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Registration errors in a netted air surveillance system

September 2, 1980
  |
Technical Report
Author:
William L. Fischer
…
Published in:
MIT Lincoln Laboratory Report TN-1980-40
Topic:
radar
R&D area:
R&D group:

Summary

Today's tactical military air surveillance radars generally operate in a stand-alone configuration. The many performance improvements that result when data from multiple radars of this type are merged have made such netted operations an attractive goal for many years. A major obstacle to achieving this goal has traditionally been the difficulty associated with the registration of multisensor data, the expression of the data in a common coordinate system free from errors due to site uncertainty, antenna orientation, and improper alignment. This report presents the results of a modest effort to develop a self-registration procedure by which multiple radar sensors operating in consort each calculate the errors In their data by comparing it with data from the remainder of the system and then uses the information to upgrade performance. The technique has been tested with experimental data and appears quite capable of improving system performance, measured in terms of residual inter-site bias errors, by almost a factor of one hundred.
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Summary

Today's tactical military air surveillance radars generally operate in a stand-alone configuration. The many performance improvements that result when data from multiple radars of this type are merged have made such netted operations an attractive goal for many years. A major obstacle to achieving this goal has traditionally been the...

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Registration errors in a netted air surveillance system

Automated tracking for aircraft surveillance radar systems

January 1, 1979
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Conference Paper
Author:
Robert M. O'Donnell
…
Published in:
IEEE Trans. Aerosp. Electron. Syst., Vol. AES-15, No. 4, July 1979, pp. 508-517.
Topic:
detection systems
R&D area:
R&D group:

Summary

An improved moving target detector (MTD) (a digital signal processor) has been designed, constructed, and tested which successfully rejects all forms of radar clutter while providing reliable detection of all aircraft within the coverage of the radar. The MTD is being tested on both terminal and enroute surveillance radars for the FAA. This processor has been integrated with automatic tracking algorithms to give complete rejection of ground clutter, heavy precipitation, and angels (birds).
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Summary

An improved moving target detector (MTD) (a digital signal processor) has been designed, constructed, and tested which successfully rejects all forms of radar clutter while providing reliable detection of all aircraft within the coverage of the radar. The MTD is being tested on both terminal and enroute surveillance radars for...

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Automated tracking for aircraft surveillance radar systems

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

Airborne radars for surveillance and weapon delivery

July 15, 1977
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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.
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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...

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Airborne radars for surveillance and weapon delivery

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

Advances in radar signal processing

May 14, 1976
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Conference Paper
Author:
Charles E. Muehe
Published in:
Electro/76, 11-14 May 1976.
Topic:
radar
R&D area:
R&D group:

Summary

The recent availability of new solid-state digital components has made possible the development of radar signal processing techniques only dreamed of in the past. The philosophy and design of these techniques is described in terms of a new signal processor for Airport Surveillance Radars called the Moving Target Detector (MTD). Test results showing greatly improved automatic aircraft acquisition and tracking are discussed.
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Summary

The recent availability of new solid-state digital components has made possible the development of radar signal processing techniques only dreamed of in the past. The philosophy and design of these techniques is described in terms of a new signal processor for Airport Surveillance Radars called the Moving Target Detector (MTD)...

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Advances in radar signal processing

New techniques applied to air-traffic control radars

June 1, 1974
  |
Journal Article
Author:
Charles E. Muehe
…
Published in:
Proc. IEEE, Vol. 62, No. 6, June 1974, pp. 716-723.
Topic:
air traffic control
R&D area:
R&D group:

Summary

During the past two years a program has been carried out to show how new techniques can greatly improve the performance of radars used for air-traffic control. A survey of problems associated with presently used radars was undertaken. This survey indicates that primary radar in an automated air-traffic control system can be made significantly more effective by the use of new techniques. The radar's handling of extraneous reflections (clutter) is critical to its performance. Three types of interfering clutter were found to predominate: ground clutter, weather clutter, and angels. Angels are generally accepted to be radar returns from flocks of birds. In addition, second-time-around clutter is often troublesome. For each type of clutter, all known remedies for improving the signal-to-clutter ratio were studied and radar systems were configured using appropriate sets of remedies. Some specific solutions incorporated in the resulting radar systems are: a) the use of linear large dynamic range, near-optimum digital signal processors to filter signals from clutter, b) the use of electronically step-scanned antennas to improve the correlation of aircraft and clutter returns from pulse to pulse, c) the use of multiple PRF's instead of staggered PRF's together with coherent transmitters to keep second-time-around clutter returns well correlated while still overcoming blind speeds, d) the use of a fine grained ground clutter map to give superclutter visibility on tangential targets, and e) the use of lower operating frequencies to greatly reduce weather and angel returns. Two demonstration radar systems have been implemented, an S-band radar using a mechanically rotating antenna and a UHF radar using an electronically step-scanned cylindrical antenna. Experimental results are described.
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Summary

During the past two years a program has been carried out to show how new techniques can greatly improve the performance of radars used for air-traffic control. A survey of problems associated with presently used radars was undertaken. This survey indicates that primary radar in an automated air-traffic control system...

