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The tradeoff between delay and TASI advantage in a packetized speech multiplexer

November 1, 1979
  |
Journal Article
Author:
Clifford J. Weinstein
…
Published in:
IEEE Trans. on Commun., Vol. COM-27, No. 11, November 1979, pp. 1716-20.
Topic:
signal processing
R&D area:
R&D group:

Summary

A packetized speech multiplexer differs from a circuit-switched TASI system in that the presence of a packet buffer allows a tradeoff where the TASI advantage can be increased at a cost in packet delay. This tradeoff is investigated via a simulation. Results are presented to show the relations between TASI advantage and delay, for both an average delay criterion and a maximum delay criterion. It is shown that, particularly for the case where small numbers of talkers are multiplexed, the packetized system offers significant improvements in TASI advantage over the conventional circuit-switched multiplexer, at modest costs in packet delay.
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Summary

A packetized speech multiplexer differs from a circuit-switched TASI system in that the presence of a packet buffer allows a tradeoff where the TASI advantage can be increased at a cost in packet delay. This tradeoff is investigated via a simulation. Results are presented to show the relations between TASI...

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The tradeoff between delay and TASI advantage in a packetized speech multiplexer

Air traffic density and distribution measurements

May 3, 1979
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Project Report
Author:
William H. Harman III
Published in:
MIT Lincoln Laboratory Report ATC-80
Topic:
air traffic control
R&D area:
R&D group:

Summary

Results of measurements to determine peak air traffic densities, the spatial distribution of air traffic, and its variation with time, in the Los Angeles Basin and at several locations from Boston to Washington, D.C. are reported. These measurements include only ATCRBS-transponder equipped aircraft. LA Basin traffic densities are shown to be significantly higher than those measured at any other location. The time- and spatial-average density over a circular region of 10 nmi radius reaches a peak value of 0.1 aircraft per sq. nmi in LA. Under comparable conditions the density in Washington, Philadelphia, and Boston reaches 0.02 to 0.04 aircraft per sq. nmi. These measurements, made in 1976, were compared with the LA Basin Standard Traffic Model as to spatial distribution of traffic and absolute density. The results show that the model and the measurement differ by a scale factor of 5:1 (with density being greater in the model) but otherwise agree closely in spatial distribution.
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Summary

Results of measurements to determine peak air traffic densities, the spatial distribution of air traffic, and its variation with time, in the Los Angeles Basin and at several locations from Boston to Washington, D.C. are reported. These measurements include only ATCRBS-transponder equipped aircraft. LA Basin traffic densities are shown to...

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Air traffic density and distribution measurements

MLS Multipath Studies, Phase 3, Volume I: Overview and Propagation Model Validation/Refinement Studies

April 25, 1979
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Project Report
Author:
James E. Evans
…
Published in:
MIT Lincoln Laboratory Report ATC-88,I
Topic:
surveillance
R&D area:
R&D group:

Summary

This report presents work done during phase 3 of the US national Microwave Landing System (MLS) program toward developing a computer simulation model of the MLS multipath effects, the experimental validation ot the model, and the application of the model to investigate multipath performance of ICAO proposals for the new approach and landing guidance system. This first volume of the report presents an overview of the overall simulation results as well as a description of the refined mathematical models and validation of the propagation portion of the simulation. Specific propagation topics include: 1) preliminary results for validation of models for reflections from rough and/or rising terrain based on L-band field data. 2) validation of the models for building reflections based on field measurements at a number of operational airports. 3) validation and refinement of the models for angle guidance system shadowing by obstacles such as buildings and other objects.
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Summary

This report presents work done during phase 3 of the US national Microwave Landing System (MLS) program toward developing a computer simulation model of the MLS multipath effects, the experimental validation ot the model, and the application of the model to investigate multipath performance of ICAO proposals for the new...

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MLS Multipath Studies, Phase 3, Volume I: Overview and Propagation Model Validation/Refinement Studies

The DABS calibration performance monitoring equipment

March 23, 1979
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Project Report
Author:
James C. Anderson
Published in:
MIT Lincoln Laboratory Report ATC-89
Topic:
surveillance
R&D area:
R&D group:

Summary

The Discrete Address Beacon System (DABS) Calibration Performance Monitor Equipment (CPME) is a special DABS transponder designed for installation at a fixed site visible to one or more DABS beacon sensors. The CPME is required for DABS sensor monopulse accuracy tests and for calibration of the sensor off-boresite azimuth look-up table. In addition, the CPME provides tests for DABS link integrity, by storing an uplink message and parroting it back upon command from the sensor. This document contains all information necessary to obtain a general understanding of the CPME system and its operation. Detailed information necessary for repair of the equipment is not contained in this document, but is supplied with each CPME system.
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Summary

The Discrete Address Beacon System (DABS) Calibration Performance Monitor Equipment (CPME) is a special DABS transponder designed for installation at a fixed site visible to one or more DABS beacon sensors. The CPME is required for DABS sensor monopulse accuracy tests and for calibration of the sensor off-boresite azimuth look-up...

