Connect public, paid and private patent data with Google Patents Public Datasets

Satellite-based collision avoidance system and method therefor

Info

Publication number
WO1998043107A1
WO1998043107A1 PCT/US1998/006177 US9806177W WO1998043107A1 WO 1998043107 A1 WO1998043107 A1 WO 1998043107A1 US 9806177 W US9806177 W US 9806177W WO 1998043107 A1 WO1998043107 A1 WO 1998043107A1
Authority
WO
Grant status
Application
Patent type
Prior art keywords
aircraft
data
time
gps
pressure
Prior art date
Application number
PCT/US1998/006177
Other languages
French (fr)
Inventor
Geoffrey S. M. Hedrick
Original Assignee
Hedrick Geoffrey S M
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

Links

Classifications

    • GPHYSICS
    • G08SIGNALLING
    • G08GTRAFFIC CONTROL SYSTEMS
    • G08G5/00Traffic control systems for aircraft, e.g. air-traffic control [ATC]
    • G08G5/0095Aspects of air-traffic control not provided for in the other subgroups of this main group
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01CMEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C5/00Measuring height; Measuring distances transverse to line of sight; Levelling between separated points; Surveyors' levels
    • G01C5/005Measuring height; Measuring distances transverse to line of sight; Levelling between separated points; Surveyors' levels altimeters for aircraft
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S19/00Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/38Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system
    • G01S19/39Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S5/00Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S19/00Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/38Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system
    • G01S19/39Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/42Determining position
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S2205/00Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S2205/001Transmission of position information to remote stations
    • G01S2205/002Transmission of position information to remote stations for traffic control, mobile tracking, guidance, surveillance or anti-collision
    • G01S2205/005Transmission of position information to remote stations for traffic control, mobile tracking, guidance, surveillance or anti-collision for aircraft positioning relative to other aircraft

Abstract

An aircraft collision avoidance method, including the steps of determining geopotential heights of a first (10) and a second (14) aircraft at substantially the same instant of time using a satellite-based position determining device disposed on each of the first (10) and second (14) aircraft; pausing for a time period t1, then transmitting data representing the geopotential height of the first aircraft from the first aircraft pausing for a time period t2, then transmitting data representing the geopotential height of the second aircraft from the second aircraft; receiving data from one of the first and second aircraft; estimating a vertical separation distance between the first and second aircraft at substantially the same instant of time using the received data by forming a difference between the geopotential heights of the first and the second aircraft; and reporting a warning to a pilot or an automated flight control computer (22) if the estimated vertical separation distance is below a threshold value.

Description

Satellite-Based Collision Avoidance System And Method Therefor

BACKGROUND OF THE INVENTION

1. Field of the Invention The present invention relates to collision avoidance systems and, more particularly, to an aircraft collision avoidance system which utilizes the Global Positioning Satellites and aircraft barometric altimeters.

2. Description of the Related Art Recent changes in aircraft flight regulations for flight operations in the North Atlantic Minimum Navigation Performance Specifications (NAT/MNPS) airspace have reduced the minimum allowable vertical distance between two aircraft flying through this airspace from 2,000 feet to 1,000 feet for operation between specified flight levels, currently, Flight Level (FL) 290 and FL 410, inclusive. The Reduced Vertical Separation Minimum, or RVSM, will allow more aircraft to fly more optimal profiles and increase the air traffic capacity through this airspace.

As more aircraft fly through a given airspace, the probability of near misses could also increase due to, for example, inaccurate or malfunctioned altitude control systems. Thus, it is more important than ever that the aircraft flying through the RVSM airspace be equipped with a dynamic collision avoidance system. Various collision avoidance systems have been developed over the years. An example of such a system is disclosed in U.S. Patent No. 4,293,857 to Baldwin. Baldwin teaches an aircraft avoidance system which utilizes a reference navigational ground station to enable a first aircraft to determine its own location and a reference ground-based air surveillance radar to determine the location, velocity, course and altitude of a second aircraft for potential collision. A disadvantage of this system is that a multitude of expensive navigational ground stations and surveillance radars must be installed along the flight paths of aircraft.

U.S. Patent No. 4,317,119 to Alvarez discloses a standalone collision avoidance system for installation on a passenger jet. Alvarez's system employs a bistatic radar antenna system with mechanically driven antennas for scanning the space ahead of the aircraft. A disadvantage of this system is that the mechanical drive mechanism for the antennas is prone to wear and tear and/or mechanical jamming. SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a low-cost, reliable dynamic electronic collision avoidance system for aircraft.

