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Moving Target Detector (Mod II) summary report

November 3, 1981
  |
Project Report
Author:
David Karp
…
Published in:
MIT Lincoln Laboratory Report ATC-95
Topic:
surveillance
R&D area:
R&D group:

Summary

Under FAA sponsorship, MIT/Lincoln Laboratory has developed a second generation, field operable Moving Target Detection System (MTD-II) which has been tested at operational FAA terminal and enroute radar sites, and serves as the basis for the ASR-9 MTD technical performance specifications. This summary report covers the period October, 1976 through September, 1979 in which design, development, field testing and system performance evaluation were carried out. Report No. FAA-RD-76-190, ATC-69, "Description and Performance Evaluation of the Moving Target Detector" dated 8 March 1977, serves as the technical foundation of this work. MTD-processing design modifications were effected to handle conditions of excessive ground clutter and moving ground traffic. The rationale for the modified algorithms is provided, and measured performance characteristics at several FAA field sites are discussed.
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Summary

Under FAA sponsorship, MIT/Lincoln Laboratory has developed a second generation, field operable Moving Target Detection System (MTD-II) which has been tested at operational FAA terminal and enroute radar sites, and serves as the basis for the ASR-9 MTD technical performance specifications. This summary report covers the period October, 1976 through...

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Moving Target Detector (Mod II) summary report

ATCRBS uplink environment measurements near Jacksonville, Florida

September 25, 1981
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Project Report
Author:
Ferenc Nagy Jr
Published in:
MIT Lincoln Laboratory Report ATC-94
Topic:
surveillance
R&D area:
R&D group:

Summary

Airborne measurements of the Air Traffic Control Radar Beacon System (ATCRBS) 1030 MHz uplink environment are described. Measurements were made using the AMF, a special purpose airborne sensor-recorder, during a 23 May 1979 flight in the greater Jacksonville, Florida area. The 2-way flight covered the 450 nm coastline between Fayetteville (NC) and Vero Beach (FL) first at 10,000 then at 25,000 feet. Data recorded at 61 locations have been analyzed to plot combined pulse, interrogation and suppression rates for all locations and individual rates, received powers and angles for 37 locations. Fifty-nine ground interrogators were detected and a list included serves as an all-interrogator/all-location (59 x 37) visibility matrix. PRI/PRF distributions of interrogations received are shown at three selected measurement locations. A pulse-by-pulse plot of over 50 Mode 4 interrogations shows their effect on a typical transponder. A "worst" location is examined for peak instantaneous interrogation rates capable of causing transponder reply-rate limiting (RRL), desensitization and track loss. Durations and periods of recurrence of "synchronous jamming" for 23 near-equal scan periods are computed. Probabilities of multiple mainbeam coincidences ("multi-PRF jamming") are also calculated. Airborne (AMF) and ground based (FAA En-Route) coverages are compared, and reported operational problems (target splits, lost tracks, poor coverage) are addressed.
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Summary

Airborne measurements of the Air Traffic Control Radar Beacon System (ATCRBS) 1030 MHz uplink environment are described. Measurements were made using the AMF, a special purpose airborne sensor-recorder, during a 23 May 1979 flight in the greater Jacksonville, Florida area. The 2-way flight covered the 450 nm coastline between Fayetteville...

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ATCRBS uplink environment measurements near Jacksonville, Florida

Coordinated radar and aircraft observations of turbulence

May 26, 1981
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Project Report
Author:
Melvin Labitt
Published in:
MIT Lincoln Laboratory Report ATC-108
Topic:
weather
R&D area:
R&D group:

Summary

Interim results of a program to measure and correlate radar- and aircraft-sensed turbulence in rainstorms are presented. The dissipation factor of a turbulence air mass can be measured by an aircraft and a weather radar. Comparisons are made between precipitation reflectivity and spectral width measurements as indicators of turbulence. The instrumentation and data processing procedures are described. Examples of turbulence observations made with a storm-penetrating aircraft and the weather radar are given. The relationship between the radar observations and the physical properties of the turbulence atmosphere are derived. The relationship of radar spectral width (variance) to turbulence intensity is discussed.
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Summary

Interim results of a program to measure and correlate radar- and aircraft-sensed turbulence in rainstorms are presented. The dissipation factor of a turbulence air mass can be measured by an aircraft and a weather radar. Comparisons are made between precipitation reflectivity and spectral width measurements as indicators of turbulence. The...

