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Report on DABS/ATCRBS Field Testing Program

February 13, 1974
  |
Project Report
Author:
John R. Samson
…
Published in:
MIT Lincoln Laboratory Report ATC-31
Topic:
surveillance
R&D area:
R&D group:

Summary

The purpose of this field test program was to verify laboratory measurements of the effect of DABS uplink signal formats on ATCRBS transponders. The DABS interrogations tested were: (i) a combined ATCRBS Mode A/DABS All-Call consisting of a standard Mode A interragation with an additional pulse following the P(3) pulse; (ii) a DABS uplink message transmission consisting of a P(1)-P(2) pulse pair followed by 25 microseconds of 4 megabit per second DPSK data modulation. The timing aspects of these waveforms were selected on the basis of a previous series of laboratory bench tests made in a small cross-section of the ATCRBS transponder population. The results of these field measurements performed on a larger cross-section of field operational ATCRBS transponders agree with the results of the bench testing program: The recommended DABS uplink transmissions result in an effective combined ATCRBS/DABS All-Call mode and minimum triggering of ATCRBS transponders by DABS message transmissions.
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Summary

The purpose of this field test program was to verify laboratory measurements of the effect of DABS uplink signal formats on ATCRBS transponders. The DABS interrogations tested were: (i) a combined ATCRBS Mode A/DABS All-Call consisting of a standard Mode A interragation with an additional pulse following the P(3) pulse...

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Report on DABS/ATCRBS Field Testing Program

The effect of phase error on the DPSK receiver performance

February 4, 1974
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Project Report
Author:
David A. Shnidman
Published in:
MIT Lincoln Laboratory Report ATC-32
Topic:
surveillance
R&D area:
R&D group:

Summary

Several methods of realizing a DPSK receiver use a delay line. Temperature variations cause changes in the delay which, in turn, cause errors in the phase differences between the reference and information signals. The effect of these errors on the performance of an optimum DPSK receiver is studied in this report.
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Summary

Several methods of realizing a DPSK receiver use a delay line. Temperature variations cause changes in the delay which, in turn, cause errors in the phase differences between the reference and information signals. The effect of these errors on the performance of an optimum DPSK receiver is studied in this...

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The effect of phase error on the DPSK receiver performance

Technical Assessment of Satellites for CONUS Air Traffic Control, Executive Summary

January 31, 1974
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Project Report
Author:
Irvin G. Stiglitz
Published in:
MIT Lincoln Laboratory Report ATC-26
Topic:
air traffic control
R&D area:
R&D group:

Summary

A number of satellite system techniques have been suggested as candidates to provide ATC surveillance, communication, and/or navigation service over CONUS. All techniques perform postion determination by multilateration using a constellation of satellites. They can be categorized as follows: 1) Coordinated Aircraft-to-Satellite Techniques (CAST), 2) Random Access Aircraft-to-Satellite Techniques (RAST), and 3) Satellite-to-Aircraft Techniques (SAT). A technical assessment is made of the various techniques with no one particular technique emerging as superior; several feasible alternatives are identified. The assessment indicates that satellite bases techniques for CONUS ATC can be developed without relying on high risk technology. This volume summarizes the results of a technical assessment of all three techniques. The detailed assessment is presented in companion volumes. The assessment has shown that workable systems could be configured using any one of the three techniques without reliance on high risk technology. No one technique has emerged as superior. Rather several viable alternatives have been identified. All techniques appear to require more costly avionics than today's ground-based system.
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Summary

A number of satellite system techniques have been suggested as candidates to provide ATC surveillance, communication, and/or navigation service over CONUS. All techniques perform postion determination by multilateration using a constellation of satellites. They can be categorized as follows: 1) Coordinated Aircraft-to-Satellite Techniques (CAST), 2) Random Access Aircraft-to-Satellite Techniques (RAST)...

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Technical Assessment of Satellites for CONUS Air Traffic Control, Executive Summary

Technical Assessment of Satellites for CONUS Air Traffic Control, Volume I - Coordinated Aircraft-To-Satellite Techniques

January 31, 1974
  |
Project Report
Author:
Richard S. Orr
…
Published in:
MIT Lincoln Laboratory Report ATC-26,I
Topic:
air traffic control
R&D area:

Summary

A number of satellite system techniques have been suggested as candidates to provide ATC surveillance, communication, and/or navigation service over CONUS. All techniques perform postion determination by multilateration using a constellation of satellites. They can be categorized as follows: 1) Coordinated Aircraft-to-Satellite Techniques (CAST), 2) Random Access Aircraft-to-Satellite Techniques (RAST), and 3) Satellite-to-Aircraft Techniques (SAT). A technical assessment is made of the various techniques with no one particular technique emerging as superior; several feasible alternatives are identified. The assessment indicates that satellite bases techniques for CONUS ATC can be developed without relying on high risk technology. This volume deals with CAST, RAST and SAT are treated in companion volumes. A system employing CAST could operate by having each aircraft transmit only in response to interrogation from a satellite. The position of the aircraft is then obtained by multilateration using the arrival times of its response at coordinating the interrogations, mutual interference between different response can be avoided. The critical technical aspects of CAST are explored with special emphasis on signaling formats, avionics, the satellite antenna and susceptibility to jamming.
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Summary

A number of satellite system techniques have been suggested as candidates to provide ATC surveillance, communication, and/or navigation service over CONUS. All techniques perform postion determination by multilateration using a constellation of satellites. They can be categorized as follows: 1) Coordinated Aircraft-to-Satellite Techniques (CAST), 2) Random Access Aircraft-to-Satellite Techniques (RAST)...