Another object of the invention is to provide a method for dynamically monitoring an RVSM airspace by the aircraft flying therethrough .

In accordance with an embodiment of the present invention, an aircraft collision avoidance method, includes the steps of (1) determining geopotential or absolute geometric heights of a first and a second aircraft at a substantially the same instant of time using a satellite-based position determining device disposed on each of the first and the second aircraft; (2) pausing for a time period t_ then transmitting data representing the geopotential height of the first aircraft from the first aircraft to the second aircraft; (3) pausing for a time period t2 then transmitting data representing the geopotential height of the second aircraft from the second aircraft to the second aircraft to the first aircraft; (4) receiving the data from one of the first and second aircraft by another one of the first and second aircraft; (5) estimating a vertical separation distance between the first and the second aircraft at said substantially the same instant of time using the received data by forming a difference between the geopotential heights of the first and the second aircraft; and (6) reporting a warning to a pilot or an automated flight control computer if the estimated vertical separation distance is below a threshold value such as, for example, 1,000 feet .

Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims .

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, wherein like reference characters denote similar elements throughout the several views:

FIG. 1 illustrates schematically a preferred embodiment of the present invention;

FIG. 2 depicts schematically a flowchart for implementing an embodiment of the early-warning collision avoidance system of the present invention; and

FIG. 3 is a block diagram of an aircraft altimetry monitoring system in accordance with the present invention. DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

Referring now to FIG. 1, there is shown a first aircraft 10 equipped with a satellite-based position-determining device such as, for example, a Global Positioning System (GPS) receiver

12, and a second aircraft 14 also equipped with a satellite-based position-determining device such as, for example, another Global

Positioning System receiver 12. Each of the first aircraft 10 and second aircraft 14 further includes a transmitter-receiver 16 for transmitting to and receiving from each other signals representing the position and/or trajectory of each aircraft, an altitude sensor 18 (e.g. a barometric type sensor) for measuring the pressure altitude of the host aircraft, and an airspeed sensor 20 (e.g. an aneroid pressure transducer) for measuring the airspeed of the host aircraft. Pressure altitude, as used herein, refers to the height above sea level as measured by a pressure altimeter such as, for example, altitude sensor 18.

The GPS receiver 12 provides its host aircraft information relating to the location of the host aircraft based on range signals from satellites of the Global Positioning System. The GPS has a network of 24 satellites distributed among six orbits (four satellites in each orbit) but the number of satellites "visible" to a GPS receiver 12 at any location varies with the time of the day. The GPS receiver 12 determines its position at time tj by obtaining the location of each of the visible GPS satellites and by measuring the range of those satellites on the basis of the propagation time of the range signals from each of those satellites. Signals from at least four GPS satellites are needed to determine a three-dimensional position (e.g., longitude, latitude and altitude) of the aircraft 10. The position of the GPS receiver is typically expressed in a global coordinate system or the so-called Earth-Centered Earth- Fixed (ECEF) coordinate system wherein the coordinate system origin is at the center of the Earth.

The accuracy of the position estimates of the GPS receiver 12 is affected by a multitude of errors including errors in the satellite position, propagation-induced signal delays, errors from multipath signals, noise in the GPS receiver 12, and intentionally induced errors in the signals by the Department of Defense which maintains the GPS. The geopotential height or the altitude component of the position estimate suffers from the additional problem that its accuracy or resolution is limited by the geometric spatial relationships of the satellites with respect to the GPS receiver. The absolute or geopotential height, as defined herein, is the distance between the center of the Earth and the location of the GPS receiver. A dimensionless metric or parameter, known to an ordinary artisan as the position dilution of precision (PDOP) , is often used to indicate the accuracy of the geopotential height estimate such that the smaller the PDOP value, the more accurate is the geopotential height estimate. Preferably, the PDOP value is less than 6.0. Typically, the geopotential height estimate computed by a stand-alone GPS receiver has an error in the range of about 100 to 200 feet, which is unacceptable for an aircraft flying through an RVSM airspace.

