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Demonstration of GPS Automatic Dependent Surveillance of aircraft using spontaneous Mode S broadcast messages

June 1, 1994
  |
Journal Article
Author:
Edward T. Bayliss
…
Published in:
Navig. J. Inst. Navig., Vol. 41, No. 2, Summer 1994, pp. 187-206.
Topic:
surveillance
R&D area:
R&D group:

Summary

A new Automatic Dependent Surveillance (ADS) system concept combining GPS-based positions with Mode S data communications is described. Several potential applications of this concept are presented with emphasis on surface surveillance at airports. The navigation and data link performance are analyzed. Compact ADS position formats are included. The results of the first tests at Hanscom Field, demonstrating the feasibility of the spontaneous broadcast of ADS positions using Mode S messages are presented. Test aircraft, vehicles, avionics equipment and the ground system configuration are described. Avionics standards and GPS interface requirements are discussed. Multipath and airport surface coverage issues are addressed. Further testing in an operational environment is continuing at Logan Airport.
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Summary

A new Automatic Dependent Surveillance (ADS) system concept combining GPS-based positions with Mode S data communications is described. Several potential applications of this concept are presented with emphasis on surface surveillance at airports. The navigation and data link performance are analyzed. Compact ADS position formats are included. The results of...

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Demonstration of GPS Automatic Dependent Surveillance of aircraft using spontaneous Mode S broadcast messages

Aircraft surveillance based on GPS position broadcasts from mode S beacon transponders

January 1, 1994
  |
Conference Paper
Author:
Edward T. Bayliss
…
Published in:
Proc. of ION GPS, v 1, 1994, pp. 939-950.
Topic:
surveillance
R&D area:
R&D group:

Summary

Flight testing of a new air surveillance concept, GPS-Squitter, is reported. It integrates GPS receivers with the existing secondary surveillance radar beacon equipment carried by most aircraft. Simple, inexpensive, non-scanning ground stations listen for GPS position reports broadcast by the Mode S beacon transponders on the aircraft and send them on to air traffic control facilities. In addition to its surveillance application, GPS-Squitter presents opportunities for enhancing other important functions such as collision avoidance systems and data link services. System tradeoff studies are comparing range and altitude coverage with the cost and number of stations needed. Other issues are data link interference, multipath, total aircraft capacity, and unambiguous reporting range. The baseline system uses commercial off-the-shelf components such as TCAS (Traffic Alerting and Collision Avoidance System) avionics units, omni-directional DME (Distance Measuring Equipment) antennas, and computer workstations in order to ensure low production costs. The cost/performance tradeoff of minimum modifications such as the addition of a 6-sector antenna, multiple receive channels, or higher transmit power, are being evaluated. The omni-directional baseline system is designed for a range of 50 nmi while the 6-sector system is designed for 100 nmi range. Two aircraft have been equipped with Mode S beacon transponders modified to broadcast (i.e., "squitter") their GPS position twice each second. The numerous test flights have accumulated a significant data base including a demonstration of coverage out to over 100 nmi range. Data have been collected to analyze a number of issues: received power margins, performance of bottom versus top aircraft antenna, ground bounce multipath, propagation over water, and parallel runway approach monitoring. In addition, standard squitter data from commercial aircraft have been recorded and correlated with Mode S tracking to show link margins experienced in practice from aircraft in operational service. More tests are planned, including a demonstration of GPS-Squitter air surveillance in the Gulf of Mexico.
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Summary

Flight testing of a new air surveillance concept, GPS-Squitter, is reported. It integrates GPS receivers with the existing secondary surveillance radar beacon equipment carried by most aircraft. Simple, inexpensive, non-scanning ground stations listen for GPS position reports broadcast by the Mode S beacon transponders on the aircraft and send them...

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Aircraft surveillance based on GPS position broadcasts from mode S beacon transponders

Demonstration of GPS automatic dependent surveillance of aircraft using spontaneous Mode S beacon reports

September 22, 1993
  |
Conference Paper
Author:
Edward T. Bayliss
…
Published in:
Proc. ION-GPS-93 Sixth Int. Technical Mtg. of the Satellite Division of the Institute of Navigation, 22-24 September 1993, pp. 1-13.
Topic:
surveillance
R&D area:
R&D group:

Summary

A new Automatic Dependent Surveillance (ADS) system concept combining GPS satellite navigation with Mode S data communications is described. Several potential applications of this concept are presented with emphasis on surface surveillance at airports. The navigation and data link performance are analyzed. Compact ADS position formats are included. The results of the first tests at Hanscom Field demonstrating the feasibility of the spontaneous broadcast of ADS positions using Mode S messages are presented. Test aircraft, vehicles, avionics equipment and the ground system configuration are described. Avionics standards and GPS interface requirements are discussed. Multipath and airport surface coverage issues are addressed. Plans for further testing in an operational environment at Logan Airport are outlined.
READ LESS

Summary

A new Automatic Dependent Surveillance (ADS) system concept combining GPS satellite navigation with Mode S data communications is described. Several potential applications of this concept are presented with emphasis on surface surveillance at airports. The navigation and data link performance are analyzed. Compact ADS position formats are included. The results...

