US4010465A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Channel encoding for distance measurement equipment
Assignee: International Telephone and Telegraph Corp
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Filing: 1975-04-04
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Granted: 1977-03-01
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Expires: 1995-04-04
Abstract
Abstract An adapter is provided for insertion between a conventional DME airborne interrogator and antenna. The adpater converts conventional interrogations into phase-coded or amplitude coded signals which are received by new Microwave Landing System (MLS) transponders. Each transponder will process interrogations having the correct code and frequency and will respond with precision reply signals. The precision replies are then received by the airborne equipment, converted back to standard reply pulses and processed to provide distance measurement. Also provided is a new transponder for use at MLS sites.
Inventors
- 👤 Sven H. Dodington
- 👤 Jesse S. LeGrand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:13
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/76; G01S13/78; G01S13/785; G01S13/787
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
136 words
An Apparatus for generating interrogation signals for use with airborne equipment of the type which transmits interrogation signals containing at least one pulse of a first type to a ground beacon, said beacon of a type which responds to interrogation signals of a second type with reply signals of said second type, and wherein said airborne equipment processes reply signals of said first type, said airborne equipment including a transmitter, a receiver, an interrogator and an antenna, said apparatus comprising: means for detecting said first type of interrogation signal; means for converting said at least one pulse to at least one second pulse having a reduced amplitude; means for generating a coded signal; and means for modulating said at least one second pulse with said coded signal to produce an interrogation signal of said second type.
Claim 2
Independent Claim
136 words
An Apparatus for generating interrogation signals for use with airborne equipment of the type which transmits interrogation signals containing at least one pulse of a first type to a ground beacon, said beacon of a type which responds to interrogation signals of a second type with reply signals of said second type, and wherein said airborne equipment processes reply signals of said first type, said airborne equipment including a transmitter, a receiver, an interrogator and an antenna, said apparatus comprising: means for detecting said first type of interrogation signal; means for converting said at least one pulse to at least one second pulse having a reduced amplitude; means for generating a coded signal; and means for modulating said at least one second pulse with said coded signal to produce an interrogation signal of said second type.
Claim 3
Dependent Claim
54 words
An apparatus according to claim 1 wherein said means for generating includes: a shift register; a read only memory for storing a plurality of codes having an output coupled to said shift register; and code selection means for accessing a particular one of said plurality of codes and applying it to said shift register.
Claim 4
Dependent Claim
32 words
An apparatus according to claim 1 wherein said modulating means comprises an amplitude modulator having as an input said at least one second pulse and the output of said means for generating.
Claim 5
Dependent Claim
32 words
An apparatus according to claim 1 wherein said means for modulating comprises a phase modulator having as inputs said at least one second pulse and the output of said means for generating.
Claim 6
Independent Claim
160 words
An apparatus for use with airborne equipment of the type which transmits interrogation signals comprising at least one pulse of a first type to a ground beacon, said beacon of a type which responds to interrogation signals of a second type with reply signals of said second type and wherein said equipment processes reply signals of said first type, said airborne equipment including a transmitter, a receiver, an interrogator and an antenna, said apparatus comprising: means for detecting said first type interrogation signal; means for converting said at least one pulse to at least one second pulse having a reduced amplitude; means for generating a coded signal; means for modulating said at least one second pulse with said coded signal to produce an interrogation signal of said second type; means for receiving said reply signals of said second type; and means for converting said reply signals of said second type to said first type for processing in said airborne equipment.
Claim 7
Independent Claim
160 words
An apparatus for use with airborne equipment of the type which transmits interrogation signals comprising at least one pulse of a first type to a ground beacon, said beacon of a type which responds to interrogation signals of a second type with reply signals of said second type and wherein said equipment processes reply signals of said first type, said airborne equipment including a transmitter, a receiver, an interrogator and an antenna, said apparatus comprising: means for detecting said first type interrogation signal; means for converting said at least one pulse to at least one second pulse having a reduced amplitude; means for generating a coded signal; means for modulating said at least one second pulse with said coded signal to produce an interrogation signal of said second type; means for receiving said reply signals of said second type; and means for converting said reply signals of said second type to said first type for processing in said airborne equipment.
Claim 8
Dependent Claim
100 words
In a distance measuring system, a beacon for receiving coded interrogation signals, processing interrogation signals having a correct code and generating a reply signal in response to said interrogation signals comprising: means for detecting the presence of an interrogation signal; means for decoding said interrogation signal to determine if it is one to which a response should be made; means for determining the frequency of said interrogation signal to determine if it is one to which a response should be made; and means for generating a coded reply signal in response to an interrogation having a correct code and frequency.
Claim 9
Dependent Claim
100 words
In a distance measuring system, a beacon for receiving coded interrogation signals, processing interrogation signals having a correct code and generating a reply signal in response to said interrogation signals comprising: means for detecting the presence of an interrogation signal; means for decoding said interrogation signal to determine if it is one to which a response should be made; means for determining the frequency of said interrogation signal to determine if it is one to which a response should be made; and means for generating a coded reply signal in response to an interrogation having a correct code and frequency.
Claim 10
Dependent Claim
15 words
A beacon according to claim 6 wherein said means for decoding includes a phase decoder.
Claim 11
Dependent Claim
15 words
A beacon according to claim 6 wherein said means for decoding includes an amplitude decoder.
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) | 1980-02-29 | 1980-08-30 | 1981-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-29 | 1984-08-30 | 1985-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-29 | 1988-08-30 | 1989-03-01 | $7700.00 | Window Closed / Lapsed |