These errors, however, are substantially eliminated by computing the relative or differential geometric height between two GPS receivers because the aforementioned errors present in the absolute or geopotential height estimates are substantially cancelled in the process of forming their difference, provided the geopotential height estimates are obtained at an instant in time substantially the same or common as time tj . In such a case, the accuracy of the differential geometric height is quite high, as it has an error of less than about 10 feet. Advantageously, the present invention provides a collision avoidance system which analyzes the vertical separation distance between two adjacent aircraft to determine the likelihood of collision between the aircraft. The vertical separation distance between two adjacent aircraft is preferably determined by computing the difference between the absolute geometric heights measured -- at substantially the same or common instant of time - - by their respective GPS receivers.

Since the accuracy of the computed vertical separation depends greatly on the relative positions or geometric spatial relationship of the satellites with respect to the GPS receiver 12 at the time of measurement, it is preferable that additional information, such as, for example, the pressure altitude of the aircraft be also transmitted to the adjacent aircraft for comparison. A Kalman filter algorithm may, for example, be employed to determine the most likely vertical separation distance between the first and second aircraft 10 and 14 by assigning appropriate weights to the pressure altitude and geopotential height measurements of the first and second aircraft 10 and 14. The accuracy of the vertical separation estimate can still be further improved by pre-calibrating the barometric altitude sensor 18 of the aircraft during flight prior to the aircraft entering the RVSM airspace. This can be done by predisposing base stations 22 with stored reference pressure- height measurements (i.e. pressure measurements and corresponding geometric height measurements above the base station 22) and communication equipment for transmitting these measurements to the aircraft along the flight path of the aircraft as shown in Fig. 1. Each base station 22 preferably includes a GPS receiver 12 so that the geometric height of the aircraft relative to the base station 22 can be computed by determining the difference between the absolute geometric or geopotential heights of the base station 22 and the aircraft as explained above. The thus-derived geometric height of the aircraft with respect to base station 22 and the measured atmospheric pressure outside the aircraft can then be correlated with the reference pressure-height measurements of the base station 22, thereby enabling the aircraft altimetry system to adjust its computed pressure altitude accordingly. FIG. 2 schematically illustrates the inventive steps of a preferred embodiment of the present invention executed preferably concurrently by aircraft 10 and 14 of FIG. 1. Beginning at step 104, the aircraft altitude sensor 18, airspeed sensor 20, and GPS receiver 12 measure the barometric altitude (through static pressure) , airspeed (through impact pressure) and GPS data (e.g. coordinate position of the GPS receiver 12) of the aircraft respectively. The measurements are time stamped at step 106 and stored in, for example, the aircraft on-board digital air data computer (DADC) 30 (as shown in FIG.3) . At step 108, the DADC 30 computes pressure altitude, absolute geometric height using the latest or last received GPS data and airspeed (or ground speed) of the aircraft . Preferably, the computed values together with the time-stamp are then stored or recorded in, for example, the DADC 30. The DADC 30 thereafter pauses, at step 110, for a random or pseudo-random time period (as determined by, for example, a pseudo random number generator) prior to their transmission to another similarly equipped aircraft. This pause reduces the possibility that two similarly equipped aircraft operating in the same airspace will communicate at the same time or otherwise interfere with each other. The DADC 30 may, by way of example, pause every 1/100 of a second, every 1/50 of a second, or every second, etc uniformly on non-uniformly . At step 112, the DADC 30 transmits a low power signal that includes, for example, pressure altitude, GPS data such as absolute geometric or geopotential height, airspeed (and/or ground speed) , course coordinates, a time stamp indicating the time at which the transmitted data were measured, and data uniquely identifying the transmitting aircraft. In a particularly preferred embodiment, the aircraft 10 or 14 transmits using a low power transmitter at a frequency between approximately 108 MHz and approximately 133 MHz that is not normally used in the RVSM airspace. The DADC 30 may also be provided with the ability to "channel-hop, " i.e. to automatically switch transmitting channels (i.e. frequencies) if interference is detected on a particular channel or if the previously-selected channel is currently in use. The DADC 30 can also transmit sequentially at a plurality of frequencies as the aircraft approaches a boundary at which a particular frequency ceases to be unused.

