US3781888A
Expired / Lapsed
US
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Digital distance ranging system
Assignee: NARCO AVIONICS Inc 270 COMMERCE DRIVE FORT WASHINGTON PA A CORP OF
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Filing: 1972-10-30
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Granted: 1973-12-25
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Expires: 1992-10-30
Abstract
Abstract A digital distance ranging system, particularly adapted for use in aircraft, wherein incoming pulses are converted into signals representing discrete distance ranges. During the first search cycle (epic) of a distance search, all received pulses are distance-classified within a discrete range and remembered, and during each successive epic the received pulses are distancecompared with the remembered ranges and only repeated ranges are remembered for further comparison. When only one such remembered range remains, it is identified and displayed as the valid range.
Inventors
- 👤 J Bail
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:58
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/08; G01S13/10; G01S13/14; G01S13/16; G01S13/74; G01S13/76; G01S13/78; G01S13/785
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
224 words
Digital apparatus for use in determining distance of a plane from a ground station, said plane being equipped with a transmitter suitable for transmitting DME signals to a ground receiving station, and for receiving and decoding DME signals returned from said ground station, said apparatus comprising: a. timing means, for timing each search epic; b. storage means operatively connected to said timing means, for storing signals representative of the range of such received and decoded signals; c. comparison means, for comparing signals received during a given epic with said representative range signals stored during the prior epic to determine those which have a range coincident with that of one of such prior epic signals, and for coupling to said storage means signals representing such coincidence ranges; d. pass-recirculate means, fOr passing decoded signals directly to said storage means during any epic after an epic when no signals were stored in said storage means, and for allowing only said coincidence signals to be stored in said storage means during epics following an epic where at least one signal is stored in said storage means; e. valid distance means for determining when only one such coincidence signal is stored per epic; and f. means for displaying the distance corresponding to said one coincidence signal, such distance representing the distance of the plane from the ground station.
Claim 2
Dependent Claim
224 words
Digital apparatus for use in determining distance of a plane from a ground station, said plane being equipped with a transmitter suitable for transmitting DME signals to a ground receiving station, and for receiving and decoding DME signals returned from said ground station, said apparatus comprising: a. timing means, for timing each search epic; b. storage means operatively connected to said timing means, for storing signals representative of the range of such received and decoded signals; c. comparison means, for comparing signals received during a given epic with said representative range signals stored during the prior epic to determine those which have a range coincident with that of one of such prior epic signals, and for coupling to said storage means signals representing such coincidence ranges; d. pass-recirculate means, fOr passing decoded signals directly to said storage means during any epic after an epic when no signals were stored in said storage means, and for allowing only said coincidence signals to be stored in said storage means during epics following an epic where at least one signal is stored in said storage means; e. valid distance means for determining when only one such coincidence signal is stored per epic; and f. means for displaying the distance corresponding to said one coincidence signal, such distance representing the distance of the plane from the ground station.
Claim 3
Dependent Claim
29 words
The apparatus as described in claim 1, wherein said timing means comprises a clock generator and a counter which counts the clock pulses produced by said generator each epic.
Claim 4
Dependent Claim
23 words
The apparatus as described in claim 2, comprising epic gate means for gating clock pulses to said counter only during each search epic.
Claim 5
Dependent Claim
41 words
The apparatus as described in claim 3 wherein said counter provides a binary coded decimal output, and produces an end of search signal which signals the end of each search after the counter has received a predetermined number of clock pulses.
Claim 6
Dependent Claim
47 words
The apparatus as described in claim 1 wherein said storage means is a shift register, and said shift register is connected to said counter to receive shift signals which shift all signals stored therein during a given epic out of the register during the next succeeding epic.
Claim 7
Dependent Claim
46 words
The apparatus as described in claim 2 wherein said valid distance means performs the function of enabling the display means during the next epic following the determination of said only one coincidence signal, passing a valid distance pulse which is coincident with said one coincidence signal.
Claim 8
Dependent Claim
44 words
The apparatus as described in claim 6 wherein said display means comprises latches which are connected to said valid distance means and which receive inputs from said counter, and which hold the count of said counter at the time of said valid distance pulse.
Claim 9
Dependent Claim
119 words
In a DME aircraft receiver, a method of separating return DME signals of such aircraft from other signals, and of determining the distance of such aircraft from the ground station from which such signals are returned, comprising: a. during a first epic, storing all received signals in time relationship relative to the time of transmittal of the DME signal from the aircraft; b. in each successive epic after at least one signal has been stored, storing in time relationship only received signals in time coincidence with signals stored during the prior epic; and, c. identifying when only one such coincidence signal is stored during an epic, and deriving the aircraft distance from the time of such one stored signal.