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Coordinated radar and aircraft observations of turbulence

An improved technique for altitude tracking of aircraft

March 25, 1981
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Project Report
Author:
John W. Andrews
Published in:
MIT Lincoln Laboratory Report ATC-105
Topic:
surveillance
R&D area:
R&D group:

Summary

When simple linear recursive tracking techniques are applied to quantized altitude reports, certain errors in estimation of altitude and altitude rate can be attributed to the response of the tracker to transitions between quantization levels. These errors can be reduced by use of an estimation technique which explicitly recognizes the quantized nature of the inputs. Smoothing of the level occupancy time (i.e., the time spent at each quantization level) can be used to control the response to redundant samples taken at the same quantization level. Further improvement is achieved by consistency tests which use particular properties of quantized data to detect changes in rate. This document presents a theoretical analysis of tracker repsonse to quantized inputs. A tracking algorithm is synthesized using these techniques and simulation results using various altitude profiles are presented.
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Summary

When simple linear recursive tracking techniques are applied to quantized altitude reports, certain errors in estimation of altitude and altitude rate can be attributed to the response of the tracker to transitions between quantization levels. These errors can be reduced by use of an estimation technique which explicitly recognizes the...

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An improved technique for altitude tracking of aircraft

Radar Beacon Transponder (RBX) installation and siting criteria

March 13, 1981
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Project Report
Author:
Ronald G. Sandholm
Published in:
MIT Lincoln Laboratory Report ATC-106
Topic:
surveillance
R&D area:
R&D group:

Summary

The Radar BEacon Transponder (RBX) is a ground-based facility used in conjunction with other elements of the Active Beacon Collision Avoidance System (BCAS) to control the threat detection sensitivity level of BCAS aircraft and to convey displayed Resolution Advisories from the BCAS aircraft to the local ATC terminal facility. This paper describes the mechanisms of specular multipath reflection and signal shadowing and discussed their impact on the RBX link power budget. Criteria for choice of RBX antenna height and location are presented.
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Summary

The Radar BEacon Transponder (RBX) is a ground-based facility used in conjunction with other elements of the Active Beacon Collision Avoidance System (BCAS) to control the threat detection sensitivity level of BCAS aircraft and to convey displayed Resolution Advisories from the BCAS aircraft to the local ATC terminal facility. This...

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Radar Beacon Transponder (RBX) installation and siting criteria

Radar Beacon Transponder (RBX) functional description

February 18, 1981
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Project Report
Author:
Ronald G. Sandholm
Published in:
MIT Lincoln Laboratory Report ATC-104
Topic:
surveillance
R&D area:
R&D group:

Summary

The Radar Beacon Transponder (RBX) is a ground-based transponder used to control the threat-detection sensitivity level of BCAS aircraft operating in high density terminal airspace. THe RBX is also used to deliver displayed resolution advisories from BCAS to the ATC facility. The normal DABS interrogation waveforms and message formats are used for communication between the RBX and BCAS aircraft. The appropriate BCAS sensitivity level is selected by comparing the BCAS aircraft position with an internally stored sensitivity level map of the surrounding airspace volume. This document provides a functional description of the RBX and shows that reliable performance is achievable in the presence of interference from ATCRBS and BCAS air-to-air interrogations.
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Summary

The Radar Beacon Transponder (RBX) is a ground-based transponder used to control the threat-detection sensitivity level of BCAS aircraft operating in high density terminal airspace. THe RBX is also used to deliver displayed resolution advisories from BCAS to the ATC facility. The normal DABS interrogation waveforms and message formats are...

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Radar Beacon Transponder (RBX) functional description

Electronic flight rules: an alternative separation assurance concept

December 31, 1980
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Project Report
Author:
John W. Andrews
…
Published in:
MIT Lincoln Laboratory Report ATC-93
Topic:
air traffic control
R&D area:
R&D group:

Summary

This report presents results of a study of alternative concepts for tactically separating aircraft in low altitude en route airspace. It describes a concept designated Electronic Flight Rules (EFR) which allows aircraft to fly under instrument meteorological conditions in a manner that retains most of the freedom and flexibility of VFR flight. Feasibility considerations, potential benefits, applicable technologies, and alternative system configurations are evaluated.
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Summary

This report presents results of a study of alternative concepts for tactically separating aircraft in low altitude en route airspace. It describes a concept designated Electronic Flight Rules (EFR) which allows aircraft to fly under instrument meteorological conditions in a manner that retains most of the freedom and flexibility of...

