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Applying artificial intelligence techniques to air traffic control automation

January 1, 1989
  |
Journal Article
Author:
David A. Spencer
Published in:
Lincoln Laboratory Journal, Vol. 2, No. 3, Fall 1989, pp. 537-554.
Topic:
air traffic control
R&D area:
R&D group:

Summary

We have developed a computer program that automates rudimentary air traffic control (ATC) planning and decision-making functions. The ability to plan, make decisions, and act on them makes this experimental program qualitatively different from the more clerical ATC software currently in use. Encouraging results were obtained from tests involving simple scenarios used to train air traffic controllers.
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Summary

We have developed a computer program that automates rudimentary air traffic control (ATC) planning and decision-making functions. The ability to plan, make decisions, and act on them makes this experimental program qualitatively different from the more clerical ATC software currently in use. Encouraging results were obtained from tests involving simple...

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Applying artificial intelligence techniques to air traffic control automation

Experimental examination of the benefits of improved terminal air traffic control planning

January 1, 1989
  |
Journal Article
Author:
David A. Spencer
…
Published in:
Lincoln Laboratory Journal, Vol. 2, No. 3, Fall 1989, pp. 527-536.
Topic:
air traffic control
R&D area:
R&D group:

Summary

Airport capacity can be improved significantly-by precisely controlling the sequence and timing of traffic flow-even when airspace usage and procedures remain fixed. In a preliminary experiment, a plan for such sequencing and timing was applied in a simulation to a 70-min traffic sample observed at Boston's Logan Airport, and the result was a 13% increase in terminal throughput. A total of 2.2 aircraft flight hours were saved. Delays imposed upon arriving traffic in the simulation were much more equitably distributed than in the actual traffic sample. An even greater improvement may be possible if controllers are able to space aircraft more precisely on final approach than was achieved in the simulation. If the plan had been followed precisely, the throughput increase would have been 23%.
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Summary

Airport capacity can be improved significantly-by precisely controlling the sequence and timing of traffic flow-even when airspace usage and procedures remain fixed. In a preliminary experiment, a plan for such sequencing and timing was applied in a simulation to a 70-min traffic sample observed at Boston's Logan Airport, and the...

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Experimental examination of the benefits of improved terminal air traffic control planning

Electrical characteristics of microburst-producing storms in Denver

January 1, 1989
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Conference Paper
Author:
Earle R. Williams
…
Published in:
Proc. 24th Conf. on Radar Meteorology, 27-31 March 1989, pp. 89-92.
Topic:
aviation weather
R&D area:
R&D group:

Summary

Coordinated Doppler radar and electrical measurements of thunderstorm microbursts were initiated by Lincoln Laboratory and the MIT Weather Radar group in Huntsville, AL in 1987. These measurements were intended to identify electrical precursors to aviation hazards at ground level and to study the relationship between the state of cloud convective development and the prevalent lightning type. The results of the Huntsville Study (Williams and Orville, 1988; Williamd et al., 1988) showed pronounced peaks in intracloud lightning activity and radar reflectivity above the melting level 5-10 minutes prior to maximum outflow velocities at the surface. A similar behavior has been reported by Goodman et al. (1988) for a thunderstorm observed in COHMEX in the same region. These observations support a prominent role for ice, both in promoting the intracloud lightning aloft and in subsequently driving the outflow by virtue of the melting process. All Huntsville cases studied were 'wet' microbursts with maximum low level reflectivity factors greater than 50 dBZ. The parent storms were deep (H>11km) and electrically active (flash rate greater than or equal to 1min^-1). Recent microburst studies in Denver (Hjelmfelt, 1987); Biron and isaminger, 1989) have identified, in addition to a majority of 'wet' microbursts, substantial numbers of dry microburst-producing storms (Z<10^3 mm^6/m^3) with elevated cloud bases and modest radar cloud tops. The present studies were aimed at determining to what extent the electrical manifestations observed in Huntsville were prevalent in Denver. This paper presents some preliminary results for the Denver measurements from the summer of 1988.
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Summary

Coordinated Doppler radar and electrical measurements of thunderstorm microbursts were initiated by Lincoln Laboratory and the MIT Weather Radar group in Huntsville, AL in 1987. These measurements were intended to identify electrical precursors to aviation hazards at ground level and to study the relationship between the state of cloud convective...

