Publications

Refine Results

(Filters Applied) Clear All

Tagged As

ADS-Mode S system overview

October 25, 1993
  |
Conference Paper
Author:
Robert E. Boisvert
…
Published in:
AIAA/IEEE Digital Avionics Systems Conf., 25-28 October 1993, pp. 104-109.
Topic:
collision avoidance
R&D area:
R&D group:

Summary

ADS-Mode S is a system concept that merges the capabilities of Automatic Dependent Surveillance and the Mode S beacon radar. The result is an integrated system for seamless surveillance and data link that permits equipped aircraft to participate in ADS or beacon ground environments. This offers many possibilities for transitioning from a beacon to an ADS based surveillance system. The ADS-Mode S squitter. The current Mode S squitter is a spontaneous, periodic (once per second) 56-bit broadcast message containing the Mode S 24-bit address. This broadcast is provided by all Mode S transponders and is used by the Traffic Alert and Collision Avoidance System (TCAS) to acquire nearby Mode S equipped aircraft. For ADS-Mode S use, this squitter broadcast would be extended to 112 bits to provide for the transmission of a 56-bit ADS message field. The ADS squitter would be transmitted in addition to the current TCAS squitter in order to maintain compatibility with current TCAS equipment during transition.
READ LESS

Summary

ADS-Mode S is a system concept that merges the capabilities of Automatic Dependent Surveillance and the Mode S beacon radar. The result is an integrated system for seamless surveillance and data link that permits equipped aircraft to participate in ADS or beacon ground environments. This offers many possibilities for transitioning...

READ MORE
ADS-Mode S system overview

Air-to-air visual acquisition handbook

November 27, 1991
  |
Project Report
Author:
John W. Andrews
Published in:
MIT Lincoln Laboratory Report ATC-151
Topic:
collision avoidance
R&D area:
R&D group:

Summary

The document describes a set of computer programs that provide a practical means for predicting air-to-air visual acquisition performance for aircraft on collision courses. The programs are based upon a mathematical model of pilot visual acquisition performance. Guidelines are provided for selecting model parameters based upon previously collected flight test data. Selected results of computer analysis are provided.
READ LESS

Summary

The document describes a set of computer programs that provide a practical means for predicting air-to-air visual acquisition performance for aircraft on collision courses. The programs are based upon a mathematical model of pilot visual acquisition performance. Guidelines are provided for selecting model parameters based upon previously collected flight test...

READ MORE
Air-to-air visual acquisition handbook

Unalerted air-to-air visual acquisition

November 26, 1991
  |
Project Report
Author:
John W. Andrews
Published in:
MIT Lincoln Laboratory Report ATC-152
Topic:
collision avoidance
R&D area:
R&D group:

Summary

A series of flight tests were flown to measure pilot air-to-air visual acquisition performance for pilots employing unalerted visual search. Twenty-four general aviation subject pilots flew a cross-country route while an intercepting aircraft was controlled to produce three intercepts with altitude separation of 500 feet. Pilots received no traffic advisory information to alert them to the possible presence of the intercepting aircraft. Results were analyzed to estimate the instantaneous rate of visual acquisition for a visual target of specified size and contrast. The results were used to calibrate a mathematical model of visual acquisition that can be used to predict pilot performance under a range of conditions.
READ LESS

Summary

A series of flight tests were flown to measure pilot air-to-air visual acquisition performance for pilots employing unalerted visual search. Twenty-four general aviation subject pilots flew a cross-country route while an intercepting aircraft was controlled to produce three intercepts with altitude separation of 500 feet. Pilots received no traffic advisory...

READ MORE
Unalerted air-to-air visual acquisition

TCAS: a system for preventing midair collisions

January 1, 1989
  |
Journal Article
Author:
William H. Harman III
Published in:
Lincoln Laboratory Journal, Vol. 2, No. 3, Fall 1989, pp. 437-458.
Topic:
air traffic control
R&D area:
R&D group:

Summary

To reduce the possibility of midair collisions, the Federal Aviation Administration has developed the Traffic Alert and Collision Avoidance System, or TCAS. This airborne system senses the presence of nearby aircraft by interrogating the transponders carried by these aircraft. When TCAS senses that a nearby aircraft is a possible collision threat, TCAS issues a traffic advisory to the pilot, indicating the presence and location of the other aircraft. If the encounter becomes hazardous, TCAS issues a maneuver advisory.
READ LESS

Summary

To reduce the possibility of midair collisions, the Federal Aviation Administration has developed the Traffic Alert and Collision Avoidance System, or TCAS. This airborne system senses the presence of nearby aircraft by interrogating the transponders carried by these aircraft. When TCAS senses that a nearby aircraft is a possible collision...

