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Verification of DABS sensor surveillance performance (ATCRBS Mode) at typical ASR sites throughout CONUS

December 20, 1977
  |
Project Report
Author:
Walter I. Wells
Published in:
MIT Lincoln Laboratory Report ATC-79
Topic:
surveillance
R&D area:
R&D group:

Summary

A Transportable Measurement Facility (TMF) incorporating antenna, r-f, and reply processing elements of a Discrete Address Beacon System (DABS) sensor has been sited at, and in the vicinity of, several FAA terminal ASR's throughout the United States. Data collected at these sites have been thoroughly analyzed to verify the design of the DABS sensor and to establish the need for design refinements. This report presents the results that pertain to DABS and ATCRBS Mode range and azimuth accuracy and to the total ATCRBS Mode reply processing performance, It is shown that both range and azimuth accuracies for the DABS sensor are a factor of four to five better than those provided by existing ARTS (BI-4) interrogators, and that the average blip/scan ratio is 98% or better, dropping only a few percentage points in crossing track situations.
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Summary

A Transportable Measurement Facility (TMF) incorporating antenna, r-f, and reply processing elements of a Discrete Address Beacon System (DABS) sensor has been sited at, and in the vicinity of, several FAA terminal ASR's throughout the United States. Data collected at these sites have been thoroughly analyzed to verify the design...

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Verification of DABS sensor surveillance performance (ATCRBS Mode) at typical ASR sites throughout CONUS

DABS sensor interactions with ATC facilities

April 22, 1976
  |
Project Report
Author:
David Reiner
…
Published in:
MIT Lincoln Laboratory Report ATC-51
Topic:
surveillance
R&D area:
R&D group:

Summary

This document presents, on a functional level, the interactions that occur between a DABS sensor and an ATC facility (terminal or enroute) in order to make full use of the capabilities provided by the addition of DABS sensors to the ATC system. There are three functions of the interactions: (1) handle surveillance reports from the DABS site, (2) handle the two-way digital communications messages between pilots and controllers, and (3) handle a variety of control data messages between the two sites. For each kind of interaction, the actions taken by the DABS sensor are summerized, the messages involved in the transaction are defined, and suggestions are made concerning possible appropriate actions by the ATC facility. The latter include message generation and display, data processing, and controller and system manager activities.
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Summary

This document presents, on a functional level, the interactions that occur between a DABS sensor and an ATC facility (terminal or enroute) in order to make full use of the capabilities provided by the addition of DABS sensors to the ATC system. There are three functions of the interactions: (1)...

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DABS sensor interactions with ATC facilities

Design validation of the network management function

February 2, 1976
  |
Project Report
Author:
Patricia H. Mann
…
Published in:
MIT Lincoln Laboratory Report ATC-54
Topic:
air traffic control
R&D area:
R&D group:

Summary

This document presents the results of a major design validation effort of the Network Management function described in the DABS Engineering Requirements document. The design validation is based on simulation of a DABS network of three sensors interacting with airborne traffic of approximately 800 aircraft
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Summary

This document presents the results of a major design validation effort of the Network Management function described in the DABS Engineering Requirements document. The design validation is based on simulation of a DABS network of three sensors interacting with airborne traffic of approximately 800 aircraft

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Design validation of the network management function

Impact of obstacle shadows on monopulse azimuth estimate [project report]

July 17, 1975
  |
Project Report
Author:
Alex Spiridon
Published in:
MIT Lincoln Laboratory Report ATC-50
Topic:
surveillance
R&D area:
R&D group:

Summary

Obstacle shadows, within view of a sensor using monopulse azimuth estimate, cause an error in the azimuth estimate. This report discusses the azimuth error as a function of obstacle dimension and position, and the sensor antenna illumination.
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Summary

Obstacle shadows, within view of a sensor using monopulse azimuth estimate, cause an error in the azimuth estimate. This report discusses the azimuth error as a function of obstacle dimension and position, and the sensor antenna illumination.