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Electrical characteristics of microburst-producing storms in Denver

Multisensor surveillance for improved aircraft tracking

January 1, 1989
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Journal Article
Author:
Jeffrey L. Gertz
Published in:
Lincoln Laboratory Journal, Vol. 2, No. 3, Fall 1989, pp. 381-396.
Topic:
aircraft
R&D area:
R&D group:

Summary

Cross-range measurements of aircraft travelling at distances of 50 to 200 miles include significant errors. Therefore, heading estimates for medium-to-long-range aircraft are not sufficiently accurate to be useful in conflict-detection predictions. Accurate crossrange measurements can be made-by using two or more sensors to measure aircraft position-but such measurements must compensate for the effects of system biases and aircraft turns. A set of algorithms has been developed that are resistant to system biases, that detect turns, and that track successfully through both biases and turns. These algorithms can be incorporated into a complete multisensor system, with good intersensor correlation of aircraft tracks and no added delays to the air traffic control processing chain.
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Summary

Cross-range measurements of aircraft travelling at distances of 50 to 200 miles include significant errors. Therefore, heading estimates for medium-to-long-range aircraft are not sufficiently accurate to be useful in conflict-detection predictions. Accurate crossrange measurements can be made-by using two or more sensors to measure aircraft position-but such measurements must compensate...

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Multisensor surveillance for improved aircraft tracking

Parallel runway monitor

January 1, 1989
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Journal Article
Author:
Raymond R. LaFrey
Published in:
Lincoln Laboratory Journal, Vol. 2, No. 3, Fall 1989, pp. 411-436.
Topic:
air traffic control
R&D area:
R&D group:

Summary

The availability of simultaneous independent approaches to parallel runways significantly enhances airport capacity. Current FAA procedures permit independent approaches in instrument meteorological conditions (IMC) when the parallel runways are spaced at least 4,300 ft apart. Arriving aircraft must be dependently sequenced at airports that have parallel runways separated by less than 4,300 ft, a procedure that reduces the arrival rate by as much as 250h. The need for greater airport capacity has led to intense interest in new technologies that can support independent parallel IMC approaches to runways spaced as close as 3,000 ft. This interest resulted in several FAA initiatives, including a Lincoln Laboratory program to evaluate the applicability of Mode-S secondary surveillance radars for monitoring parallel runway approaches. This paper describes the development and field activities of this program.
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Summary

The availability of simultaneous independent approaches to parallel runways significantly enhances airport capacity. Current FAA procedures permit independent approaches in instrument meteorological conditions (IMC) when the parallel runways are spaced at least 4,300 ft apart. Arriving aircraft must be dependently sequenced at airports that have parallel runways separated by less...

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Parallel runway monitor

TCAS: a system for preventing midair collisions

January 1, 1989
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Journal Article
Author:
William H. Harman III
Published in:
Lincoln Laboratory Journal, Vol. 2, No. 3, Fall 1989, pp. 437-458.
Topic:
air traffic control
R&D area:
R&D group:

Summary

To reduce the possibility of midair collisions, the Federal Aviation Administration has developed the Traffic Alert and Collision Avoidance System, or TCAS. This airborne system senses the presence of nearby aircraft by interrogating the transponders carried by these aircraft. When TCAS senses that a nearby aircraft is a possible collision threat, TCAS issues a traffic advisory to the pilot, indicating the presence and location of the other aircraft. If the encounter becomes hazardous, TCAS issues a maneuver advisory.
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Summary

To reduce the possibility of midair collisions, the Federal Aviation Administration has developed the Traffic Alert and Collision Avoidance System, or TCAS. This airborne system senses the presence of nearby aircraft by interrogating the transponders carried by these aircraft. When TCAS senses that a nearby aircraft is a possible collision...

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TCAS: a system for preventing midair collisions

Using aircraft radar tracks to estimate winds aloft

January 1, 1989
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Journal Article
Author:
Walter M. Hollister
…
Published in:
Lincoln Laboratory Journal, Vol. 2, No. 3, Fall 1989, pp. 555-565.
Topic:
aviation weather
R&D area:
R&D group:

Summary

In air traffic control, the wind is a critical factor because it affects, among other important variables, the amount of time an aircraft will take to reach its destination. The authors have developed a method for estimating winds aloft in which the radar tracks of aircraft are used; i.e., data beyond what are already available to terminal air traffic control are not required. The method, which has been implemented at Lincoln Laboratory, gives a useful estimate of wind fields.
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Summary

In air traffic control, the wind is a critical factor because it affects, among other important variables, the amount of time an aircraft will take to reach its destination. The authors have developed a method for estimating winds aloft in which the radar tracks of aircraft are used; i.e., data...