READ MORE
TCAS: a system for preventing midair collisions

TCAS Experimental Unit (TEU) hardware description

June 6, 1986
  |
Project Report
Author:
Joseph DiBartolo Jr
…
Published in:
MIT Lincoln Laboratory Report ATC-133
Topic:
collision avoidance
R&D area:
R&D group:

Summary

This report describes the hardware design of the TCAS Experimental Units (TEU's) constructed by Lincoln Laboratory to support the design and validation of the Traffic Alert and Collision Avoidance System (TCAS) for the FAA. Section 1.0 presents an overview of the operation of hte TEU's, in order to give some context for the hardware design. References are given to more extensive descriptions of the TCAS system operation and software design. Section 2.0 constitutes the bulk of the report, and is a detailed description of the TEU hardware design. The purpose of this description is to document the design details of the equipment which was used to develop and validate the signal processing techniques and algorithms which appear in the TCAS II Minimum Operational Performance Standard, the TCAS National Standard and various technical reports listed in the references. A second purpose is to provide design guidance to potential TCAS II manufacturers, in the form of a detailed description of a feasible design with documented performance. Finally, this document is a manual for future use and maintenance of the TEU's.
READ LESS

Summary

This report describes the hardware design of the TCAS Experimental Units (TEU's) constructed by Lincoln Laboratory to support the design and validation of the Traffic Alert and Collision Avoidance System (TCAS) for the FAA. Section 1.0 presents an overview of the operation of hte TEU's, in order to give some...

READ MORE
TCAS Experimental Unit (TEU) hardware description

Pilot evaluation of TCAS in the Long Ranger helicopter

June 3, 1986
  |
Project Report
Author:
John W. Andrews
Published in:
MIT Lincoln Laboratory Report ATC-136
Topic:
collision avoidance
R&D area:
R&D group:

Summary

A specially modified version of the Traffic Alert and Collision Avoidance System (TCAS) was installed in a Bell Long Ranger helicopter in order to investigate the feasibility of TCAS operation in rotorcraft. This installation employed TCAS air-to-air surveillance to provide automated traffic advisories that were displayed in the cockpit on a color cathod ray tube display. As part of this study, 12 subject pilots evaluated the utility of the installation thorugh brief test flights in the vicinity of a major airport. Among the topics investigated were the rate of alarms, the computer logic for issuing advisories, the bearing accuracy, and the display symbology. Several recommendations for adapting TCAS to the rotorcraft environment resulted from the testing.
READ LESS

Summary

A specially modified version of the Traffic Alert and Collision Avoidance System (TCAS) was installed in a Bell Long Ranger helicopter in order to investigate the feasibility of TCAS operation in rotorcraft. This installation employed TCAS air-to-air surveillance to provide automated traffic advisories that were displayed in the cockpit on...

READ MORE
Pilot evaluation of TCAS in the Long Ranger helicopter

Effect of interference on the performance of a minimum TCAS II

September 5, 1985
  |
Project Report
Author:
Ronald G. Sandholm
Published in:
MIT Lincoln Laboratory Report ATC-132
Topic:
collision avoidance
R&D area:
R&D group:

Summary

Minimum TCAS II equipment is required to operate reliably in all aircraft densities up to the 0.3 transponder-equipped aircraft per square nautical mile anticipated in the Los Angeles Basin in the year 2000. Prototype TCAS equipment has been developed and shown to be capable of providing reliable surveillance in today's highest densities, which reach an average of about 0.1 aircraft per square nmi. Since there are no existing environments that reach the density of asynchronous interference anticipated for the Los Angeles Basin in the year 2000, it is necessary to generate simulated interference to determine the performance of the TCAS II design in that environment. A series of bench tests were conducted at Lincoln Laboratory for this purpose. Special sources were used to generate asynchronous ATCRBS and Mode S reply signals (Fruit) and TCAN/DME squitter and interrogation signals. Synchronous ATCRBS and Mode S reply sequences were also generated to simulate airborne encounters. The performance was evaluated by observing hoe the interference signals either degraded the ability of a TCAS II unit to receive, process, and track the desired synchronous reply sequences, or caused the TCAS II unit to generate false tracks.
READ LESS

Summary

Minimum TCAS II equipment is required to operate reliably in all aircraft densities up to the 0.3 transponder-equipped aircraft per square nautical mile anticipated in the Los Angeles Basin in the year 2000. Prototype TCAS equipment has been developed and shown to be capable of providing reliable surveillance in today's...