With continued reference to FIG. 2, the DADC 30 preferably, at step 114, checks to see if signals representing GPS data, pressure altitude, geometric height, airspeed (and/or ground speed), course coordinates, a time stamp indicating the time at which the transmitted data was measured, have been received from another adjacent aircraft flying in the same RVSM airspace. If no data have been received, then the aircraft GPS receiver 12 records another, subsequent-in-time measurement beginning at step 104. When the aircraft 10 receives data from another aircraft at step 114, the DADC 30 compares the received data at step 116 with its measured and stored data including, for example, GPS derived geopotential height data, pressure altitude, that were measured at substantially the same instant of time as those of the other aircraft, as indicated by the time-stamp accompanying the transmission, and using, for example, a least squares fit method or a Kalman filter algorithm to determine whether an RVSM violation has occurred (or about to occur based on the projected trajectory of the approaching aircraft) at step 118, i.e. whether the vertical separation distance between the two adjacent aircraft is less than a threshold value such as, for example, 1,000 feet. If there is no RVSM violation, as determined at step 118, then the system loops back to step 104 and the GPS receiver 16 records another measurement. If the DADC 30 determines there is a RVSM violation at step 118, the pilot and/or a flight control computer is warned or alerted at step 120 to take corrective actions at step 122, including contacting the approaching aircraft. These steps are repeated as shown in Fig. 2 and data are updated and transmitted at the next randomly selected time period.

Thus, in accordance with the present invention, aircraft operating in RVSM airspace can continuously monitor the airspace for approaching aircraft and alert the pilots (and/or automated aircraft flight control and signalling systems) of RVSM violations by the approaching aircraft. Corrective action can thereby be initiated well in advance of any real danger, and travelling through an RVSM airspace is rendered safer and more automated as the present invention enables the DADC 30 to assume the task of dynamically monitoring and reporting a RVSM violation by, for example, warning or alerting the crew or automated flight computer of the approaching aircraft.

Referring now to FIG. 3, a DADC 30, pilot airspeed indicator/altimeter 60 and copilot airspeed indicator/altimeter 70 are separately connected to pairs of pressure inputs: 42 and 44, 62 and 64, and 72 and 74, respectively. Static source error data is collected using known methods and apparatus for each device and communicated via lines 46, 66, 76 to and stored in an EEPROM 52, which, in a preferred embodiment, is located in a connector 50. These data comprise static source error (SSE) data for a specific aircraft and provide a more accurate representation of the condition of the pressure input ports than normally provided by the manufacturer-preset SSE data. The SSE data can be used to automatically adjust or calibrate the raw measurement data so as to render more accurate computation of the pressure altitude, airspeed or other air data for a specific aircraft. The connector 50 is removably affixed to the DADC 30 and communicates SSE data over line 54. As the aircraft ages, new SSE data can be measured and stored in the EEPROM 52 (during flight or on the ground) to reflect the actual condition of the static pressure ports. The present invention thereby more accurately measures and monitors the condition of the static pressure ports which, in turn, provides a more accurate altimetry system. Although most preferably employed for RVSM operation, this feature of the present invention is equally useful for aircraft flying in traditional airspace.

Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.

Claims

CLAIMSI claim:
1. An aircraft collision avoidance method, comprising the steps of: determining geopotential heights of a first and a second aircraft at substantially a common instant of time using a satellite-based position determining device disposed on each of the first and the second aircraft; pausing for a first time period then transmitting data representing the geopotential height of the first aircraft from the first aircraft; pausing for a second time period then transmitting data representing the geopotential height of the second aircraft from the second aircraft; receiving the data from one of the first and the second aircraft by another one of the first and the second aircraft ; estimating a vertical separation distance between the first and the second aircraft at said substantially common instant of time using the received data by forming a difference between the geopotential heights of the first and the second aircraft; and reporting a warning if the estimated vertical separation distance is below a threshold value.
2. The method of claim 1, including randomly selecting the first and the second time periods.
3. The method of claim 1, further comprising the steps of determining pressure altitudes of the first and the second aircraft, transmitting data representing the pressure altitudes together with the data representing geopotential heights of corresponding said first and the second aircraft, and estimating the vertical separation distance between the first and the second aircraft based on the pressure altitudes and the geopotential heights of the first and the second aircraft using a Kalman filter algorithm.
4. The method of claim 3, further comprising the step of storing the data representing the geopotential heights and the data representing the pressure altitudes of the first and the second aircraft at the respective aircraft.
5. The method of claim 1, wherein the threshold value is about 1,000 feet.
PCT/US1998/006177 1997-03-27 1998-03-27 Satellite-based collision avoidance system and method therefor WO1998043107A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US4242297 true 1997-03-27 1997-03-27
US60/042,422 1997-03-27

Publications (1)

Publication Number Publication Date
WO1998043107A1 true true WO1998043107A1 (en) 1998-10-01