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Demonstration of GPS automatic dependent surveillance of aircraft using spontaneous Mode S beacon reports

SGS85--WGS84 transformation - interim results

August 24, 1993
  |
Project Report
Author:
Pratap N. Misra
…
Published in:
MIT Lincoln Laboratory Report ATC-204
Topic:
GPS
R&D area:

Summary

GPS and GLONASS employ different geocentric Cartesian coordinate frames to express the positions of their satellites and, therefore, of their users. GPS uses WGS84; GLONASS, SGS85. Interest in the civil aviation community in using signals from both systems requires that a transformation between the two coordinate frames be determined. We present an estimate of the SGS85--WGS84 transformation.
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Summary

GPS and GLONASS employ different geocentric Cartesian coordinate frames to express the positions of their satellites and, therefore, of their users. GPS uses WGS84; GLONASS, SGS85. Interest in the civil aviation community in using signals from both systems requires that a transformation between the two coordinate frames be determined. We...

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SGS85--WGS84 transformation - interim results

GLONASS performance in 1992: a review

May 1, 1993
  |
Journal Article
Author:
Pratap N. Misra
…
Published in:
GPS World, Vol. 4, No. 5, May 1993, pp. 28-39.
Topic:
satellites
R&D area:
R&D group:

Summary

Researchers at MIT's Lincoln Laboratory reviewed GLONASS developments during 1992, focusing on the requirements of civil aviation and the issues related to position estimation. The results show that the overall performance remains substantially the same as observed in 1991.
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Summary

Researchers at MIT's Lincoln Laboratory reviewed GLONASS developments during 1992, focusing on the requirements of civil aviation and the issues related to position estimation. The results show that the overall performance remains substantially the same as observed in 1991.

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GLONASS performance in 1992: a review

Receiver Autonomous Integrity Monitoring (RAIM) of GPS and GLONASS

March 1, 1993
  |
Journal Article
Author:
Pratap N. Misra
…
Published in:
Navig. J. Inst. Navig., Vol. 40, No. 1, Spring 1993, pp. 87-104.
Topic:
autonomous systems
R&D area:
R&D group:

Summary

A receiver autonomous integrity monitoring (RAIM) algorithm is proposed, and used to analyze the integrity monitoring capabilities of potential sole-means (or stand-alone) systems based on integrated use of GPS and GLONASS, GPS supplemented with a geostationary overlay, and enhanced GPS constellations. As in the other RAIM algorithms, the idea is to take advantage of the redundant measurements. Our focus, however, is on the quality of the position estimate, rather than on diagnosing whether the system is working as intended. The proposed approach uses the redundant measurements to generate a position estimate and a measure of its quality. The latter, called integrity level, is defined as an upper bound on the position error. The estimation of the integrity level is the main innovation in the proposed scheme. The RAIM algorithm is tailored to an abundant redundancy of the measurements, and addresses the following issue: Given a snapshot of the pseudo range measurements, one of which may be in error, can we compute a position estimate that can be shown with high confidence to meet the user's accuracy requirement?
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Summary

A receiver autonomous integrity monitoring (RAIM) algorithm is proposed, and used to analyze the integrity monitoring capabilities of potential sole-means (or stand-alone) systems based on integrated use of GPS and GLONASS, GPS supplemented with a geostationary overlay, and enhanced GPS constellations. As in the other RAIM algorithms, the idea is...

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Receiver Autonomous Integrity Monitoring (RAIM) of GPS and GLONASS

Integrated use of GPS and GLONASS in civil aviation navigation I: coverage and data models

September 19, 1990
  |
Conference Paper
Author:
Pratap N. Misra
…
Published in:
Institute of Navigation, 3rd Int. Technical Mtg. of the Satellite Division, 19-21 September 1990, pp. 425-435.
Topic:
satellites
R&D area:
R&D group:

Summary

Pursuant to a bilateral agreement signed in 1988, both US and USSR are currently in the process of examining integrated use of GPS and GLONASS for sole-means civil aviation navigation. This paper presents results from the initial phase of a program underway at MIT Lincoln Laboratory to support this effort. Specifically, we present results on satellite coverage and quality of the range measurements from GPS and GLONASS. The coverage results highlight the extent to which each system alone falls short of providing a self-contained system integrity check. In integrated use, however, there are enough redundant measurements to make receiver autonomous integrity monitoring (RAIM) practical. The data quality results are based on statistical analysis of the range measurements from GPS, at various levels of selective availability (SA), collected over extended periods. We present empirical cumulative distribution function of the range error, and RMS value of its component, defined as the 'effective' range error, relevant to position estimation. These results are used to project the position estimation. These results are used to project the position estimation accuracy achievable globally with GPS, when operational. Comparable results for GLONASS are being developed. The coverage and data quality results together provide a basis for development of the navigation and RAIM algorithms for the integrated use. This will be addressed in the next phase of the program. The important considerations in the design of these algorithms, including the differences in the reference systems for space and time employed by the two systems, are briefly reviewed.
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Summary

Pursuant to a bilateral agreement signed in 1988, both US and USSR are currently in the process of examining integrated use of GPS and GLONASS for sole-means civil aviation navigation. This paper presents results from the initial phase of a program underway at MIT Lincoln Laboratory to support this effort...

READ MORE
Integrated use of GPS and GLONASS in civil aviation navigation I: coverage and data models
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