READ MORE
Effect of interference on the performance of a minimum TCAS II

Collision avoidance for Naval training aircraft

March 8, 1985
  |
Project Report
Author:
John W. Andrews
…
Published in:
MIT Lincoln Laboratory Report ATC-125
Topic:
collision avoidance
R&D area:
R&D group:

Summary

Lincoln Laboratory was tasked by the FAA to assist the Naval Air Training Command in evaluating the feasibility of using the FAA's TCAS I concept as the document summarizes the results of a brief study and flight test activity conducted to that end. It begins with a review of Lincoln Laboratory's understanding of the nature of the mid-air collision problem at the Naval Air Training Center. This is followed by a brief analysis of a set of documented collisions and near-miss encounters involving aircraft of Navy Training Air Wing 5 at Whiting Naval Air Station in Florida in 1982 and 1983. Experience gained from FAA and Lincoln Laboratory flight tests of similar encounters is reviewed and applied to the Navy encounter data base. This is followed by a review of the results obtained when a Lincoln Laboratory aircraft equipped with a TCAS Experimental Unit (TEU) was flown to Whiting Field to evaluate the ability of TCAS I equipment to perform reliable surveillance in the Naval training environment. Flight test results show that the environment is quite unlike typical civil environments, but that the TCAS surveillance design would be capable of providing a significant degree of protection to Naval trainers.
READ LESS

Summary

Lincoln Laboratory was tasked by the FAA to assist the Naval Air Training Command in evaluating the feasibility of using the FAA's TCAS I concept as the document summarizes the results of a brief study and flight test activity conducted to that end. It begins with a review of Lincoln...

READ MORE
Collision avoidance for Naval training aircraft

TCAS-II: design and validation of the high-traffic-density surveillance subsystem

February 12, 1985
  |
Project Report
Author:
William H. Harman III
…
Published in:
MIT Lincoln Laboratory Report ATC-126
Topic:
collision avoidance
R&D area:
R&D group:

Summary

Lincoln Laboratory, under FAA sponsorship, is developing an airborne collision avoidance system (TCAS II), concentrating primarily on the air-to-air surveillance subsystem. The surveillance functions required are to detect the presence of nearby transponder equipped aircraft, and then generate a surveillance track on each aircraft, issuing range and altitude reports once per second. The development effort from mid-1981 to the present has focused on the surveillance problems associated with high aircraft density. A number of surveillance techniques to deal with the high density environment have been identified and evaluated mainly through airborne measurements. A TCAS II design was synthesized, and this design was subjected to in-flight testing in the Los Angeles Basin using a Boeing 727. Results indicate that the performance objectives have been met.
READ LESS

Summary

Lincoln Laboratory, under FAA sponsorship, is developing an airborne collision avoidance system (TCAS II), concentrating primarily on the air-to-air surveillance subsystem. The surveillance functions required are to detect the presence of nearby transponder equipped aircraft, and then generate a surveillance track on each aircraft, issuing range and altitude reports once...

READ MORE
TCAS-II: design and validation of the high-traffic-density surveillance subsystem

TCAS II ATCRBS surveillance algorithms

January 28, 1985
  |
Project Report
Author:
M. Loren Wood Jr
Published in:
MIT Lincoln Laboratory Report ATC-131
Topic:
surveillance
R&D area:
R&D group:

Summary

The Traffic Alert and Collision Avoidance System (TCAS) has been developed to reduce mid air collisions between transponder equipped aircraft. The TCAS concept encompasses a range of capabilities. TCAS I is a low-cost version which provides traffic advisories only. TCAS II adds vertical resolution advisories and is intended to provide a comprehensive level of separation assurance in all current and predicted airspace environments through the end of this century. Enhanced TCAS II uses more accurate intruder bearing data to allow it to generate horizontal resolution advisories. All three forms of TCAS equipment track aircraft equipped with both the existing Air Traffic Control Radar Beacon System (ATCRBS) transponders and with the new Mode S transponders. A TCAS equipped aircraft makes ATCRBS or Mode S range measurements on nearby aircraft. The ATCRBS or Mode S replies contain the altitude of the aircraft if it has an encoding altimeter. TCAS II uses range rate and altitude rate to decide if a collision is imminent. Therefore the replies from a given aircraft must be tracked and correlated in range and altitude. This report documents surveillance techniques developed by Lincoln Laboratory for use by TCAS II equipment in tracking aircraft equipped with ATCRBS transponders. Specifically, it describes the two tracking algorithms used for ATCRBS replies. One algorithm is for aircraft that report altitude, and the other is for those that do not.
READ LESS

Summary

The Traffic Alert and Collision Avoidance System (TCAS) has been developed to reduce mid air collisions between transponder equipped aircraft. The TCAS concept encompasses a range of capabilities. TCAS I is a low-cost version which provides traffic advisories only. TCAS II adds vertical resolution advisories and is intended to provide...

READ MORE
TCAS II ATCRBS surveillance algorithms
61-70 of 91