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The DABS calibration performance monitoring equipment

March 23, 1979
  |
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
  |
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
  |
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

A phrase recognizer using syllable-based acoustic measurements

October 1, 1978
  |
Journal Article
Author:
Don H. Johnson
…
Published in:
IEEE Trans. Acoust. Speech Signal Process., Vol. ASSP-26, No. 5, October 1978, pp. 409-418.
Topic:
speech recognition
R&D area:
R&D group:

Summary

A system for the recognition of spoken phrases is described. The recognizer assumes that the input utterance contains one of a known set of allowable phrases, which may be spoken within a longer carrier sentence. Analysis is performed on a syllable-by-syllable basis with only the strong syllables considered in the recognition process. Each strong syllable is represented in terms of a set of distinguishing acoustic measurements taken at time points in and around the syllable nucleus. Phrases are represented as sequences of strong syllables. All parameters used in recognition are derived from LPC coefficients. Input speech is limited to 3.3 kHZ upper frequency. Recognition is completed within 1-3 s after the utterance is spoken. An interactive training facility allows flexible composition of key phrase sets. Testing was performed for a number of phrase sets each containing ten or fewer phrases, and included equal numbers of talkers used in training and talkers not used in training. Average phrase recognition accuracy was 95 percent when parameters were derived from unquantized (i.e., 16 bit) LPC coefficients and 90 percent when the LPC coefficients were transmitted to the recognizer across the ARPA network at 3500 bits/s. The recognizer has been incorporated into a user interface system where the parameters required to set up a point-to-point ARPANET voice connection can be established remotely by voice.
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Summary

A system for the recognition of spoken phrases is described. The recognizer assumes that the input utterance contains one of a known set of allowable phrases, which may be spoken within a longer carrier sentence. Analysis is performed on a syllable-by-syllable basis with only the strong syllables considered in the...

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A phrase recognizer using syllable-based acoustic measurements

Uplink ATCRBS environment measurements along the Boston-Washington Corridor, volume 1: the RF environment

June 27, 1978
  |
Project Report
Author:
Ferenc Nagy Jr
Published in:
MIT Lincoln Laboratory Report ATC-83,I
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 and processed to obtain distributions of pulse, interrogation, and suppression rates with received power. The most numerous contributors to the uplink pulse environment are omnidirectionally radiated suppression pulses. The overall average suppression rate is approximately 600 per second. The suppression rate is relatively independent of altitude but there are wide variations in the suppression rate from one location to another. Interrogation rates increase with altitude but do not vary significantly from location to location except near interrogators without sidelobe suppression. The overall average rate of receipt of Mode A plus Mode C interrogations is approximately 75 per second at an altiude of 8500 feet and 100 per second at an altitude of 17,500 feet.
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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 1: the RF environment

Variance and spectra of angle-of-arrival and Doppler fluctuations caused by ionospheric scintillation

May 1, 1978
  |
Journal Article
Author:
Robert K. Crane
Published in:
J. of Geophysical Research, May 1, 1978, Vol. 83, No. A5, pp. 2091-2102.
Topic:
radar
R&D area:
R&D group:

Summary

The variance and spectra of angle-of-arrival and Doppler fluctuations were estimated by using 150- and 400-MHz transmissions from the low-orbiting U.S. Navy navigation satellites observed at the Millstone Hill radar facility. A theoretical model for the variance and spectra was also constructed by using the Rytov approximation and a power law power spectrum model for the electron density fluctuations. The model provided a means for the estimation of both the axial ratio and the location of the lower edge of the irregularity region, using only angle-of-arrival and Doppler observations made at a single location. Good agreement was obtained between the model estimates and observations. Analysis of data from two magnetic storms revealed simultaneous occurrences of E region and F region irregularities at invariant latitudes north of 56°.
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Summary

The variance and spectra of angle-of-arrival and Doppler fluctuations were estimated by using 150- and 400-MHz transmissions from the low-orbiting U.S. Navy navigation satellites observed at the Millstone Hill radar facility. A theoretical model for the variance and spectra was also constructed by using the Rytov approximation and a power...

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Variance and spectra of angle-of-arrival and Doppler fluctuations caused by ionospheric scintillation
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