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Using aircraft radar tracks to estimate winds aloft

The mode S beacon radar system

January 1, 1989
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Journal Article
Author:
Vincent A. Orlando
Published in:
Lincoln Laboratory Journal, Vol. 2, No. 3, Fall 1989, pp. 345-362.
Topic:
air traffic control
R&D area:
R&D group:

Summary

Air traffic controllers rely on primary and secondary radars to locate and identify aircraft. Secondary, or beacon, radars require aircraft to carry devices called transponders that enhance surveillance echoes and provide data links. Airports currently use a secondary-radar system known as the Air Traffic Control Radar Beacon System (ATCRBS). However, ATCRBS has limitations in dense-traffic conditions, and the system's air-to-ground data link is limited. In response to these shortcomings, Lincoln Laboratory has developed the Mode Select Beacon System (referred to as Mode S), a next-generation system that extensive laboratory and field testing has validated. In addition to significant surveillance improvements, Mode S provides the general-purpose ground-air-ground data link necessary to support the future automation of air traffic control (ATC). The Federal Aviation Administration (FAA) is currently installing the system with initial operation scheduled for 1991.
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Summary

Air traffic controllers rely on primary and secondary radars to locate and identify aircraft. Secondary, or beacon, radars require aircraft to carry devices called transponders that enhance surveillance echoes and provide data links. Airports currently use a secondary-radar system known as the Air Traffic Control Radar Beacon System (ATCRBS). However...

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The mode S beacon radar system

Wind shear detection with pencil-beam radars

January 1, 1989
  |
Journal Article
Author:
Mark W. Merritt
…
Published in:
Lincoln Laboratory Journal, Vol. 2, No. 3, Fall 1989, pp. 483-510.
Topic:
aviation weather
R&D area:
R&D group:

Summary

Abrupt changes in the winds near the ground pose serious hazards to aircraft during approach or departure operations. Doppler weather radars can measure regions of winds and precipitation around airports, and automatically provide air traffic controllers and pilots with important warnings of hazardous weather events. Lincoln Laboratory, as one of several organizations under contract to the Federal Aviation Administration, has been instrumental in the design and development of radar systems and automated weather-hazard recognition techniques for this application. The Terminal Doppler Weather Radar (TDWR) system uses automatic computer algorithms to ident* hazardous weather signatures. TDWR detects and warns aviation users about low-altitude wind shear hazards caused by microbursts and gust fronts. It also provides advance warning of the arrival of wind shifts at the airport complex. Extensive weather radar observations, obtained from a Lincoln-built transportable testbed radar system operated at several sites, have validated the TDWR system. As a result, the Federal Aviation Administration has issued a procurement contract for the installation of 47 TDWR radar systems around the country.
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Summary

Abrupt changes in the winds near the ground pose serious hazards to aircraft during approach or departure operations. Doppler weather radars can measure regions of winds and precipitation around airports, and automatically provide air traffic controllers and pilots with important warnings of hazardous weather events. Lincoln Laboratory, as one of...

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Wind shear detection with pencil-beam radars

Wind shear detection with airport surveillance radars

January 1, 1989
  |
Journal Article
Author:
Mark E. Weber
…
Published in:
Lincoln Laboratory Journal, Vol. 2, No. 3, Fall 1989, pp. 511-526.
Topic:
radar
R&D area:
R&D group:

Summary

Airport surveillance radars (ASR) utilize a broad, cosecant-squared elevation beam pattern, rapid azimuthal antenna scanning, and coherent pulsed-Doppler processing to detect and track approaching and departing aircraft. These radars, because of location, rapid scan rate, and direct air traffic control (ATC) data link, can also provide flight controllers with timely information on weather conditions that are hazardous to aircraft. With an added processing channel, an upgraded ASR can automatically detect regions of low-altitude wind shear. This upgrade can provide wind shear warnings at airports where low traffic volume or infrequent thunderstorm activity precludes the deployment of a dedicated Terminal Doppler Weather Radar (TDWR). Field measurements and analysis conducted by Lincoln Laboratory indicate that the principal technical challenges for low-altitude wind shear detection with an ASR-groundclutter suppression, estimation of near-surface radial velocity, and automatic wind shear hazard recognition--can be successfully met for microbursts accompanied by rain at the surface.
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Summary

Airport surveillance radars (ASR) utilize a broad, cosecant-squared elevation beam pattern, rapid azimuthal antenna scanning, and coherent pulsed-Doppler processing to detect and track approaching and departing aircraft. These radars, because of location, rapid scan rate, and direct air traffic control (ATC) data link, can also provide flight controllers with timely...

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Wind shear detection with airport surveillance radars
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