Publications

Refine Results

(Filters Applied) Clear All

GPS-squitter automatic dependent surveillance broadcast: flight testing in the Gulf of Mexico

Summary

During November - December 1994, MIT Lincoln Laboratory conducted a field evaluation of the air surveillance capabilities of GPS-Squitter in the Gulf of Mexico. Three squitter ground stations were located in the vincinity of Morgan City, Louisiana, for this evaluation: two were located on offshore oil platforms, and the third was located at an onshore heliport. Surveillance coverage tests were flown over the Gulf with three test aircraft - two helicopters and one Cessna 421 fixed wing aircraft. The helicopters flew at altitudes ranging from 100 to 2000 feet above sea level and the Cessna flew at 7500 and 20,000 feet. Extended squitter messages broadcast by each of the test aircraft provided aircraft position and identification. This report documents results of these texts and compares measured coverage to predicted coverage from the ground stations. Based on the good agreement between predicted and measured performance, a description of a possible operational system is included that would provide surveillance of the entire Gulf region serviced by oil platform helicopters. The report concludes that GPS Squitter is a near-term option for providing accurate, real time surveillance of aircraft operating in the offshore airspace in the Gulf of Mexico.
READ LESS

Summary

During November - December 1994, MIT Lincoln Laboratory conducted a field evaluation of the air surveillance capabilities of GPS-Squitter in the Gulf of Mexico. Three squitter ground stations were located in the vincinity of Morgan City, Louisiana, for this evaluation: two were located on offshore oil platforms, and the third...

READ MORE

Automatic dependent surveillance broadcast via GPS-squitter: a major upgrade to the National Airspace System

Published in:
SPIE, Vol. 2464, Air Traffic Control Technologies, 18-19 April 1995, pp. 2-13.

Summary

GPS-Squitter is a technology for Surveillance of aircraft via broadcast of their GPS-determined positions to all listeners, using the Mode S data link. It can be used to provide traffic displays, on the ground for controllers and in the cockpit for pilots, and will enhance TCAS performance. It is compatible with the existing ground-based beacon interrogator radar system and is an evolutionary way to move from ground-based-radar surveillance to satellite-based surveillance. GPS-Squitter takes advantage of the substantial investment made by the U.S. in the powerful GPS position-determining system and has the potential to free the Federal Aviation Administration from having to continue maintaining a precise position-determining capability in ground-based radar. This would permit phasing out the ground-based secondary surveillance radar system over a period of 10 to 20 years and replacing it with much simpler ground stations, resulting in cost savings of hundreds of millions of dollars.
READ LESS

Summary

GPS-Squitter is a technology for Surveillance of aircraft via broadcast of their GPS-determined positions to all listeners, using the Mode S data link. It can be used to provide traffic displays, on the ground for controllers and in the cockpit for pilots, and will enhance TCAS performance. It is compatible...

READ MORE

Airport surface surveillance using differential GPS and the Mode S data link

Published in:
Proc. 50th Annual Mtg. of the Institute of Navigation, 6-8 June 1994, pp. 335-344.

Summary

A new concept for providing surface surveillance of aircraft and ground vehicles has recently been tested at Hanscom Field in Bedford, Massachusetts. This concept, known as GPS-Squitter, combines the capabilities of differential GPS for navigation with those of the Mode S data link for communications. Together these systems provide accurate surveillance data along with a positive identification of surface traffic, both very important for an effective surface meillance system. The GPS-Squitter concept is based on the use of the Mode S squitter. The current squitter is a 56bit Mode S all-call reply message spontaneously broadcast by all aircraft Mode S transponders at a 1Hz rate. This message provides the unique Mode S address of an aircrsft and is used by TCAS (Traffic Alert and Collision Avoidance System) for acquisition of nearby aircraft. In the Hanscom testing, this squitter was extended to include GPS-based surveillance information. Two target vehicles participated in the experiments - one aircraft and one ground vehicle. They determined their position, heading, and speed using differential GPS and automatically broadcast that surveillance information to ground transmit/receive stations using the modified squitter. Differential GPS pseudorange and pseudorange rate corrections were formed by a reference station located at Hanscom Field and were transmitted by the ground transmit receive stations to the target vehicles. This paper describes the configuration of the target vehicles, the ground transmit/receive stations, and the differential GPS reference station. Results of the surface surveillance testing are provided including: system coverage, surveillance update rate, and differential GPS data quality. Ongoing testing at Logan International Airport is also discussed.
READ LESS

Summary

A new concept for providing surface surveillance of aircraft and ground vehicles has recently been tested at Hanscom Field in Bedford, Massachusetts. This concept, known as GPS-Squitter, combines the capabilities of differential GPS for navigation with those of the Mode S data link for communications. Together these systems provide accurate...

READ MORE

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

Published in:
Navig. J. Inst. Navig., Vol. 41, No. 2, Summer 1994, pp. 187-206.

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.
READ LESS

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...

READ MORE

ADS-Mode S

Published in:
Proc. 38th Annual Air Traffic Control Association Convention, 24-28 October 1993, pp. 230-236.

Summary

The International Civil Aviation Organization (ICAO) has defined a concept for communications, navigation, and surveillance for the next century known as the Future Air Navigation System (FANS). A cornerstone, of the FANS is an increasing reliance on satellite-based position-determining systems such as the Global Positioning System (GPS). In the case of, surveillance, aircraft position information is automatically downlinked to ground controllers. This technique is known as Automatic Dependent Surveillance (ADS). ADS-Mode S is an ADS system concept utilizing the frequencies and formats of the Mode S system for downlinking position information and also uplinking differential GPS (DGPS) corrections. The result is an integrated concept for surveillance that permits aircraft equipped with a Mode S transponder and a GPS receiver to participate in both ADS and beacon ground environments. This makes possible a smooth transition of the National Airspace System (NAS) secondary surveillance system from a beacon-based to an ADS-based environment. In addition, several other benefits from ADS-Mode S accrue to the Traffic Alert and Collision Avoidance System (TCAS) and to the Mode S Data Link system.
READ LESS

Summary

The International Civil Aviation Organization (ICAO) has defined a concept for communications, navigation, and surveillance for the next century known as the Future Air Navigation System (FANS). A cornerstone, of the FANS is an increasing reliance on satellite-based position-determining systems such as the Global Positioning System (GPS). In the case...

READ MORE

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

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.

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...

READ MORE

Showing Results

1-6 of 6