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IPC design validation and flight testing final report

March 31, 1978
  |
Project Report
Author:
John W. Andrews
…
Published in:
MIT Lincoln Laboratory Report ATC-85
Topic:
air traffic control
R&D area:
R&D group:

Summary

A series of flight tests were conducted to evaluate the collision avoidance system known as Intermittent Positive Control (subsequently re-named Automatic Traffic Advisory and Resolution Service, ATARS). These tests involved both professional test pilots and subject pilots selected from the aviation community. This report includes analysis of the collision avoidance algorithm, pilot visual acquisition performance, and pilot reaction to avoidance instructions.
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Summary

A series of flight tests were conducted to evaluate the collision avoidance system known as Intermittent Positive Control (subsequently re-named Automatic Traffic Advisory and Resolution Service, ATARS). These tests involved both professional test pilots and subject pilots selected from the aviation community. This report includes analysis of the collision avoidance...

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IPC design validation and flight testing final report

Automating radars for air traffic control

February 2, 1978
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Conference Paper
Author:
Charles E. Muehe
…
Published in:
Electronic Show and Convention, Electro, Boston, MA, 23-25 March 1978.
Topic:
air traffic control
R&D area:
R&D group:

Summary

Developments in digital signal processing over the past few years have improved the detection and false alarm properties of air surveillance radars to such an extent that automatic radar tracking of all aircraft within the radar's coverage volume has become a reality. This paper derives the radar requirements to support tracking in a fully automated air traffic control system.
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Summary

Developments in digital signal processing over the past few years have improved the detection and false alarm properties of air surveillance radars to such an extent that automatic radar tracking of all aircraft within the radar's coverage volume has become a reality. This paper derives the radar requirements to support...

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Automating radars for air traffic control

Interferometer design for elevation angle estimation

August 21, 1977
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Journal Article
Author:
Robert J. McAulay
Published in:
IEEE Trans. Aerosp. Electron. Syst., Vol. AES-13, No. 5, September 1977, pp. 486-503.
Topic:
air traffic control
R&D area:
R&D group:

Summary

Radars that are developed for the purpose of monitoring aircraft landings in the terminal air traffic control system can be designed to exploit the relatively high signal-to-noise ratio that characterizes the power budgets calculated for such a link. An interferometer using a pair of low gain antennas can be used to obtain passive coverage over a target azimuth and elevation sector. A large baseline can be used to obtain the desired elevation angle estimation accuracy. In this paper an optimal tradeoff between the width of the subarray aperture and the width of the interferometer baseline is performed that achieves a specified elevation angle estimation error while minimizing the overall height of the interferometer configuration. The algorithm searches through the class of antenna patterns that can be synthesized from so-called finite impulse response, linear phase digital filters. For the specific problem of designing an elevation sensor for monitoring landing aircraft on final approach, the elevation angle can be estimated with no more than 1-mrad rms error when the aircraft is within 60 azimuth, 2.5 to 40 elevation, using two 7-wavelength subarray antennas spaced 8 wave-lengths apart. The design of a separate sensor for resolving the interferometer ambiguities is formulated as a hypothesis testing problem and solved using statistical decision theory. A bound on the probability of an ambiguity error is derived that accounts for the effects of ground reflection multipath and receiver noise.
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Summary

Radars that are developed for the purpose of monitoring aircraft landings in the terminal air traffic control system can be designed to exploit the relatively high signal-to-noise ratio that characterizes the power budgets calculated for such a link. An interferometer using a pair of low gain antennas can be used...

