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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

Recursive two-dimensional signal reconstruction from linear system input and output magnitudes

May 1, 1981
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Journal Article
Author:
Thomas F. Quatieri
Published in:
Proc. IEEE, Vol. 69, No. 5, May 1981, pp. 667-668.
Topic:
signal processing
R&D area:
R&D group:

Summary

A recursive algorithm is presented for reconstructing a two-dimensional complex signal from its magnitude and the magnitude of the output of a known linear shift-invariant system whose input is the desired signal. The recursion has a simple geometric interpretation, and is easily extended to causal, shift-varying systems.
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Summary

A recursive algorithm is presented for reconstructing a two-dimensional complex signal from its magnitude and the magnitude of the output of a known linear shift-invariant system whose input is the desired signal. The recursion has a simple geometric interpretation, and is easily extended to causal, shift-varying systems.

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Recursive two-dimensional signal reconstruction from linear system input and output magnitudes

Voice communication in integrated digital voice and data networks

September 1, 1980
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Journal Article
Author:
Theodore Bially
…
Published in:
IEEE Trans. Commun., Vol. COM-28, No. 9, September 1980, pp. 1478-90.
Topic:
signal processing
R&D area:
R&D group:

Summary

Voice communication networks have traditionally been designed to provide either analog signal paths or fixed-rate synchronous digital connections between individual subscribers. These designs were aimed at accommodating the "streamlike" character of speech, which has traditionally been considered to flow from source to destination at a more or less constant rate. By way of contrast, interactive and computer-to-computer data transactions tend to be "bursty" in nature, and this has given rise to the development of packet-switching methods for data communications. The dichotomous nature of these two major traffic classes and the apparent conflict between the types of network services they require has resulted in the deployment of separate military communications facilities for voice and data. A challenge in the design of future systems is to achieve overall economy and flexibility in the allocation of resources via the efficient integration of both traffic types in common network facilities. This paper summarizes a number of advanced concepts for switching and flow control of combined voice and data traffic in integrated environments. Performance characteristics are described based on analysis results and computer simulation studies for both multilink terrestrial and broadcast satellite network topologies.
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Summary

Voice communication networks have traditionally been designed to provide either analog signal paths or fixed-rate synchronous digital connections between individual subscribers. These designs were aimed at accommodating the "streamlike" character of speech, which has traditionally been considered to flow from source to destination at a more or less constant rate...

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Voice communication in integrated digital voice and data networks

Convergence of iterative nonexpansive signal reconstruction algorithms

August 1, 1980
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Journal Article
Author:
Victor T. Tom
…
Published in:
IEEE Trans. Acoust. Speech Signal Process., Vol. ASSP-29, No. 5, October 1981, pp. 1052-1059.
Topic:
signal processing
R&D area:
R&D group:

Summary

Iterative algorithms for signal reconstruction from partial time- and frequency-domain knowledge have proven useful in a number of application areas. In this paper, a general convergence proof, applicable to a general class of such iterative reconstruction algorithms, is presented. The proof relies on the concept of a nonexpansive mapping in both the time and frequency domains. Two examples studied in detail are time-limited extrapolation (equivalently, band-limited extrapolation) and phase-only signal reconstruction. The proof of convergence for the phase-only iteration is a new result obtained by this method of proof. The generality of the approach allows the incorporation of nonlinear constraints such as time- (or space-) domain positivity or minimum and maximum value constraints. Finally, the underrelaxed form of these iterations is also shown to converge even when the solution is not guaranteed to be unique.
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Summary

Iterative algorithms for signal reconstruction from partial time- and frequency-domain knowledge have proven useful in a number of application areas. In this paper, a general convergence proof, applicable to a general class of such iterative reconstruction algorithms, is presented. The proof relies on the concept of a nonexpansive mapping in...