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The DABS calibration performance monitoring equipment

The Aircraft Reply and Interference Environment Simulator (ARIES) volume 1: principles of operation

March 22, 1979
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Project Report
Author:
Michael Goon
…
Published in:
MIT Lincoln Laboratory Report ATC-87,I
Topic:
simulation
R&D area:
R&D group:

Summary

The Aircraft Reply and Interference Environment Simulator (ARIES) makes possible the performance assessment of a Discrete Address Beacon System (DABS) sensor under its specified maximum aircraft load. To do this ARIES operates upon a taped traffic model to generate simulated aircraft replies and fruit, feeding them to the sensor at RF. Support documentation for ARIES, of which this is the first volume, consists of: Volume 1: Principles of Operation Volume 2: Appendices to the Principles of Operation Volume 3: Programmer's Manual The Principles of Operation details the operation of ARIES hardware and software. Descriptive information, supported by block diagrams, simplified schematic diagrams and flow diagrams, is provided sufficient to permit a thorough understanding of ARIES operation.
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Summary

The Aircraft Reply and Interference Environment Simulator (ARIES) makes possible the performance assessment of a Discrete Address Beacon System (DABS) sensor under its specified maximum aircraft load. To do this ARIES operates upon a taped traffic model to generate simulated aircraft replies and fruit, feeding them to the sensor at...

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The Aircraft Reply and Interference Environment Simulator (ARIES) volume 1: principles of operation

The Aircraft Reply and Interference Environment Simulator (ARIES) volume 3: programmer's manual

March 22, 1979
  |
Project Report
Author:
Michael Goon
…
Published in:
MIT Lincoln Laboratory Report ATC-87,III
Topic:
air traffic control
R&D area:
R&D group:

Summary

The Aircraft Reply and Interference Environment Simulator (ARIES) makes possible the performance assessment of a Discrete Address Beacon System (DABS) sensor under its specified maximum aircraft load. To do this ARIES operates upon a taped traffic model to generate simulated aircraft replies and fruit, feeding them to the sensor at RF. Support documentation for ARIES, of which this is the second volume, consists of: Volume 1: Principles of Operation Volume 2: Appendices to the Principles of Operation Volume 3: Programmer's Manual The ARIES Programmer's Manual describes the operation, signal formats and protocols of the Lincoln Laboratory built input/output devices controlled by the Eclipse computer. The descriptions are primarily concerned with the logic of the interface boards that reside in the computer chassis and the formats of the words transferred to and from the computer. The logic of the devices themselves is described only to the extent necessary to understand the interface protocols and data formats.
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Summary

The Aircraft Reply and Interference Environment Simulator (ARIES) makes possible the performance assessment of a Discrete Address Beacon System (DABS) sensor under its specified maximum aircraft load. To do this ARIES operates upon a taped traffic model to generate simulated aircraft replies and fruit, feeding them to the sensor at...

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The Aircraft Reply and Interference Environment Simulator (ARIES) volume 3: programmer's manual

The Aircraft Reply and Interference Environment Simulator (ARIES), volume 2: appendices to the principles of operation

March 22, 1979
  |
Project Report
Author:
Michael Goon
…
Published in:
MIT Lincoln Laboratory Report ATC-87,II
Topic:
simulation
R&D area:
R&D group:

Summary

The Aircraft Reply and Interference Environment Simulator (ARIES) makes possible the performance assessment of a Discrete Address Beacon System (DABS) sensor under its specified maximum aircraft load. To do this ARIES operates upon a taped traffic model to generate simulated aircraft replies and fruit, feeding them to the sensor at RF. Support documentation for ARIES, of which this is the second volume, consists of: Volume 1: Principles of Operation Volume 2: Appendices to the Principles of Operation Volume 3: Programmer's Manual The Appendices to the Principles of Operation is comprised of a set of technical articles providing (a) explanations of design and programming aspects of the ARIES system not covered in the main volume, (b) detailed data format and data structure definitions, (c) detailed explanations of the meaning of ARIES error messages, and (d) an analysis of certain effects to be expected when more than one ARIES simulator are interconnected.
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Summary

The Aircraft Reply and Interference Environment Simulator (ARIES) makes possible the performance assessment of a Discrete Address Beacon System (DABS) sensor under its specified maximum aircraft load. To do this ARIES operates upon a taped traffic model to generate simulated aircraft replies and fruit, feeding them to the sensor at...