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New techniques applied to air-traffic control radars

Digital signal processor for air traffic control radars

January 1, 1974
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Conference Paper
Author:
Charles E. Muehe
Published in:
Northeast Electronics Research and Engineering Meeting, NEREM, 28-31 October 1974.
Topic:
air traffic control
R&D area:
R&D group:

Summary

At a previous NEREM Meeting [1] and in a subsequent paper [2], we described the general philosophy and particular ideas which can be used to overcome the problems associated with achieving good radar detection performance in the presence of various types of clutter; ground clutter (including second-time-around returns ), weather clutter and angels (bird flocks). Recently, a digital signal processor called an MTD (Moving Target Detector) has been designed and built for application to an S-band ASR (Airport Surveillance Radar). This paper describes the MTD and presents some preliminary test results. The MTD is a special purpose hard-wired digital signal processor which is capable of processing a full 360 coverage in 1/16 nmi steps out to a nominal range of 48 nmi. The MTD was designed to provide digital radar output to an automated air traffic control system.
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Summary

At a previous NEREM Meeting [1] and in a subsequent paper [2], we described the general philosophy and particular ideas which can be used to overcome the problems associated with achieving good radar detection performance in the presence of various types of clutter; ground clutter (including second-time-around returns ), weather...

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Digital signal processor for air traffic control radars

Recent advances in air traffic control radars

June 26, 1973
  |
Conference Paper
Author:
Charles E. Muehe
Published in:
IEEE Northeast Electronic Research and Engineering Meeting, NEREM, 8 November 1973.
Topic:
air traffic control
R&D area:
R&D group:

Summary

This paper describes recent improvements in microwave radars used for air traffic control. These improvements have been designed to increase the target-to-clutter ratio so that adaptive thresholding can be used to give a very low false alarm rate and high probability of detection even when the aircraft target is in the presence of strong clutter. Studies show that detection suffers when three types of clutter returns are strong; namely, ground clutter, weather clutter or angels. Angels have been almost universally identified as bird flocks. Under certain terrain and propagation conditions, second-time-around clutter can also be a problem. Here ground returns from the second to last transmitted pulse are received from targets beyond the nonambiguous range. These may be from mountains or from the ground when anomalous propagation conditions occur. Meaningful improvements in this class of radar can be conveniently grouped as shown in Table I. We will briefly discuss each of the three classes listed.
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Summary

This paper describes recent improvements in microwave radars used for air traffic control. These improvements have been designed to increase the target-to-clutter ratio so that adaptive thresholding can be used to give a very low false alarm rate and high probability of detection even when the aircraft target is in...

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Recent advances in air traffic control radars

Concepts for improvement of airport surveillance radars

February 26, 1973
  |
Project Report
Author:
Charles E. Muehe
…
Published in:
MIT Lincoln Laboratory Report ATC-14
Topic:
radar
R&D area:
R&D group:

Summary

This report reviews the performance of operational ASR's, discusses each type of clutter with which the target must compete, examines presently employed methods of overcoming clutter and several state-of-the-art techniques which have not found their way into the ASR's for one reason or another. It concludes by describing two radars, one at S-band and one at UHF, which are believed to come closest to fulfilling ASR requirements in advanced ARTS facilities. The major improvements in performance will be derived from the use of linear optimum signal processing. Further gains will be achieved through the use of adaptive thresholds. STC will combat bird clutter. The radar will incorporate proper shaping of the antenna pattern so that aircraft off the peak of the antenna elevation beam will not be at a disadvantage compared to moving clutter at the peak. The recommended radar concepts also include radial velocity determination by Doppler measurement. This should prove of value in maintaining target tracks and in discrimination against ground vehicles.
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Summary

This report reviews the performance of operational ASR's, discusses each type of clutter with which the target must compete, examines presently employed methods of overcoming clutter and several state-of-the-art techniques which have not found their way into the ASR's for one reason or another. It concludes by describing two radars...

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Concepts for improvement of airport surveillance radars
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