Claim 10
Dependent Claim
119 words
In a DME aircraft receiver, a method of separating return DME signals of such aircraft from other signals, and of determining the distance of such aircraft from the ground station from which such signals are returned, comprising: a. during a first epic, storing all received signals in time relationship relative to the time of transmittal of the DME signal from the aircraft; b. in each successive epic after at least one signal has been stored, storing in time relationship only received signals in time coincidence with signals stored during the prior epic; and, c. identifying when only one such coincidence signal is stored during an epic, and deriving the aircraft distance from the time of such one stored signal.
Claim 11
Dependent Claim
190 words
Digital apparatus for determining the distance of a plane from a ground station, said plane being equipped with a transmitter suitable for transmitting DME signals to a ground receiving station, and for receiving and decoding DME signals returned from said ground station, said apparatus comprising: a. memory means adapted to store signal representations of the time relationship of such signals received during an epic; b. first logic means for gating into said memory means all of the received signals during the search epic following a prior epic when no signals are stored in said memory means; c. second logic means, operative during each successive epic after the first epic when at least one signal is stored in said memory means, to gate into said memory means only signals in relative time coincidence with the signal representations stored in the prior epic; and d. third logic means, for identifying when only one signal representation is stored in said memory means during an epic, and for deriving the distance of the plane from the time of occurrence during the succeeding epic of a signal in time coincidence with such one signal representation.
Claim 12
Dependent Claim
190 words
Digital apparatus for determining the distance of a plane from a ground station, said plane being equipped with a transmitter suitable for transmitting DME signals to a ground receiving station, and for receiving and decoding DME signals returned from said ground station, said apparatus comprising: a. memory means adapted to store signal representations of the time relationship of such signals received during an epic; b. first logic means for gating into said memory means all of the received signals during the search epic following a prior epic when no signals are stored in said memory means; c. second logic means, operative during each successive epic after the first epic when at least one signal is stored in said memory means, to gate into said memory means only signals in relative time coincidence with the signal representations stored in the prior epic; and d. third logic means, for identifying when only one signal representation is stored in said memory means during an epic, and for deriving the distance of the plane from the time of occurrence during the succeeding epic of a signal in time coincidence with such one signal representation.
Claim 13
Dependent Claim
40 words
The method as described in claim 9, further comprising the steps of determining when no siGnals are stored during a search epic, and repeating the steps as set forth in claim 9 and in the sequence as there set forth.
Claim 14
Dependent Claim
185 words
In an aircraft equipped to transmit DME signals to a ground station and operate on signals returned therefrom, the method of determining the distance of such aircraft from such ground station, comprising: a. decoding signals received from said ground station to obtain video pulses; b. gating said pulses during search epics following each transmitted DME signal; c. during a search epic when no history of prior distance signals is available in the receiver, storing signal representations of all said gated signals in relative time relationship; d. in the next epic after an epic during which at least one signal representation has been stored, reading signal representations stored from the prior epic in time reference to the transmitted signal of said next epic, and comparing said read signal representations with said gated signals, and storing only those gated signals in time coincidence with one of said read signals; e. repeating the steps of reading, comparing and storing until only one such time coincidence is stored during an epic, and deriving the distance of the plane to the ground station from the time of such one coincidence.
Claim 15
Dependent Claim
185 words
In an aircraft equipped to transmit DME signals to a ground station and operate on signals returned therefrom, the method of determining the distance of such aircraft from such ground station, comprising: a. decoding signals received from said ground station to obtain video pulses; b. gating said pulses during search epics following each transmitted DME signal; c. during a search epic when no history of prior distance signals is available in the receiver, storing signal representations of all said gated signals in relative time relationship; d. in the next epic after an epic during which at least one signal representation has been stored, reading signal representations stored from the prior epic in time reference to the transmitted signal of said next epic, and comparing said read signal representations with said gated signals, and storing only those gated signals in time coincidence with one of said read signals; e. repeating the steps of reading, comparing and storing until only one such time coincidence is stored during an epic, and deriving the distance of the plane to the ground station from the time of such one coincidence.
Claim 16
Dependent Claim
82 words
The method as described in claim 11, wherein during said first search epic said gated pulses are stored in a shift register, and during successive epics, said stored representations are read out and connected to a first input terminal of a coincidence circuit, and said gated pulses are connected to a second input terminal of such coincidence circuit, such coincidence circuit passing a gated pulse only when it coincides in time relationship with a corresponding gated pulse during the prior search epic.