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Convergence of iterative nonexpansive signal reconstruction algorithms

Data traffic performance of an integrated circuit and packet-switched multiplex structure

June 1, 1980
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Journal Article
Author:
Marilyn L. Malpass
…
Published in:
IEEE Trans. on Commun., Vol. COM-28, No. 6, June 1980, pp. 873-878.
Topic:
signal processing
R&D area:
R&D group:

Summary

Results are developed for data traffic performance in an integrated multiplex structure which includes circuit-switching for voice and packet-switching for data. The results are obtained both through simulation and analysis, and show that excessive data queues and delays will build up under heavy loading conditions. These large data delays occur during periods of time when the voice traffic load through the multiplexer exceeds its statistical average. A variety of flow control mechanisms to reduce data packet delays are investigated. These mechanisms include control of voice bit rate, limitation of the data buffer, and combinations of voice rate and data buffer control. Simulations indicate that these flow control mechanisms provide substantial improvements in system performance.
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Summary

Results are developed for data traffic performance in an integrated multiplex structure which includes circuit-switching for voice and packet-switching for data. The results are obtained both through simulation and analysis, and show that excessive data queues and delays will build up under heavy loading conditions. These large data delays occur...

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Data traffic performance of an integrated circuit and packet-switched multiplex structure

The tradeoff between delay and TASI advantage in a packetized speech multiplexer

November 1, 1979
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Journal Article
Author:
Clifford J. Weinstein
…
Published in:
IEEE Trans. on Commun., Vol. COM-27, No. 11, November 1979, pp. 1716-20.
Topic:
signal processing
R&D area:
R&D group:

Summary

A packetized speech multiplexer differs from a circuit-switched TASI system in that the presence of a packet buffer allows a tradeoff where the TASI advantage can be increased at a cost in packet delay. This tradeoff is investigated via a simulation. Results are presented to show the relations between TASI advantage and delay, for both an average delay criterion and a maximum delay criterion. It is shown that, particularly for the case where small numbers of talkers are multiplexed, the packetized system offers significant improvements in TASI advantage over the conventional circuit-switched multiplexer, at modest costs in packet delay.
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Summary

A packetized speech multiplexer differs from a circuit-switched TASI system in that the presence of a packet buffer allows a tradeoff where the TASI advantage can be increased at a cost in packet delay. This tradeoff is investigated via a simulation. Results are presented to show the relations between TASI...

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The tradeoff between delay and TASI advantage in a packetized speech multiplexer

Description and performance evaluation of the moving target detector

March 8, 1977
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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.
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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...

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Description and performance evaluation of the moving target detector

The PMP, a programmable radar signal processor

October 7, 1976
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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.
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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...

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The PMP, a programmable radar signal processor

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

Logan MLS multipath experiment

September 23, 1975
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Project Report
Author:
David A. Shnidman
Published in:
MIT Lincoln Laboratory Report ATC-55
Topic:
air traffic control
R&D area:
R&D group:

Summary

The National Plan for a Microwave Landing System (MLS) has specified a carrier frequency for the system in the vicinity of 5.1 GHz. At that frequency, no multipath data taken at a major civilian airport existed. The purpose of this experiment was to obtain such data at Logan International Airport in order to ascertain: 1) which objects are the major causes of measurable multipath reflections and their levels relative to the direct signal (MID level), 2) whether or not the reflections from these objects can be satisfactorily simulated by the Lincoln computer model and, if so, how complicated must that model be, and 3) if the characteristics of multipath provide a significant discriminant between the Doppler and scanning beam techniques. It was found in the experiment that regions where reflections were noted could be predicted from ray optics and diffraction. No measurable reflections were noted elsewhere. For the purpose of modeling for multipath, building surfaces could be characterized as a flat plate with a reflection coefficient determined by measurement if it were a complicated surface, or by the dielectric properties of the surface material, if a simple surface. The airplane reflection model was also found to agree well with measurements.
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Summary

The National Plan for a Microwave Landing System (MLS) has specified a carrier frequency for the system in the vicinity of 5.1 GHz. At that frequency, no multipath data taken at a major civilian airport existed. The purpose of this experiment was to obtain such data at Logan International Airport...

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Logan MLS multipath experiment
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