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The Aircraft Reply and Interference Environment Simulator (ARIES), volume 2: appendices to the principles of operation

Uplink ATCRBS environment measurements along the Boston-Washington corridor, volume 2: interrogator characteristics

February 28, 1979
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Project Report
Author:
Ferenc Nagy Jr
Published in:
MIT Lincoln Laboratory Report ATC-83,II
Topic:
surveillance
R&D area:
R&D group:

Summary

Airborne measurements of the Air Traffic Control Radar Beacon System (ATCRBS) 1030 MHz uplink environment due to ATC ground interrogators are described. The measurements were made using a special purpose airborne sensor-recorder during a flight from Boston to Washington (at 8500 feet) and back (at 17,500 feet) on 16 December 1977. Data were recorded at 24 locations between Boston and Washington. Volume 1 of this report summarized the measured distributions of pulse, interrogation, and suppression rates with received power. This volume presents specific characteristics of the sources of the interrogations observed from the air dUring this flight. These characteristics include the identities of 46 of the interrogators, the approximate locations of 22 unidentified interrogators, the interrogation repetition interval (PRI), scan period, and mode interlace of all interrogators, and the radiated P1, P2, and P3 levels in the form of antenna patterns for six selected interrogators. It was found that approximately 40% of the interrogators employ the standard AAC or 2ACA mode interlaces while 20% transmit no Mode C interrogations. The distributions of PRI's and scan periods were found to be relatively free of bunching which would cause undesired synchronization effects. The antenna plots measured from the air show relatively large scan to scan variations due to aircraft motion. In addition, some of the interrogator sites were found to suffer from reflections and sidelobe punch-through effects.
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Summary

Airborne measurements of the Air Traffic Control Radar Beacon System (ATCRBS) 1030 MHz uplink environment due to ATC ground interrogators are described. The measurements were made using a special purpose airborne sensor-recorder during a flight from Boston to Washington (at 8500 feet) and back (at 17,500 feet) on 16 December...

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Uplink ATCRBS environment measurements along the Boston-Washington corridor, volume 2: interrogator characteristics

Automated tracking for aircraft surveillance radar systems

January 1, 1979
  |
Conference Paper
Author:
Robert M. O'Donnell
…
Published in:
IEEE Trans. Aerosp. Electron. Syst., Vol. AES-15, No. 4, July 1979, pp. 508-517.
Topic:
detection systems
R&D area:
R&D group:

Summary

An improved moving target detector (MTD) (a digital signal processor) has been designed, constructed, and tested which successfully rejects all forms of radar clutter while providing reliable detection of all aircraft within the coverage of the radar. The MTD is being tested on both terminal and enroute surveillance radars for the FAA. This processor has been integrated with automatic tracking algorithms to give complete rejection of ground clutter, heavy precipitation, and angels (birds).
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Summary

An improved moving target detector (MTD) (a digital signal processor) has been designed, constructed, and tested which successfully rejects all forms of radar clutter while providing reliable detection of all aircraft within the coverage of the radar. The MTD is being tested on both terminal and enroute surveillance radars for...

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Automated tracking for aircraft surveillance radar systems

Airborne measurements of ATCRBS fruit

October 3, 1978
  |
Project Report
Author:
William H. Harman III
Published in:
MIT Lincoln Laboratory Report ATC-84
Topic:
surveillance
R&D area:
R&D group:

Summary

Airborne measurements of ATCRBS fruit (asynchronous replies from ATCRBS transponders) are described. These measurements were undertaken to provide a more firm basis for assessing the interference impact of ATCRBS fruit on airborne 1090 MHz receivers (as in BCAS). Fruit rate measurements were performed with an instrumented aircraft flying along the East Coast from Boston to Washington and in the Los Angeles Basin. The results of these measurements are reported here, with fruit rates given as a function of altitude, geographical location, and receiver threshold, for receptions on both top-mounted and bottom-mounted aircraft antenna. The highest observed fruit rates, approximately 10,000 replies/sec, occurred in the LA Basin. To complement the measurements, a first-order fruit prediction model is defined. Predictions of this model are compared with the measurements, generally showing favorable agreement in absolute fruit rate, in power distribution, and in the functional dependence on traffic density.
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Summary

Airborne measurements of ATCRBS fruit (asynchronous replies from ATCRBS transponders) are described. These measurements were undertaken to provide a more firm basis for assessing the interference impact of ATCRBS fruit on airborne 1090 MHz receivers (as in BCAS). Fruit rate measurements were performed with an instrumented aircraft flying along the...

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Airborne measurements of ATCRBS fruit
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