Claim 17
Dependent Claim
141 words
Digital apparatus for use in determining the distance of an object from a remote station, said object being equipped to transmit pulse signals to said remote station and receive and decode said signals when returned from said remote station, said apparatus comprising: a. memory means for storing signals representing ranges of pulses received during an epic; b. comparison means for comparing the ranges of decoded pulses received during an epic with the range representations stored from the prior epic; c. logic means for limiting the range signals stored in said memory means each epic to those representing the ranges of pulses received during such epic which coincide with a range stored during the prior epic; d. means for determining when only one range signal is stored during an epic; and e. means for displaying an output corresponding to such one range.
Claim 18
Dependent Claim
141 words
Digital apparatus for use in determining the distance of an object from a remote station, said object being equipped to transmit pulse signals to said remote station and receive and decode said signals when returned from said remote station, said apparatus comprising: a. memory means for storing signals representing ranges of pulses received during an epic; b. comparison means for comparing the ranges of decoded pulses received during an epic with the range representations stored from the prior epic; c. logic means for limiting the range signals stored in said memory means each epic to those representing the ranges of pulses received during such epic which coincide with a range stored during the prior epic; d. means for determining when only one range signal is stored during an epic; and e. means for displaying an output corresponding to such one range.
Claim 19
Dependent Claim
134 words
Digital apparatus for use in determining the distance of an object from a remote station, said object being equipped to transmit pulse signals to said remote station and receive and decode said signals when returned from said remote station, said apparatus comprising: a. memory means for storing signals representing ranges corresponding to received pulses; b. signal control means operative during successive search epics for limiting, during said each such successive epic, the input to said memory means to signals each of which represents a range corresponding to a pulse received both during the prior epic and during the next following epic; c. logic means for determining when only one range signal is stored during one of said next following epics; and d. means for displaying an output corresponding to said only one range signal.
Claim 20
Dependent Claim
134 words
Digital apparatus for use in determining the distance of an object from a remote station, said object being equipped to transmit pulse signals to said remote station and receive and decode said signals when returned from said remote station, said apparatus comprising: a. memory means for storing signals representing ranges corresponding to received pulses; b. signal control means operative during successive search epics for limiting, during said each such successive epic, the input to said memory means to signals each of which represents a range corresponding to a pulse received both during the prior epic and during the next following epic; c. logic means for determining when only one range signal is stored during one of said next following epics; and d. means for displaying an output corresponding to said only one range signal.
Claim 21
Dependent Claim
44 words
The apparatus as described in claim 14 wherein said memory means comprises a shift register in combination with a shift signal generator, said range signals being stored in bins of said counter and being shifted through said counter by signals from said shift generator.
Claim 22
Dependent Claim
110 words
The apparatus as described in claim 15 wherein said signal control means performs the following functions: a. when no range signals have bee stored in said memory means during a prior epic, pass all received pulses during the next epic into said memory means for storage; and b. when one or more range signals have been stored in said memroy means during a prior epic, the pulses received during the next epic are compared with the range signals stored in said memory means during said prior epic, and only pulses having a range coincident with that of one of the stored signals are passed into said memory means for storage.
Claim 23
Independent Claim
164 words
A method for determining the distance of an object from a remote station, said object being equipped to transmit pulse signals to said remote station and receive and decode signals returned from said remote station, comprising: a. during a first epic, storing signals in a memory, which signals are representative of the ranges corresponding to the time of receipt of decoded signals relative to the start of said first epic; b. during the next epic, reading out said stored range signals in a time relationship referenced to the start of said succeeding epic; c. comparing the time of said read-out signals and the signals received during said succeeding epic, and storing only signals representative of such received signals which are time coincident with a read-out signal; d. repeating during following epics the steps of reading out, comparing, and storing coincidence signals, until only one such coincidence signal is stored during an epic; and e. displaying a range signal corresponding to said one coincidence signal.
Claim 24
Independent Claim
164 words
A method for determining the distance of an object from a remote station, said object being equipped to transmit pulse signals to said remote station and receive and decode signals returned from said remote station, comprising: a. during a first epic, storing signals in a memory, which signals are representative of the ranges corresponding to the time of receipt of decoded signals relative to the start of said first epic; b. during the next epic, reading out said stored range signals in a time relationship referenced to the start of said succeeding epic; c. comparing the time of said read-out signals and the signals received during said succeeding epic, and storing only signals representative of such received signals which are time coincident with a read-out signal; d. repeating during following epics the steps of reading out, comparing, and storing coincidence signals, until only one such coincidence signal is stored during an epic; and e. displaying a range signal corresponding to said one coincidence signal.
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) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |