmitter; a receiving antenna; a radio receiver having a predetermined amplitude threshold receiving level attuned to at least a portion of said output frequency range and connected to receive the signal from said receiving antenna; and a display connected to said receiver output to indicate reception of a signal at an amplitude above said predetermined threshold level.
Claim 3
Dependent Claim
149 words
An airborne proximity indicator system comprising: a low power radio signal transmitter having a predetermined output frequency range for which the sea level absorption of a constituent of the atmosphere other than water is at least 3 dB per kilometer; an airborne transmitting antenna connected to receive the output of said transmitter; a horizontally scanning airborne receiving antenna; an airborne radio receiver tunable to at least a portion of said output frequency range and connected to detect signals from said receiving antenna which have an amplitude exceeding the threshold level of said receiver; and an indicator connected to the output of said receiver to indicate reception of certain ones of signals detected by said receiver; whereby signals originating from aircraft beyond the distance of unaided visibility are generally attenuated sufficiently to be undetected while signals from close, possibly hazardous, aircraft are reliably detected and indicated under good visibility conditions.
Claim 4
Dependent Claim
149 words
An airborne proximity indicator system comprising: a low power radio signal transmitter having a predetermined output frequency range for which the sea level absorption of a constituent of the atmosphere other than water is at least 3 dB per kilometer; an airborne transmitting antenna connected to receive the output of said transmitter; a horizontally scanning airborne receiving antenna; an airborne radio receiver tunable to at least a portion of said output frequency range and connected to detect signals from said receiving antenna which have an amplitude exceeding the threshold level of said receiver; and an indicator connected to the output of said receiver to indicate reception of certain ones of signals detected by said receiver; whereby signals originating from aircraft beyond the distance of unaided visibility are generally attenuated sufficiently to be undetected while signals from close, possibly hazardous, aircraft are reliably detected and indicated under good visibility conditions.
Claim 5
Dependent Claim
62 words
Apparatus as claimed in claim 2 further including means for communicating the altitude of the transmitting aircraft comprising: means for generating a signal representing the altitude of said transmitting aircraft; means for modulating transmissions from said transmitting antenna in accordance with said altitude signal; and means for receiving and demodulating said transmission to produce a signal corresponding to said transmitting aircraft altitude.
Claim 6
Dependent Claim
29 words
Apparatus as claimed in claim 3 wherein said antennas are rotating antennas and the rotational motion of said transmit antenna is asynchronous with the motion of said receive antenna.
Claim 7
Dependent Claim
29 words
Apparatus as claimed in claim 2 wherein said antennas are rotating antennas and the rotational motion of said transmit antenna is asynchronous with the motion of said receive antenna.
Claim 8
Dependent Claim
69 words
Apparatus as claimed in claim 5 further including means for communicating an azimuthal component of the velocity of the transmitting aircraft comprising: means for generating a signal representing the instantaneous azimuthal bearing angle of said transmitting antenna; means for computing from said bearing angle and the aircraft total velocity the azimuthal velocity component; and means for modulating transmissions from said transmitting antenna in accordance with said azimuthal velocity component.
Claim 9
Dependent Claim
23 words
Apparatus as claimed in claim 6 wherein said frequency range has an absorption at sea level between 5 and 10 dB per kilometer.
Claim 10
Dependent Claim
23 words
Apparatus as claimed in claim 2 wherein said frequency range has an absorption at sea level between 5 and 10 dB per kilometer.
Claim 11
Dependent Claim
115 words
An airborne proximity indicator system comprising: a radio signal transmitter having a predetermined output frequency range within an absorption band of the spectrum of a major invariable constituent of the atmosphere; a horizontally scanning airborne transmitting antenna connected to receive the output of said transmitter; a horizontally scanning airborne receiving antenna for receiving transmissions from said transmitting antenna; an airborne radio receiver tunable to a least a portion of said output frequency range and connected to detect signals from said receiving antenna which have an amplitude exceeding the threshold level of said receiver; and an indicator connected to the output of said receiver to indicate reception of certain ones of signals detected by said receiver.
Claim 12
Dependent Claim
115 words
An airborne proximity indicator system comprising: a radio signal transmitter having a predetermined output frequency range within an absorption band of the spectrum of a major invariable constituent of the atmosphere; a horizontally scanning airborne transmitting antenna connected to receive the output of said transmitter; a horizontally scanning airborne receiving antenna for receiving transmissions from said transmitting antenna; an airborne radio receiver tunable to a least a portion of said output frequency range and connected to detect signals from said receiving antenna which have an amplitude exceeding the threshold level of said receiver; and an indicator connected to the output of said receiver to indicate reception of certain ones of signals detected by said receiver.
Claim 13
Dependent Claim
69 words
Apparatus as claimed in claim 9 further including means for communicating an azimuthal component of the velocity of the transmitting aircraft comprising: means for generating a signal representing the instantaneous azimuthal bearing angle of said transmitting antenna; means for computing from said bearing angle and the aircraft total velocity the azimuthal velocity component; and means for modulating transmissions from said transmitting antenna in accordance with said azimuthal velocity component.
Claim 14
Dependent Claim
22 words
Apparatus as claimed in claim 10 wherein the scan of said transmit antenna is asynchronous with the scan of said receive antenna.
Claim 15
Dependent Claim
62 words
Apparatus as claimed in claim 9 further including means for communicating the altitude of the transmitting aircraft comprising: means for generating a signal representing the altitude of said transmitting aircraft; means for modulating transmissions from said transmitting antenna in accordance with said altitude signal; and means for receiving and demodulating said transmission to produce a signal corresponding to said transmitting aircraft altitude.
Claim 16
Dependent Claim
23 words
Apparatus as claimed in claim 12 wherein said frequency range has an absorption at sea level between 5 and 10 dB per kilometer.
Claim 17
Dependent Claim
125 words
An airborne proximity indicator system comprisIng: a radio signal transmitter having a predetermined output frequency range within an absorption band of the spectrum of a major invariable constituent of the atmosphere; a horizontally scanning transmitting antenna connected to receive the output of said transmitter; a horizontally scanning airborne receiving antenna having a scan rate differing by at least a factor of ten from that of said transmitting antenna; an airborne radio receiver tunable to at least a portion of said output frequency range and connected to detect signals from said receiving antenna which have an amplitude exceeding the threshold level of said receiver; and an indicator connected to the output of said receiver to indicate reception of certain ones of signals detected by said receiver.
Claim 18
Dependent Claim
125 words
An airborne proximity indicator system comprisIng: a radio signal transmitter having a predetermined output frequency range within an absorption band of the spectrum of a major invariable constituent of the atmosphere; a horizontally scanning transmitting antenna connected to receive the output of said transmitter; a horizontally scanning airborne receiving antenna having a scan rate differing by at least a factor of ten from that of said transmitting antenna; an airborne radio receiver tunable to at least a portion of said output frequency range and connected to detect signals from said receiving antenna which have an amplitude exceeding the threshold level of said receiver; and an indicator connected to the output of said receiver to indicate reception of certain ones of signals detected by said receiver.
Claim 19
Dependent Claim
62 words
Apparatus as claimed in claim 14 further including means for communicating the altitude of the transmitting antenna comprising: means for generating a signal representing the altitude of said transmitting aircraft; means for modulating transmissions from said transmitting antenna in accordance with said altitude signal, and means for receiving and demodulating said transmission to produce a signal corresponding to said transmitting aircraft altitude.
Claim 20
Dependent Claim
105 words
An airborne proximity indicator system comprising: a radio signal transmitter having a predetermined output frequency range within an absorption band of the spectrum of a major invariable constituent of the atmosphere; a transmitting antenna connected to receive the output of said transmitter; a horizontally scanning airborne receiving antenna; an airborne radio receiver tunable to at least a portion of said output frequency range and connected to detect signals from said receiving antenna which have an amplitude exceeding the threshold level of said receiver; and an indicator connected to the output of said receiver to indicate reception of certain ones of signals detected by said receiver.
Claim 21
Dependent Claim
105 words
An airborne proximity indicator system comprising: a radio signal transmitter having a predetermined output frequency range within an absorption band of the spectrum of a major invariable constituent of the atmosphere; a transmitting antenna connected to receive the output of said transmitter; a horizontally scanning airborne receiving antenna; an airborne radio receiver tunable to at least a portion of said output frequency range and connected to detect signals from said receiving antenna which have an amplitude exceeding the threshold level of said receiver; and an indicator connected to the output of said receiver to indicate reception of certain ones of signals detected by said receiver.
Claim 22
Dependent Claim
62 words
Apparatus as claimed in claim 16 further including means for communicating the altitude of the transmitting aircraft comprising: means for generating a signal representing the altitude of said transmitting aircraft; means for modulating transmissions from said transmitting antenna in accordance with said altitude signal; and means for receiving and demodulating said transmission to produce a signal corresponding to said transmitting aircraft altitude.
Claim 23
Dependent Claim
13 words
Apparatus as claimed in claim 16 wherein said said antennas are rotating antennas.
Claim 24
Dependent Claim
69 words
Apparatus as claimed in claim 18 further including means for communicating an azimuthal component of the velocity of the transmitting aircraft comprising: means for generating a signal representing the instantaneous azimuthal bearing angle of said transmitting antenna; means for computing from said bearing angle and the aircraft total velocity the azimuthal velocity component; and means for modulating transmissions from said transmitting antenna in accordance with said azimuthal velocity component.
Claim 25
Dependent Claim
23 words
Apparatus as claimed in claim 16 wherein said frequency range has an absorption at sea level between 5 and 10 dB per kilometer.
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |