Publications

Refine Results

(Filters Applied) Clear All

Tagged As

Proposed technical characteristics for the Discrete Address Beacon System (DABS)

September 30, 1977
  |
Project Report
Author:
Jerry D. Welch
…
Published in:
MIT Lincoln Laboratory Report ATC-71
Topic:
surveillance
R&D area:
R&D group:

Summary

This report parallels the Proposed U. S. National Aviation Standard for the Discrete Address Beacon System. However, in addition to the material contained in the Proposed Standard this document provides a more detailed performance specification for the DABS transponder including specifications on transponder receiver sensitivity and performance in interference. It includes specifications for a proposed digital datalink interface and defines message and control fields associated with experimental transponder data applications. It also includes guidance material on the performance of an optional transponder antenna diversity scheme.
READ LESS

Summary

This report parallels the Proposed U. S. National Aviation Standard for the Discrete Address Beacon System. However, in addition to the material contained in the Proposed Standard this document provides a more detailed performance specification for the DABS transponder including specifications on transponder receiver sensitivity and performance in interference. It...

READ MORE
Proposed technical characteristics for the Discrete Address Beacon System (DABS)

A hardware implementation of the ATCRBS reply processor used in DABS

September 19, 1977
  |
Project Report
Author:
Richard G. Nelson
…
Published in:
MIT Lincoln Laboratory Report ATC-78
Topic:
surveillance
R&D area:
R&D group:

Summary

A special-purpose digital hardware processor, which implements the ATCRBS Reply Processing algorithms designed for use in the Discrete Address Beacon System (DABS) has been developed and used in two DABS-related programs. This report gives a detailed functional description of this processor as implemented by Lincoln Laboratory. With minor modifications it could serve as the ATCRBS Reply Processor for a Beacon Collision Avoidance System.
READ LESS

Summary

A special-purpose digital hardware processor, which implements the ATCRBS Reply Processing algorithms designed for use in the Discrete Address Beacon System (DABS) has been developed and used in two DABS-related programs. This report gives a detailed functional description of this processor as implemented by Lincoln Laboratory. With minor modifications it...

READ MORE
A hardware implementation of the ATCRBS reply processor used in DABS

DABS coverage

August 16, 1977
  |
Project Report
Author:
Steven I. Krich
Published in:
MIT Lincoln Laboratory Report ATC-75
Topic:
surveillance
R&D area:
R&D group:

Summary

DABS sensors are to be installed at FAA ASR and ARSR sites throughout continental U.S. as a part of the evolutionary upgrading of the third generation ATC Radar Beacon System (ATCRBS). It is therefore important to establish: (1) the degree of 3D coverage which would be provided by such deployment; and (2) a reasonable balance between number of installations, sensor maximum range, and coverage. This paper reports on a coverage study in which DABS coverage within CONUS was projected on a statistical or "percent coverage" basis by purely geometrical considerations. Results are given for CONUS, the eastern half of the U.S., and for the Golden Triangle. Profile coverage ("line-of-sight coverage down to...") is given for the Boston-NYC-Washington corridor.
READ LESS

Summary

DABS sensors are to be installed at FAA ASR and ARSR sites throughout continental U.S. as a part of the evolutionary upgrading of the third generation ATC Radar Beacon System (ATCRBS). It is therefore important to establish: (1) the degree of 3D coverage which would be provided by such deployment...

READ MORE
DABS coverage

Airborne radars for surveillance and weapon delivery

July 15, 1977
  |
Technical Report
Author:
Charles E. Muehe
Published in:
MIT Lincoln Laboratory Report TN-1977-23
Topic:
airborne surveillance
R&D area:
R&D group:

Summary

Airborne radars such as AW ACS capable of large area surveillance of aircraft over both land and sea have become a reality in the past few years. Soon to follow are radars capable of large area surveillance of moving ground traffic. Through their ability to accurately report enemy movement and to target individual enemy ground vehicles, these radars will undoubtedly have a large impact on intelligence gathering, resource allocation, command, control and the damage assessment functions. This report describes relationships and trade-offs fundamental in the design of airborne surveillance radars in various operational roles. It describes radar capabilities which can be achieved using modern technology including array antennas, advanced waveforms and advanced signal processing techniques.
READ LESS

Summary

Airborne radars such as AW ACS capable of large area surveillance of aircraft over both land and sea have become a reality in the past few years. Soon to follow are radars capable of large area surveillance of moving ground traffic. Through their ability to accurately report enemy movement and...

READ MORE
Airborne radars for surveillance and weapon delivery

Description and performance evaluation of the moving target detector

March 8, 1977
  |
Project Report
Author:
Lincoln Cartledge
…
Published in:
MIT Lincoln Laboratory Report ATC-69
Topic:
surveillance
R&D area:
R&D group:

Summary

Under FAA sponsorship, MIT, Lincoln Laboratory has developed new techniques which significantly enhance automated aircraft detection in all forms of clutter. These techniques are embodied in a digital signal processor called the Moving Target Detector (MTD). This processor has been integrated into the ARTS-III system at the National Aviation Facilities Experimental Center, Atlantic City, New Jersey (NAFEC) and has undergone testing during the summer of 1975. This report contains a description of the MTD design and its evaluation tests. A detailed discussion of the significance of the results is also presented. The detection performance of the MTD was excellent in the clear, in rain and ground clutter, and false alarms were under complete control. The MTD processed range and azimuth data was very accurate, and the MTJI did not suffer from track dropouts as did the conventional MTI when the aircraft track became tangential to the radar. Performance was excellent on magnetron as well as klystron-type radars with the exception- of second-time-around clutter cancellation.
READ LESS

Summary

Under FAA sponsorship, MIT, Lincoln Laboratory has developed new techniques which significantly enhance automated aircraft detection in all forms of clutter. These techniques are embodied in a digital signal processor called the Moving Target Detector (MTD). This processor has been integrated into the ARTS-III system at the National Aviation Facilities...

READ MORE
Description and performance evaluation of the moving target detector

DABS monopulse summary

February 4, 1977
  |
Project Report
Author:
David Karp
…
Published in:
MIT Lincoln Laboratory Report ATC-72
Topic:
surveillance
R&D area:
R&D group:

Summary

Improved azimuthal resolution of proximate aircraft necessary to support ATC automation can be achieved by beacon surveillance systems employing monopulse angle estimation techniques described in this report. Included in the report are the results of beacon surveillance monopulse system analyses relating to off-boresight angle estimation using short (1/2 micro sec) pulses: the effects of specular and diffuse multipath signal return; the effects of overlapping ATCRBS fruit replies, and the problems of antenna pattern design. These topics have been studied in detail as part of the Lincoln Laboratory disign of the Discrete Address Beacon System (DABS). This report summarizes analytical results obtained. In general, it has been concluded that the ATC environment does not pose a serious problem to the use of the monopulse concept for beacon system direction finding and that sufficient direction finding accuracy can be obtained using a small number of narrow pulses for each scan.
READ LESS

Summary

Improved azimuthal resolution of proximate aircraft necessary to support ATC automation can be achieved by beacon surveillance systems employing monopulse angle estimation techniques described in this report. Included in the report are the results of beacon surveillance monopulse system analyses relating to off-boresight angle estimation using short (1/2 micro sec)...

READ MORE
DABS monopulse summary

Ionospheric scintillation

February 1, 1977
  |
Journal Article
Author:
Robert K. Crane
Published in:
Proc. of the IEEE, Vol. 65, No. 2, February 1977, pp. 180-199.
Topic:
radar
R&D area:
R&D group:

Summary

Available observations of ionospheric scintillation are analyzed to evaluate the adequacy of existing models used for the interpretation of scintillation data. The theoretical models are reviewed and the frequency and propagation geometry dependences predicted by the models are compared with the observations. The models were used to construct scintillation occurrence distribution functions which show that scintillation phenomena significantly affect the design of transionospheric radar or communication systems operating at frequencies below 1 GHz. Diversity schemes useful for mitigation of scintillation effects are considered. Mention is made of the geophysical processes thought to be responsible for scintillation.
READ LESS

Summary

Available observations of ionospheric scintillation are analyzed to evaluate the adequacy of existing models used for the interpretation of scintillation data. The theoretical models are reviewed and the frequency and propagation geometry dependences predicted by the models are compared with the observations. The models were used to construct scintillation occurrence...

READ MORE
Ionospheric scintillation

ATCRBS mode of DABS

January 31, 1977
  |
Project Report
Author:
Jeffrey L. Gertz
Published in:
MIT Lincoln Laboratory Report ATC-65
Topic:
surveillance
R&D area:
R&D group:

Summary

The Discrete Address Beacon System (DABS) has been designed to be an evolutionary replacement oth the third generation Air Traffic Control Radar Beacon System (ATCRBS). Although the ATCRBS returns processed by DABS will be identical to those currently being employed, the DABS processing system will not merely mimic the present system. Instead, it has been designed to surpass current performance levels even while reducing the number of interrogations transmitted per scan. This will be made possible by utilizing the availability of several new features introduced by the DABS sensor. In particular, the employment of monopulse antenna will permit both more accurate azimuth estimation with fewer replies per scan and improved decoding performance when garble is present. The ATCRBS portion of the DABS sensor has been designed to be a complete, self-contained package that performs all ATCRBS functions required for aircraft surveillance. The major tasks it implements are: 1. Determining the range, azimuth, and code of each received ATCRBS reply 2. Grouping replies from the same aircraft into target reports and discarding fruit replies 3. Identifying all false alarm target reports due to reflections, coincident fruit, splitting, or ringaround 4. Initiating and maintaining a track on all aircraft in the covered airspace The first function has been implemented in hardware while the remaining ones are performed in software. This report will discuss in detail only the software subsystems. The ATCRBS system described in this report has been implemented in the ATCRBS Monopulse Processing System (AMPS) built at Lincoln Laboratory. Although the AMPS design is based upon the specifications contained in the DABS Engineering Requirements (ER), there are two major differences between AMPS and the ER system. First, the design described here is for a standalone ATCRBS system; no capabilities are built in to send, receive, or employ information from other sensors, and no formal interfaces to other ATC functions are defined. Second, this system was not intended to be a production prototype, so no reliability features have been included.
READ LESS

Summary

The Discrete Address Beacon System (DABS) has been designed to be an evolutionary replacement oth the third generation Air Traffic Control Radar Beacon System (ATCRBS). Although the ATCRBS returns processed by DABS will be identical to those currently being employed, the DABS processing system will not merely mimic the present...

READ MORE
ATCRBS mode of DABS

The PMP, a programmable radar signal processor

October 7, 1976
  |
Conference Paper
Author:
Bruce G. Laird
…
Published in:
Monthly Mtg. of Boston IEEE, Mitre Corp, Bedford, Ma 13 October 1976.
Topic:
signal processing
R&D area:
R&D group:

Summary

During the last few years, the Radar Techniques Group at Lincoln Laboratory has been applying digital processing techniques to the problem of automatic detection of moving vehicles in the presence of ground and weather clutter. An outgrowth of this effort is the development of a real-time radar signal processor, the Parallel Microprogrammable Processor, or PMP. Conceptually the PMP consists of a single control unit and an array of identical processing modules. The control unit sequences through a program stored in its control memory, providing identical instructions to each processing module, so that all modules are performing the same operation in parallel, each on its own set of data. The talk will focus on the motivation for, and advantages of such a parallel architecture, as presently implemented with TTL medium-scale integrated circuits. Some examples of parallel computation will be illustrated as well as more general issues relating to programmability of the PMP. Much of the information in the talk will be based on experience with an operational prototype, which has a control unit and one processor module.
READ LESS

Summary

During the last few years, the Radar Techniques Group at Lincoln Laboratory has been applying digital processing techniques to the problem of automatic detection of moving vehicles in the presence of ground and weather clutter. An outgrowth of this effort is the development of a real-time radar signal processor, the...

READ MORE
The PMP, a programmable radar signal processor

Radar detection of thunderstorm hazards for air traffic control volume II: radar systems

October 7, 1976
  |
Project Report
Author:
Steven M. Sussman
Published in:
MIT Lincoln Laboratory Report ATC-67,II
Topic:
weather
R&D area:
R&D group:

Summary

Radar systems are investigated for the acquisition of weather data to support detection and forecasting of hazardous turbulence associated with individual storm cells. Utilization of the FAA Airport Surveillance Radar (ASR) is explored. The issues of antenna polarization and Sensitivity Time Control (STG) that impact on shared operation for aircraft and weather detection are addressed. Candidate system configurations employing a common RF channel and dual orthogonal polarization channels are discussed. Ground clutter discrimination by coherent Doppler and noncoherent (Doppler spread) processing methods is described. An interim procedure is suggested for obtaining fixed reflectivity contour data from a Moving Target Detector for use in the all-digital ARTS. A preliminary design is presented for a new joint-use, long-range weather radar to support enroute air traffic controllers and to meet the data requirements of the National Weather Service and the Air Weather Service.
READ LESS

Summary

Radar systems are investigated for the acquisition of weather data to support detection and forecasting of hazardous turbulence associated with individual storm cells. Utilization of the FAA Airport Surveillance Radar (ASR) is explored. The issues of antenna polarization and Sensitivity Time Control (STG) that impact on shared operation for aircraft...

READ MORE
Radar detection of thunderstorm hazards for air traffic control volume II: radar systems
171-180 of 210