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Technical Assessment of Satellites for CONUS Air Traffic Control, Volume I - Coordinated Aircraft-To-Satellite Techniques

Effects of ATCRBS P2 pulses on DABS reliability

January 28, 1974
  |
Project Report
Author:
William H. Harman III
…
Published in:
MIT Lincoln Laboratory Report ATC-20
Topic:
surveillance
R&D area:

Summary

An analytical study is performed to determine the effects of ATCRBS P2 pulses as interference to DABS uplink transmissions. These effects constitute a major component of all uplink error-producing mechanisms that are anticipated to occur in DABS operation. The study is fomulated in a way that includes effects of both receiver noise and P2 pulse interference, where the interference can be received from any of a number of different transmitters at different distances from the receiving aircraft. The model includes the randomness associated with whether or not a particular DABS signal is overlapped by any interference pulse, and also the conditional randomness of error production given that an overlap does occur. In fact, a major portion of the study is the determination of the conditional error probability given the occurrence of an overlap with stated signal-to-interference ratio and stated signal-to-noise ratio. The results are given as the probability of a "miss," where a "miss" is the event that at least one of the bits in the DABS data block is demodulated in error. The study is carried out for both DPSK and PAM which are the two modulation options being considered in the DABS design. Results are given both as general formulas and as evaluations of these fomulas in various specific cases. In these evaluations, the interference environment is based on ATCRBS interrogator locations, transmitter powers, and repetition frequencies as listed in ECAC's IFF Master File. The numerical results are presented graphically to display the dependence on signal level, noise level, and geographical location between Boston and Washington, D.C. A concept referred to as "effective interference tolerance" is introduced, and numerical evaluations are presented to indicate the accuracy of this concept.
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Summary

An analytical study is performed to determine the effects of ATCRBS P2 pulses as interference to DABS uplink transmissions. These effects constitute a major component of all uplink error-producing mechanisms that are anticipated to occur in DABS operation. The study is fomulated in a way that includes effects of both...

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Effects of ATCRBS P2 pulses on DABS reliability

Final report on task A surveillance and communication issues in the transition to a discrete address beacon system

December 26, 1973
  |
Project Report
Author:
Walter I. Wells
…
Published in:
MIT Lincoln Laboratory Report ATC-21
Topic:
surveillance
R&D area:
R&D group:

Summary

This report discusses the transition from the ATCRBS-based surveillance function with voice radio only to a DABS-based surveillance function with integral digital communication capability to support IPC and automation. Recommendations are directed toward alleviation of certain problems already evident and toward preparation for the deployment of DABS beginning in the late 1970s. An evaluation of the present ATCRBS system indicates basic adequacy in the present environment for the current mode of operation of the ATC system. The introduction of automation into the ATC system requires capability in the areas of data link and enhances surveillance reliability for automatic tracking that the DABS system will provide. On this basis it is concluded that the ATCRBS system does not need major modifications to continue its role into the DABS period at locations where the environment and operation will be similar to that presently encountered. A number of recommendations are made regarding radar where new technology can provide significantly enhanced performance at little added cost. The introduction of a digital data link provides many opportunities and challenges. Most of them associated with tactical message handling are being addressed within the DABS program but attention is called to a related set of issues for messages originating from or destined for other than ARTS or NAS (e.g., FSS).
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Summary

This report discusses the transition from the ATCRBS-based surveillance function with voice radio only to a DABS-based surveillance function with integral digital communication capability to support IPC and automation. Recommendations are directed toward alleviation of certain problems already evident and toward preparation for the deployment of DABS beginning in the...