Family

ID=21921851

Family Applications (2)

Application Number Title Priority Date Filing Date
PCT/US1998/006297 WO1998043045A1 (en) 1997-03-27 1998-03-27 Method for calibrating aircraft altitude sensors
PCT/US1998/006177 WO1998043107A1 (en) 1997-03-27 1998-03-27 Satellite-based collision avoidance system and method therefor

Family Applications Before (1)

Application Number Title Priority Date Filing Date
PCT/US1998/006297 WO1998043045A1 (en) 1997-03-27 1998-03-27 Method for calibrating aircraft altitude sensors

Country Status (5)

Country Link
US (1) US5940035A (en)
JP (1) JP3682980B2 (en)
DE (1) DE69818813D1 (en)
EP (1) EP0974039B1 (en)
WO (2) WO1998043045A1 (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7667647B2 (en) 1999-03-05 2010-02-23 Era Systems Corporation Extension of aircraft tracking and positive identification from movement areas into non-movement areas
US7739167B2 (en) 1999-03-05 2010-06-15 Era Systems Corporation Automated management of airport revenues
US7777675B2 (en) 1999-03-05 2010-08-17 Era Systems Corporation Deployable passive broadband aircraft tracking
US7782256B2 (en) 1999-03-05 2010-08-24 Era Systems Corporation Enhanced passive coherent location techniques to track and identify UAVs, UCAVs, MAVs, and other objects
US7889133B2 (en) 1999-03-05 2011-02-15 Itt Manufacturing Enterprises, Inc. Multilateration enhancements for noise and operations management
US7908077B2 (en) 2003-06-10 2011-03-15 Itt Manufacturing Enterprises, Inc. Land use compatibility planning software
US7965227B2 (en) 2006-05-08 2011-06-21 Era Systems, Inc. Aircraft tracking using low cost tagging as a discriminator
US8072382B2 (en) 1999-03-05 2011-12-06 Sra International, Inc. Method and apparatus for ADS-B validation, active and passive multilateration, and elliptical surveillance
US8203486B1 (en) 1999-03-05 2012-06-19 Omnipol A.S. Transmitter independent techniques to extend the performance of passive coherent location
US8446321B2 (en) 1999-03-05 2013-05-21 Omnipol A.S. Deployable intelligence and tracking system for homeland security and search and rescue

Families Citing this family (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7132982B2 (en) * 1999-03-05 2006-11-07 Rannock Corporation Method and apparatus for accurate aircraft and vehicle tracking
GB9907123D0 (en) * 1999-03-26 1999-05-19 Bide Stephen Position finding
GB9930245D0 (en) * 1999-12-21 2000-02-09 Nokia Mobile Phones Ltd Communication handset
US6518918B1 (en) * 2000-05-11 2003-02-11 Lucent Technologies Inc. Wireless assisted altitude measurement
US6525687B2 (en) 2001-02-12 2003-02-25 Enuvis, Inc. Location-determination method and apparatus
US6522298B1 (en) * 2001-04-12 2003-02-18 Garmin Ltd. Device and method for calibrating and improving the accuracy of barometric altimeters with GPS-derived altitudes
US6735542B1 (en) 2001-05-09 2004-05-11 Garmin Ltd. Method and apparatus for calculating altitude based on barometric and GPS measurements
GB0311138D0 (en) * 2003-05-15 2003-06-18 Univ Wales Bangor Improvements in or relating to diagnostics
US6927725B2 (en) * 2003-12-12 2005-08-09 The Boeing Company System and method for radar detection and calibration
US20060259216A1 (en) * 2004-09-30 2006-11-16 Honeywell International, Inc. System and method for calibrating on-board aviation equipment
US7391320B1 (en) 2005-04-01 2008-06-24 Horizon Hobby, Inc. Method and system for controlling radio controlled devices
WO2007053262A3 (en) * 2005-10-07 2009-04-23 Louis C Delemarre Object locating arrangements, and in particular, aircraft geometric height measurement arrangements
US7400293B2 (en) * 2006-01-12 2008-07-15 Global Aerospace, Llc Atmospheric turbulence analysis system
US20070162197A1 (en) * 2006-01-12 2007-07-12 Global Aerospace, Llc Airplane system for an atmospheric turbulence analysis system
US8331888B2 (en) * 2006-05-31 2012-12-11 The Boeing Company Remote programmable reference
US8666569B2 (en) * 2007-02-16 2014-03-04 Honeywell International Inc. Methods and systems for health monitoring for aircraft
US9057606B2 (en) * 2009-09-10 2015-06-16 Nextnav, Llc Wide area positioning system
JP4892695B2 (en) * 2009-01-16 2012-03-07 防衛省技術研究本部長 Instrument calibration flight test methods take advantage of the kinematic gps
CN101572017B (en) 2009-06-01 2011-03-30 民航数据通信有限责任公司;北京航空航天大学 Method for extracting cruise section of flight path from air craft three dimensional position sequence
CN101706283B (en) 2009-11-18 2011-10-19 南京航空航天大学 Method for transonic shock wave interference adaptive suppression of altitude channel
KR101232053B1 (en) 2010-12-23 2013-02-15 국방과학연구소 Barometric altimeter and self-setting method of the same based on onboard navigation data in flight
EP2667280A1 (en) * 2012-05-23 2013-11-27 Nxp B.V. Device Control System And Method Of Determining Altitude
US9766065B2 (en) * 2013-03-15 2017-09-19 Exelis Inc. Reduction of altitude error using forecasted atmospheric pressure data
US20160238387A1 (en) * 2015-02-17 2016-08-18 Kushal Singh Object descent detection system and method thereof
CN105509709B (en) * 2015-11-27 2017-10-13 上海斐讯数据通信技术有限公司 A portable height measurement system, method and a mobile terminal
WO2017174238A1 (en) * 2016-04-05 2017-10-12 Deutsches Zentrum für Luft- und Raumfahrt e.V. Method and device for detecting a fault of a barometric pressure measuring system arranged aboard a flying device