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Impact of obstacle shadows on monopulse azimuth estimate [project report]

Plan for flight testing intermittent positive control

June 1, 1975
  |
Project Report
Author:
John W. Andrews
…
Published in:
MIT Lincoln Laboratory Report ATC-46
Topic:
air traffic control
R&D area:
R&D group:

Summary

Intermittent Positive Control is an automated aircraft collision avoidance system requiring the participation of the aircraft pilots involved. The operational interface between pilots and the IPC system is being evaluated in a series of live flight tests. The Lincoln Laboratory DABS Experimental Facility, augmented to include the IPC function, is the test bed for these evaluation flights. This document described the objectives and methods of the IPC flight testing being conducted by Lincoln Laboratory.
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Summary

Intermittent Positive Control is an automated aircraft collision avoidance system requiring the participation of the aircraft pilots involved. The operational interface between pilots and the IPC system is being evaluated in a series of live flight tests. The Lincoln Laboratory DABS Experimental Facility, augmented to include the IPC function, is...

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Plan for flight testing intermittent positive control

Network management

May 16, 1975
  |
Project Report
Author:
Herman F. Vandevenne
Published in:
MIT Lincoln Laboratory Report ATC-45
Topic:
air traffic control
R&D area:
R&D group:

Summary

This report provides a discussion of the design of the DABS network management function. Network management is responsible for the interaction between the local sensor and the adjacent connected sensors. Based on a dynamic interpretation of the coverage map and the status of the network, network management determines (a) the coverage responsibility of the local sensor, (b) which other sensors are covering the same area, and (c) which of the sensors has principal data link responsibility. Interaction is effected through message exchange over ground communication links connecting the DABS sensors.
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Summary

This report provides a discussion of the design of the DABS network management function. Network management is responsible for the interaction between the local sensor and the adjacent connected sensors. Based on a dynamic interpretation of the coverage map and the status of the network, network management determines (a) the...

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Network management

DABS link performance considerations

April 28, 1975
  |
Project Report
Author:
Gary J. Schlieckert
Published in:
MIT Lincoln Laboratory Report ATC-41
Topic:
surveillance
R&D area:
R&D group:

Summary

The DABS link performance is computed using the present values for the system operating parameters and the available models that describe environment and aircraft antenna effects. The various fade mechanisms are described, and a statistical determination of performance is proposed. The performance is computed for various sets of conditions including different ground antennas, aircraft maneuvers, antenna obstructions and the performance when aircraft are in the cone of silence. The DABS link is found to have very good overall performance with only small regions of reduced reliability that are at low angles or due to maneuvers. Those missed replies due to maneuvers are found to be sporadic from scan to scan.
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Summary

The DABS link performance is computed using the present values for the system operating parameters and the available models that describe environment and aircraft antenna effects. The various fade mechanisms are described, and a statistical determination of performance is proposed. The performance is computed for various sets of conditions including...

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DABS link performance considerations

DABS channel management

January 8, 1975
  |
Project Report
Author:
Edward J. Kelly
Published in:
MIT Lincoln Laboratory Report ATC-43
Topic:
surveillance
R&D area:
R&D group:

Summary

This report provides a full discussion of the design of the DABS channel management function. Channel management regulates all activity on the RF channel, scheduling ATCRBS interrogations and DABS roll-call interrogations and replies. Channel management arranges for multiple interrogations when required to satisfy both the surveillance and the communications functions of the sensor, and for reinterrogations in the event of link failure. The report consists of three major parts: Part I, Channel Control; Part II, Roll-Call Scheduling; and Part III, Transaction Preparation, Target List Update, and Transaction Update. Together they encompass the five basic subfunctions of channel management.
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Summary

This report provides a full discussion of the design of the DABS channel management function. Channel management regulates all activity on the RF channel, scheduling ATCRBS interrogations and DABS roll-call interrogations and replies. Channel management arranges for multiple interrogations when required to satisfy both the surveillance and the communications functions...