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Interferometer design for elevation angle estimation

Coaxial magnetron spectra and instabilities

June 24, 1977
  |
Project Report
Author:
Melvin Labitt
Published in:
MIT Lincoln Laboratory Report ATC-74
Topic:
surveillance
R&D area:
R&D group:

Summary

Application of advanced radar clutter rejection techniques to FAA airport surveillance and enroute radars is constrained by inherent instabilities and spectral properties of the device used with the radar transmitter to generate high level RF pulse energy, and the degree to which its spectrum can be influenced by the circuit in which it operates. Coaxial magnetrons are believed to be spectrally pure, controllable and stable, and to embody other characteristics such as long life, which make them attractive replacements for the magnetrons presently employed. This report summarizes the results of extensive measurements made on a conventional S-band magnetron (presently employed in the ASR-7 radar) and a coaxial magnetron of equivalent pulse and power rating to compare their instabilities and spectral properties.
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Summary

Application of advanced radar clutter rejection techniques to FAA airport surveillance and enroute radars is constrained by inherent instabilities and spectral properties of the device used with the radar transmitter to generate high level RF pulse energy, and the degree to which its spectrum can be influenced by the circuit...

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Coaxial magnetron spectra and instabilities

Advanced signal processing for airport surveillance radars

June 11, 1977
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Conference Paper
Author:
Lincoln Cartledge
…
Published in:
IEEE Electronics and Aerospace Systems Convention, EASCON, 7-9 October 1974.
Topic:
air traffic control
R&D area:
R&D group:

Summary

The inclusion of airport surveillance radars (ASR) in an automated air traffic control system, such as the ARTS-III, has been limited by the present radar's capability to automatically reject ground clutter, weather clutter and angels while still maintaining good detectability on all aircraft within their coverage patterns. Analytical and experimental studies have been performed which indicate that new techniques can significantly enhance the automated capability of these radars. A special-purpose, hard-wired, digital signal processor has been designed, built and tested which provides near-optimum target detection over the entire ASR coverage out to 48 nmi. The processor which coherently integrates eight pulses has both a fine grained clutter map for optimal thresholding in high ground clutter environments and a mean-level thresholding scheme for filtering those Doppler cells which contain heavy precipitation. Because of the processor's ability to detect targets in a high ground clutter environment, the ASR's will be able to operate their antennas at lower elevation angles and, thus, have better coverage of low flying aircraft near the terminal. The processor is initially being tested on a highly modified, coherent S-band, FPR-18 radar. The stability of the klystron transmitter was improved so that it would not limit system performance and a new, wide dynamic range, linear receiver was provided.
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Summary

The inclusion of airport surveillance radars (ASR) in an automated air traffic control system, such as the ARTS-III, has been limited by the present radar's capability to automatically reject ground clutter, weather clutter and angels while still maintaining good detectability on all aircraft within their coverage patterns. Analytical and experimental...

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Advanced signal processing for airport surveillance radars

Automatic Reporting of Height (AROH) design and trade-off studies

November 1, 1976
  |
Technical Report
Author:
Lincoln Cartledge
…
Published in:
MIT Lincoln Laboratory Report TN-1976-42
Topic:
air traffic control
R&D area:
R&D group:

Summary

Application of MTD signal processing and state-of-the-art data processing can result in a completely automatic nodding beam height finder. The resulting savings in manpower are significant. Calculations show that such a system should have good sensitivity and adequate rejection of ground and weather clutter. Modification of an FPS-6 radar for this purpose is discussed.
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Summary

Application of MTD signal processing and state-of-the-art data processing can result in a completely automatic nodding beam height finder. The resulting savings in manpower are significant. Calculations show that such a system should have good sensitivity and adequate rejection of ground and weather clutter. Modification of an FPS-6 radar for...

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Automatic Reporting of Height (AROH) design and trade-off studies

PALM - a system for precise aircraft location

May 16, 1976
  |
Journal Article
Author:
Irvin G. Stiglitz
…
Published in:
J. of the Institute of Navigation, Vol. 23, No. 3, Fall 1976, pp. 257-261.
Topic:
air traffic control
R&D area:
R&D group:

