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The AMPS computer system: design and operation

September 9, 1982
  |
Project Report
Author:
Jeffrey L. Gertz
…
Published in:
MIT Lincoln Laboratory Report ATC-110
Topic:
surveillance
R&D area:
R&D group:

Summary

The Lincoln Laboratory Air Traffic Control Radar Beacon System (ATCRBS) Monopulse Processing System (AMPS) is a mobile, stand-alone, ATCRBS surveillance sensor for processing and disseminating target reports from transponder-equipped aircraft. AMPS is essentially the ATCRBS portion of the Mode Select Beacon System (Mode S), a system designed to be an evolutionary replacement for the present third generation ATCRBS. AMPS utilizes several new features introduced by the Mode S sensor concept. In particular, the use of monopulse angle estimation permits more accurate aircraft azimuth estimation with fewer replies per scan, and improved decoding (identification) performance when garble is present. This report provides a description of the details and philosophy of the AMPS computer system implementation and operation. In particular, specific and detailed descriptions of the interrelations between AMPS's several subsystems and subtasks are provided as well as a guide on how to run them.
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Summary

The Lincoln Laboratory Air Traffic Control Radar Beacon System (ATCRBS) Monopulse Processing System (AMPS) is a mobile, stand-alone, ATCRBS surveillance sensor for processing and disseminating target reports from transponder-equipped aircraft. AMPS is essentially the ATCRBS portion of the Mode Select Beacon System (Mode S), a system designed to be an...

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The AMPS computer system: design and operation

En route weather data extraction from ATC radar systems

March 11, 1982
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Project Report
Author:
David Karp
Published in:
MIT Lincoln Laboratory Report ATC-113
Topic:
radar
R&D area:
R&D group:

Summary

This report describes the results of phase I of the En Route Radar Weather Program. The objective of this effort was to develop techniques for generating accurate en route weather reflectivity estimates in the presence of ground clutter. A candidate weather data extraction processor is proposed for use with either the ASR-MTD or ARSR-MTD radar systems. Principal features of the candidate processor include: (1) an antenna port (to permit use of an appropriate polarization), front end (with R^-2 STC) and quadrature video sampling subsystem which are separate from that used for aircraft surveillance. (2) use of a ground clutter map to select the form of clutter rejection to be used in each individual range-azimuth cell to estimate various weather reflectivity levels, and (3) spatial /temporal smoothing of the cell reflectivity estimates. The key elements of the suggested signal processing techniques were evaluated using data from MTD tests in Bedford, VA, Burlington, VT, and Atlantic City, NJ; however, the full system has not as yet received design validation/refinement and operational evaluation by ATC controllers. In particular, methods for identifying second trip weather echos should be addressed in the full system validation program.
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Summary

This report describes the results of phase I of the En Route Radar Weather Program. The objective of this effort was to develop techniques for generating accurate en route weather reflectivity estimates in the presence of ground clutter. A candidate weather data extraction processor is proposed for use with either...

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En route weather data extraction from ATC radar systems

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

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 Transportable Measurements Facility (TMF) system description

May 23, 1980
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Project Report
Author:
Raymond R. LaFrey
…
Published in:
MIT Lincoln Laboratory Report ATC-91
Topic:
antennas
R&D area:
R&D group:

Summary

This report describes the MIT Lincoln Laboratory Transportable Measurements Facility (TMF), a special purpose beacon interrogator patterned after the Discrete Address Beacon Sensor. This van-mounted experimental beacon system includes all ATCRBS/DABS reply processing and monopulse processing, but not other DABS processing. It was developed to collect data at various locations in the United States so that candidate DABS sensor antenna and processing could be evaluated in a real environment. The TMF has been installed and operated at: Logan Airport (Boston), Deer Island, MA (near Logan), Washington National Airport (DCA), Philadelphia Int. Airport (PHL), Clementon, NJ (near Philadelphia), Los Angeles Int. Airport (LAX), Brea, CA (25 miles east of LAX), Salt Lake City, UT (SLC), Layton, UT (near Salt Lake City), Las Vegas Airport (LAS), and Green Airport (Warwick, RI).
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Summary

This report describes the MIT Lincoln Laboratory Transportable Measurements Facility (TMF), a special purpose beacon interrogator patterned after the Discrete Address Beacon Sensor. This van-mounted experimental beacon system includes all ATCRBS/DABS reply processing and monopulse processing, but not other DABS processing. It was developed to collect data at various locations...

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The Transportable Measurements Facility (TMF) system description

DABS: Functional Description (Revision A)

April 11, 1980
  |
Project Report
Author:
Vincent A. Orlando
…
Published in:
MIT Lincoln Laboratory Report ATC-42,A
Topic:
surveillance
R&D area:
R&D group:

Summary

This document provides a functional description of the Discrete Address Beacon System (DABS), a combined secondary surveillance radar (beacon) and ground-air-ground data link system capable of providing the aircraft surveillance and communications necessary to support ATC automation in future traffic environments. DABS is capable of common-channel interoperation with the current ATC beacon system, and may be implemented at low user cost over an extended ATCRBS-to-DABS transition period. In supporting ATC automation, DABS will provide the surveillance and communication performance required by the Automatic Traffic Advisory and Resolution Service (ATARS), the reliable communications needed to support data link services, and the capability of operating with a terminal or enroute, radar digitizer-equipped, ATC surveillance radar. The material contained in this document updates and expands the information presented in "DABS: A System Description", FAA-RD-74-189, November 1974.
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Summary

This document provides a functional description of the Discrete Address Beacon System (DABS), a combined secondary surveillance radar (beacon) and ground-air-ground data link system capable of providing the aircraft surveillance and communications necessary to support ATC automation in future traffic environments. DABS is capable of common-channel interoperation with the current...

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DABS: Functional Description (Revision A)
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