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DABS channel management

DABS: A System Description

November 18, 1974
  |
Project Report
Author:
Paul R. Drouilhet Jr
Published in:
MIT Lincoln Laboratory Report ATC-42
Topic:
surveillance
R&D area:
R&D group:

Summary

The Discrete Address Beacon System (DABS) is a cooperative surveillance and communication system for air traffic control. It employs ground-based sensors (interrogators) and airborne transponders. Ground-to-air and air-to-ground data-link communications are accommodated integrally with the surveillance interrogations and replies. DABS has been designed as an evolutionary replacement for the current Air Traffic Control Radar Beacon System (ATCRBS) to provide the enhanced surveillance and communication capability required for air traffic control in the 1980s and 1990s. Compatibility with ATCRBS has been emphasized to permit an extended, economical transition. A principal feature of DABS is that each aircraft is assigned a unique address code. Using this unique code, interrogations can be directed to a particular aircraft, and replies unambiguously identified. Channel interference is minimized because a sensor can limit its interrogation to targets of interest. In addition, by proper timing of interrogations, replies from closely-spaced aircraft can be received without mutual interference. The unique address in each intertogation and reply also permits the inclusion of data-link messages to or from a particular aircraft. DABS uses the same frequencies for interrogations and replies as ATCRBS (1030 and 1090 MHz, respectively). The DABS interrogation is transmitted using DPSK at a 4 Mbps rate, and comprises 56 or 112 bits including the 24-bit discrete address. The reply also comprises 56 or 112 bits including address, and is transmitted at 1 Mbps using binary pulse-position modulation. Coding is used on both interrogations and replies to protect against errors. The DABS sensor provides surveillance of DABS- and ATCRBS-equipped aircraft, and data-link service to DABS aircraft. In addition, it performs radar/beacon correlation of radar target reports from a collocated radar. The DABS sensor transmits surveillance data to, and exchanges messages with, air traffic control facilities (TRACONs and ARTCCs) via low-rate digital circuits. The DABS sensor communicates directly with adjacent DABS Sensors to hand off targets and to provide surveillance and communication backup in the event of momentary link failures. Each DABS service to DABS-equipped aircraft via the ground-air data link. The DABS transponder replies to both ATCRBS and DABS interrogations, and interfaces with a variety of data-link messaged display and input devices. The rms surveillance accuracy provided by DABS is the order of 100 ft and 0.1 degree in range and azimuth, respectively. Surveillance and data-link communication capacities exceed by a substantial margin projected ATC requirements through the remainder of this century.
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Summary

The Discrete Address Beacon System (DABS) is a cooperative surveillance and communication system for air traffic control. It employs ground-based sensors (interrogators) and airborne transponders. Ground-to-air and air-to-ground data-link communications are accommodated integrally with the surveillance interrogations and replies. DABS has been designed as an evolutionary replacement for the current...

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DABS: A System Description

The influence of surveillance system parameters on automated conflict detection and resolution

November 29, 1972
  |
Project Report
Author:
John W. Andrews
…
Published in:
MIT Lincoln Laboratory Report ATC-15
Topic:
collision avoidance
R&D area:
R&D group:

Summary

The effects of sensor accuracy, data rate, and message delivery delay upon automated conflict detection,and resolution processing is analyzed and particular considerations for DABS/IPC operation are discussed. Various options in the design of the algorithmic logic are enumerated and a particular logic is chosen for quantitative inspection. Performance sensitivity calculations for the conflict detection and command generation functions are then presented. The influence of algorithmic logic and traffic environment upon surveillance requirements is delineated.
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Summary

The effects of sensor accuracy, data rate, and message delivery delay upon automated conflict detection,and resolution processing is analyzed and particular considerations for DABS/IPC operation are discussed. Various options in the design of the algorithmic logic are enumerated and a particular logic is chosen for quantitative inspection. Performance sensitivity calculations...

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The influence of surveillance system parameters on automated conflict detection and resolution
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