Summary

The Precision Altitude and Landing Monitor (PALM) is intended to provide accurate stand-alone three-dimensional position data for aircraft equipped with standard beacon transponders using ground equipment designed for low life cycle cost. The PALM program, to the present time, has focused on an experimental evaluation of the accuracy of elevation measurements. The results of these measurements have successfully validated the theoretical prediction of a 1-mrad (0.06 degree) elevation accuracy at low elevation angles. The key features in the PALM design include (1) No new avionics required, i.e., it uses standard aircraft transponder. IFPALM is used as the data base for certain ground-to-air messages, a standard VHF or DABS data link could be employed. (2) High accuracy position data, i.e., a 1-mrad rms error in elevation and in azimuth at low elevation angles. (3) Broad airspace coverage, e.g., 40 degrees in elevation, 120 degrees in azimuth (expandable to 360 degrees), and several tens of miles in range. (4) Low life cycle equipment cost, i.e., it incorporates a fixed passive receiving antenna array and a minicomputer to perform the signal processing necessary for interference rejection.
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Summary

The Precision Altitude and Landing Monitor (PALM) is intended to provide accurate stand-alone three-dimensional position data for aircraft equipped with standard beacon transponders using ground equipment designed for low life cycle cost. The PALM program, to the present time, has focused on an experimental evaluation of the accuracy of elevation...

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PALM - a system for precise aircraft location

The Airborne Measurement Facility (AMF) system description

March 25, 1976
  |
Project Report
Author:
George V. Colby
Published in:
MIT Lincoln Laboratory Report ATC-60
Topic:
air traffic control
R&D area:
R&D group:

Summary

The Airborne Measurement Facility (AMF) is a data collection and conversion system that provides a means for obtaining recorded data representing pulsed electromagnetic signals received on one of the two ATC radar beacon frequency bands that is selected for a given data collecting mission. The facility consists of two subsystems: (1) an airborne subsystem which collects and records data during flight, and (2) a ground playback facility which processes the data and transcribes it onto computer-compatible tape.
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Summary

The Airborne Measurement Facility (AMF) is a data collection and conversion system that provides a means for obtaining recorded data representing pulsed electromagnetic signals received on one of the two ATC radar beacon frequency bands that is selected for a given data collecting mission. The facility consists of two subsystems...

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The Airborne Measurement Facility (AMF) system description

IPC design validation and flight testing - interim results

March 16, 1976
  |
Project Report
Author:
John W. Andrews
…
Published in:
MIT Lincoln Laboratory Report ATC-57
Topic:
air traffic control
R&D area:
R&D group:

Summary

Intermittent Positive Control, an automated aircraft collision avoidance system requiring the participation of the aircraft pilots involved, is being evaluated in a series of live flight tests. This document provides an interim summary of the results obtained in these flight tests. Results are given for IPC algorithm design evaluation flights (34) and for pilot interaction evaluation flights (14) flown from Hanscom Field, Bedford, Massachusetts between February and October, 1975.
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Summary

Intermittent Positive Control, an automated aircraft collision avoidance system requiring the participation of the aircraft pilots involved, is being evaluated in a series of live flight tests. This document provides an interim summary of the results obtained in these flight tests. Results are given for IPC algorithm design evaluation flights...

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IPC design validation and flight testing - interim results

Optimum elevation angle estimation in the presence of ground reflection multipath

February 9, 1976
  |
Technical Report
Author:
Robert J. McAulay
Published in:
MIT Lincoln Laboratory Report TN-1976-11
Topic:
air traffic control
R&D area:
R&D group:

Summary

An optimal trade-off between the width of the subarray aperture and the width of the interferometer base line is performed that achieves a specified elevation angle estimation error while minimizing the overall height of the interferometer configuration. Statistical decision theory is used to analyze and design a separate sensor for resolving the interferometer ambiguities. For coverage over 2.5 to 40 in elevation and +/-60 in azimuth, two 7-wavelength subarrays separated by 8 wavelengths are sufficient for 1-mrad elevation-angle errors. A 4-element nonuniformly spaced array of dipole antennas mounted on tri-plane reflectors renders the probability of an ambiguity error less than 0.004.
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Summary

An optimal trade-off between the width of the subarray aperture and the width of the interferometer base line is performed that achieves a specified elevation angle estimation error while minimizing the overall height of the interferometer configuration. Statistical decision theory is used to analyze and design a separate sensor for...

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Optimum elevation angle estimation in the presence of ground reflection multipath
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