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Final report on task A surveillance and communication issues in the transition to a discrete address beacon system

DABS/ATCRBS transponder bench test program

November 28, 1973
  |
Project Report
Author:
Edmond R. Becotte
…
Published in:
MIT Lincoln Laboratory Report ATC-25
Topic:
surveillance
R&D area:
R&D group:

Summary

The objective of this program was the determination of the effect on ATCRBS transponders of candidate modulation schemes in DABS uplink transmissions. Bench test were conducted on twenty-two different transponder samples, including representative air carrier and general aviation transponders and a military transponder. In this report, individual test procedures are outlined, the reduced data are presented, and some conclusions regarding the selection of the DABS uplink waveforms based upon the data are given. The basis of these conclusions is a DABS design goal of generating the least possible interference to the existing ATCRBS system. In addition to performing tests whose purpose was the direct measurement of response of ATCRBS transponders to candidate DABS uplink waveforms, tests were also run to obtain other link-related characteristic, such as response to non-standard pulses. Conclusions, based upon the test performed, were the DABS signals modulated by either PSK or FSK would be demodulated by a significant fraction of ATCRBS transponders and that there are no feasible PAM pulse widths or spacings which would not be decoded by a significant fraction of ATCRBS transponders. ATCRBS transponder reply probability drops nearly to zero when the DABS message (of arbitrary modulation type) has a duration less than 30 microseconds and is preceded by ATCRBS suppressing preamble. It was further shown that the reliability of suppression al interrogation levels near MTL can be improved by increasing the peak power of the preamble relative to the message.
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Summary

The objective of this program was the determination of the effect on ATCRBS transponders of candidate modulation schemes in DABS uplink transmissions. Bench test were conducted on twenty-two different transponder samples, including representative air carrier and general aviation transponders and a military transponder. In this report, individual test procedures are...

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DABS/ATCRBS transponder bench test program

Provisional Signal Formats for the Discrete Address Beacon System

November 9, 1973
  |
Project Report
Author:
Paul R. Drouilhet Jr
Published in:
MIT Lincoln Laboratory Report ATC-30
Topic:
surveillance
R&D area:
R&D group:

Summary

This document specifies provisional DABS signal formats, i.e., the characteristics of the "signals-in-space"which for the DABS interrogations and replies. Also included is a discussion of the utilization of the described formats to effect the surveillance and data link communication functions for which DABS has been designed. These signal formats will be used in the design and construction of engineering development model transponders and interrogators for prototype system test and evaluation at NAFEC during Phase II of the DABS Development Program; and, with modifications resulting from this test and evaluation effort, will form the basis for the operational implementation of DABS.
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Summary

This document specifies provisional DABS signal formats, i.e., the characteristics of the "signals-in-space"which for the DABS interrogations and replies. Also included is a discussion of the utilization of the described formats to effect the surveillance and data link communication functions for which DABS has been designed. These signal formats will...

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Provisional Signal Formats for the Discrete Address Beacon System

The Discrete Address Beacon System (DABS)

November 8, 1973
  |
Conference Paper
Author:
Herbert G. Weiss
…
Published in:
IEEE Northeast Electronic Research and Engineering Mtg., NEREM, 8 November 1973.
Topic:
air traffic control
R&D area:
R&D group:

Summary

The requirement for additional automation in the air traffic control process has placed new emphasis on the need for high quality surveillance data and for a ground-to-aircraft data link. The ATCRBS beacon system has proven a valuable complement to radar because it provides the ground controller with position, identity, and altitude data that is not contaminated by ground and weather clutter. However, the growing number of beacon-equipped aircraft and ground interrogators and the inherent self-interference limitations of the ATCRBS beacon system have motivated the need for a more reliable and flexible beacon system. The 1969 the Air Traffic Control Advisory Committee recommended the development of such an improved system which they named the Discrete Address Beacon System (DABS), incorporating both surveillance and a data link. Since 1971, M.I.T. Lincoln Laboratory, under the sponsorship of the FAA, has been investigating various DABS design options.
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Summary

The requirement for additional automation in the air traffic control process has placed new emphasis on the need for high quality surveillance data and for a ground-to-aircraft data link. The ATCRBS beacon system has proven a valuable complement to radar because it provides the ground controller with position, identity, and...

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The Discrete Address Beacon System (DABS)

Empirical assessment of ATCRBS

October 31, 1973
  |
Project Report
Author:
Alan G. Cameron
…
Published in:
MIT Lincoln Laboratory Report ATC-16
Topic:
surveillance
R&D area:
R&D group:

Summary

This report discusses the operational performance of the FAA ATCRBS system, as determined from data extracted from the ARTS III digital processing system. Data was gathered from several sites including Andrews Air Force Base, (Md.), Logan International Airport (Boston, Mass.), and McCarran International Airport (Las Vegas, Nevada). Quantitative performance data, as well as discussion of the problem area and possible techniques and procedures for its solution, are provided in the areas of weak/broken targets, false targets, synchronous garble, interference, erroneous decoding, improper defruiter operation, and insufficient angular resolution. A discussion of improvements that can alleviate some of the deficiences of today's secondary radar (ATCRBS) system is included.
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Summary

This report discusses the operational performance of the FAA ATCRBS system, as determined from data extracted from the ARTS III digital processing system. Data was gathered from several sites including Andrews Air Force Base, (Md.), Logan International Airport (Boston, Mass.), and McCarran International Airport (Las Vegas, Nevada). Quantitative performance data...

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Empirical assessment of ATCRBS
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