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Electronic flight rules: an alternative separation assurance concept

Active Beacon Collision Avoidance System (BCAS) functional overview

December 17, 1980
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Project Report
Author:
Jerry D. Welch
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Published in:
MIT Lincoln Laboratory Report ATC-102
Topic:
collision avoidance
R&D area:
R&D group:

Summary

The Active Beacon Collision Avoidance System (BCAS) is a beacon-based airborne collision avoidance system that provides for cooperative threat resolution between BCAS and conflicting aircraft and coordination with the ground ATC control function through the DABS data link. All beacon-equipped aircraft in the vicinity of the BCAS are detected. ATCRBS-equipped aircraft are interrogated using a special Mode C interrogation. DABS aircraft are initially detected passively. Those aircraft that represent a possible threat are discretely interrogated to maintain a range/altitude track. This document provides a functional overview of BCAS including operational features, a description of the avionics package, and examples of surveillance data obtained with experimental BCAS equipment. The results show that reliable surveillance performance is achieved in low and medium density airspace.
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Summary

The Active Beacon Collision Avoidance System (BCAS) is a beacon-based airborne collision avoidance system that provides for cooperative threat resolution between BCAS and conflicting aircraft and coordination with the ground ATC control function through the DABS data link. All beacon-equipped aircraft in the vicinity of the BCAS are detected. ATCRBS-equipped...

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Active Beacon Collision Avoidance System (BCAS) functional overview

Active BCAS: design and validation of the surveillance subsystem

December 17, 1980
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Project Report
Author:
William H. Harman III
…
Published in:
MIT Lincoln Laboratory Report ATC-103
Topic:
collision avoidance
R&D area:
R&D group:

Summary

Lincoln Laboratory, under FAA sponsorship, is developing an Active Beacon Collision Avoidance System (BCAS), concentrating primarily on the air-to-air surveillance subsystem. The surveillance functions required are to detect the presence of nearby aircraft (whether they are equipped with ATCRBS transponders or DABS transponders), and then generate a surveillance track on each aircraft, issuing range and altitude reports once per second. The development effort consisted of airborne measurements complemented by simulation studies and analyses. The basic effects of ground-bounce multipath, interference, and power fading were assessed by air-to-air measurements. In other measurements, the BCAS interrogation and reply signal formats were transmitted between aircraft, and the results recorded for later playback and computer processing using the BCAS surveillance algorithms. This is a flexible means of experimentation which allows many of the design parameters to be changed as the effects are noted. In the most recent phase of the program, Lincoln designed and built realtime BCAS Experimental Units (BE Us), flight tested them, and then delivered them to the FAA for more extensive flight testing. In one of these flight tests, a BEU-equipped Boeing 727 flew to New York, Atlanta, and other major terminal areas in the eastern U.S. An analysis of BEU performance during this "Eastern Tour" is given in this report.
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Summary

Lincoln Laboratory, under FAA sponsorship, is developing an Active Beacon Collision Avoidance System (BCAS), concentrating primarily on the air-to-air surveillance subsystem. The surveillance functions required are to detect the presence of nearby aircraft (whether they are equipped with ATCRBS transponders or DABS transponders), and then generate a surveillance track on...

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Active BCAS: design and validation of the surveillance subsystem

The DABS data link airborne intelligent display operator's manual

September 1, 1980
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Project Report
Author:
James C. Anderson
…
Published in:
MIT Lincoln Laboratory Report ATC-100
Topic:
air traffic control
R&D area:
R&D group:

Summary

The Federal Aviation Administration is currently evaluating the Discrete Address Beacon System (DABS) which will provide increased air traffic safety in current and future air traffic conditions. In addition to improved surveillance accuracy and reliability, DABS provides a two-way data link between the DABS sensor and all DABS transponder equipped aircraft in view. A DABS data link avionics system, called the Airborne Intelligent Display (AID), was developed by M.I.T. Lincoln Laboratory for the purpose of evaluating and demonstrating initial and future data link applications. The microprocessor-based AID system communicates with the DABS ground sensor through the DABS transponder onboard the aircraft. Data link information included in uplink interrogations to the transponder is decoded in the airborne microprocessor and then made available to the pilot on a high visibility cathode ray tube display. The purpose of this report is to describe the operation and use of the AID.
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Summary

The Federal Aviation Administration is currently evaluating the Discrete Address Beacon System (DABS) which will provide increased air traffic safety in current and future air traffic conditions. In addition to improved surveillance accuracy and reliability, DABS provides a two-way data link between the DABS sensor and all DABS transponder equipped...

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The DABS data link airborne intelligent display operator's manual
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