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4835537A (en) * 1986-07-16 1989-05-30 Manion James H Telemetry burst collision avoidance system
US5153836A (en) * 1990-08-22 1992-10-06 Edward J. Fraughton Universal dynamic navigation, surveillance, emergency location, and collision avoidance system and method
US5325302A (en) * 1990-10-15 1994-06-28 Bvr Technologies, Ltd. GPS-based anti-collision warning system
US5450329A (en) * 1993-12-22 1995-09-12 Tanner; Jesse H. Vehicle location method and system
US5506587A (en) * 1991-07-01 1996-04-09 Gp & C Systems International Ab Position indicating system
US5570095A (en) * 1994-04-01 1996-10-29 Massachusetts Institute Of Technology Automatic dependent surveillance air navigation system
US5596332A (en) * 1994-04-19 1997-01-21 Northrop Corporation Aircraft location and identification system
US5636123A (en) * 1994-07-15 1997-06-03 Rich; Richard S. Traffic alert and collision avoidance coding system

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4292671A (en) * 1979-07-30 1981-09-29 Hydac, Inc. Digital altimeter computer
US4431994A (en) * 1981-05-06 1984-02-14 The United States Of America As Represented By The Secretary Of The Air Force Combined radar/barometric altimeter
DE3677018D1 (en) * 1986-11-12 1991-02-21 Litef Gmbh Method for determining the altitude of a fluggeraets.
US5260874A (en) * 1990-09-05 1993-11-09 The Boeing Company Aircraft flight emulation test system
US5272639A (en) * 1992-01-14 1993-12-21 Honeywell Inc. Terrain referenced navigation electromagnetic-gravitational correlation
US5402116A (en) * 1992-04-28 1995-03-28 Hazeltine Corp. Atmospheric pressure calibration systems and methods
US5646857A (en) * 1995-03-31 1997-07-08 Trimble Navigation Limited Use of an altitude sensor to augment availability of GPS location fixes
US5627546A (en) * 1995-09-05 1997-05-06 Crow; Robert P. Combined ground and satellite system for global aircraft surveillance guidance and navigation

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4835537A (en) * 1986-07-16 1989-05-30 Manion James H Telemetry burst collision avoidance system
US5153836A (en) * 1990-08-22 1992-10-06 Edward J. Fraughton Universal dynamic navigation, surveillance, emergency location, and collision avoidance system and method
US5325302A (en) * 1990-10-15 1994-06-28 Bvr Technologies, Ltd. GPS-based anti-collision warning system
US5506587A (en) * 1991-07-01 1996-04-09 Gp & C Systems International Ab Position indicating system
US5450329A (en) * 1993-12-22 1995-09-12 Tanner; Jesse H. Vehicle location method and system
US5570095A (en) * 1994-04-01 1996-10-29 Massachusetts Institute Of Technology Automatic dependent surveillance air navigation system
US5596332A (en) * 1994-04-19 1997-01-21 Northrop Corporation Aircraft location and identification system
US5636123A (en) * 1994-07-15 1997-06-03 Rich; Richard S. Traffic alert and collision avoidance coding system

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7667647B2 (en) 1999-03-05 2010-02-23 Era Systems Corporation Extension of aircraft tracking and positive identification from movement areas into non-movement areas
US7739167B2 (en) 1999-03-05 2010-06-15 Era Systems Corporation Automated management of airport revenues
US7777675B2 (en) 1999-03-05 2010-08-17 Era Systems Corporation Deployable passive broadband aircraft tracking
US7782256B2 (en) 1999-03-05 2010-08-24 Era Systems Corporation Enhanced passive coherent location techniques to track and identify UAVs, UCAVs, MAVs, and other objects
US7889133B2 (en) 1999-03-05 2011-02-15 Itt Manufacturing Enterprises, Inc. Multilateration enhancements for noise and operations management
US8072382B2 (en) 1999-03-05 2011-12-06 Sra International, Inc. Method and apparatus for ADS-B validation, active and passive multilateration, and elliptical surveillance
US8203486B1 (en) 1999-03-05 2012-06-19 Omnipol A.S. Transmitter independent techniques to extend the performance of passive coherent location
US8446321B2 (en) 1999-03-05 2013-05-21 Omnipol A.S. Deployable intelligence and tracking system for homeland security and search and rescue
US7908077B2 (en) 2003-06-10 2011-03-15 Itt Manufacturing Enterprises, Inc. Land use compatibility planning software
US7965227B2 (en) 2006-05-08 2011-06-21 Era Systems, Inc. Aircraft tracking using low cost tagging as a discriminator

Also Published As

Publication number Publication date Type
EP0974039A4 (en) 2000-06-14 application
EP0974039A1 (en) 2000-01-26 application
EP0974039B1 (en) 2003-10-08 grant
JP2001522456A (en) 2001-11-13 application
WO1998043045A1 (en) 1998-10-01 application
JP3682980B2 (en) 2005-08-17 grant
US5940035A (en) 1999-08-17 grant
DE69818813D1 (en) 2003-11-13 grant

Similar Documents

Publication Publication Date Title
US6690296B2 (en) Airborne alerting system
US5504492A (en) Look ahead satellite positioning system position error bound monitoring system
US6064335A (en) GPS based augmented reality collision avoidance system
US5406286A (en) Real time passive threat positioning system
US6469654B1 (en) Transponder landing system
US6218961B1 (en) Method and system for proximity detection and location determination
US6512976B1 (en) Method and system for terrain aided navigation
US6424290B1 (en) Narrowband passive differential tracking system (U)
US6469660B1 (en) Method and system for displaying target icons correlated to target data integrity
US5867122A (en) Application of GPS to a railroad navigation system using two satellites and a stored database
US4161734A (en) Position surveillance using one active ranging satellite and time of arrival of a signal from an independent satellite
US5760737A (en) Navigation system with solution separation apparatus for detecting accuracy failures
US6427122B1 (en) Positioning and data integrating method and system thereof
US20050110676A1 (en) Method and apparatus for satellite-based relative positioning of moving platforms
US4161730A (en) Radio determination using satellites transmitting timing signals with correction by active range measurement
US4866450A (en) Advanced instrument landing system
US5883595A (en) Method and apparatus for mitigating multipath effects and smoothing groundtracks in a GPS receiver
US4894655A (en) Landing assistance system using navigation satellites
US5557284A (en) Spoofing detection system for a satellite positioning system
US20040239560A1 (en) Hybrid inertial navigation system with improved integrity
US5596328A (en) Fail-safe/fail-operational differential GPS ground station system
US20070001903A1 (en) Use of geo-stationary satellites to augment wide_area multilateration synchronization
US5610616A (en) Differential GPS ground station system
US5969670A (en) Inexpensive monitoring technique for achieving high level integrity monitoring for differential GPS
US5923286A (en) GPS/IRS global position determination method and apparatus with integrity loss provisions

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP KR

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AM AZ BY KG KZ MD RU TJ TM AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase in:

Ref country code: JP

Ref document number: 1998546036

Format of ref document f/p: F

122 Ep: pct application non-entry in european phase