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The influence of surveillance system parameters on automated conflict detection and resolution

November 29, 1972
  |
Project Report
Author:
John W. Andrews
…
Published in:
MIT Lincoln Laboratory Report ATC-15
Topic:
collision avoidance
R&D area:
R&D group:

Summary

The effects of sensor accuracy, data rate, and message delivery delay upon automated conflict detection,and resolution processing is analyzed and particular considerations for DABS/IPC operation are discussed. Various options in the design of the algorithmic logic are enumerated and a particular logic is chosen for quantitative inspection. Performance sensitivity calculations for the conflict detection and command generation functions are then presented. The influence of algorithmic logic and traffic environment upon surveillance requirements is delineated.
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Summary

The effects of sensor accuracy, data rate, and message delivery delay upon automated conflict detection,and resolution processing is analyzed and particular considerations for DABS/IPC operation are discussed. Various options in the design of the algorithmic logic are enumerated and a particular logic is chosen for quantitative inspection. Performance sensitivity calculations...

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The influence of surveillance system parameters on automated conflict detection and resolution

A theory for optimal MTI digital signal processing, supplement I

October 30, 1972
  |
Technical Report
Author:
Robert J. McAulay
Published in:
MIT Lincoln Laboratory Report TN-1972-14-SUP-I
Topic:
signal processing
R&D area:
R&D group:

Summary

In the report, "A Theory for Optimal MTI Digital Signal Processing. Part I. Receiver Synthesis," (1), the problem of eliminating scanning ground clutter from an aircraft surveillance radar was examined from a statistical decision theoretical point of view. An optimum processor was derived which could be approximated by a clutter filter followed by a discrete Fourier transform (DFT). In this report, additional numerical work is documented that compares the performance of the pulse cancellers, pulse cancellers with feedback and the DFT with that of the optimum processor. The issue of coherent vs incoherent integration gain is considered by comparing the filters only on their ability to reject clutter. A clutter rejection improvement factor is defined and used to compare the various filters. It is shown that the pulse cancellers can be quite effective in rejecting clutter provided the input clutter power is not too large and that additional gains are possible using the DFT.
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Summary

In the report, "A Theory for Optimal MTI Digital Signal Processing. Part I. Receiver Synthesis," (1), the problem of eliminating scanning ground clutter from an aircraft surveillance radar was examined from a statistical decision theoretical point of view. An optimum processor was derived which could be approximated by a clutter...

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A theory for optimal MTI digital signal processing, supplement I

An experimental UHF ground surveillance radar, volume II

October 12, 1972
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Technical Report
Author:
Lincoln Cartledge
…
Published in:
MIT Lincoln Laboratory Report TR-497-II
Topic:
radar
R&D area:
R&D group:

Summary

This is Volume 2 of the final report summarizing two years of work on ground-based foliage-penetration radar. The design and implementation of a breadboard radar system and of a theoretical and experimental investigation of target and propagation phenomena specific to the foliage-penetration problem are described. Volume 1 comprises three main sections: a short introduction; an overall description of the radar; and detailed descriptions of the hardware and software subsystems in the radar. Volume 2 describes the use of the radar as a measurements system for studying targets and the clutter environment, in addition to its use for demonstrating the feasibility of radar detection of walking men in foliage. Investigations of target return spectra, clutter return spectra, and clutter return amplitude statistics are reported. Theoretical models relating clutter spectra to wind turbulence and tree resonances are presented and compared with experimental results. Similarly, a previous theoretical prediction of target return spectra is compared with experimental results. Clutter return amplitude statistics are measured and found to be Gaussian under certain conditions. Finally, Vol.2 contains some comments on the relationships between the subclutter visibility and various parameters of digital MTI systems.
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Summary

This is Volume 2 of the final report summarizing two years of work on ground-based foliage-penetration radar. The design and implementation of a breadboard radar system and of a theoretical and experimental investigation of target and propagation phenomena specific to the foliage-penetration problem are described. Volume 1 comprises three main...

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An experimental UHF ground surveillance radar, volume II

A theory for optimal MTI digital signal processing, part II. signal design

October 4, 1972
  |
Technical Report
Author:
Robert J. McAulay
Published in:
MIT Lincoln Laboratory Report TN-1972-14-II
Topic:
air traffic control
R&D area:
R&D group:

Summary

In Part I of this report the optimum MTI receiver was derived and analyzed for the case in which the radar pulses were emitted from the transmitter equally spaced in time. For typical long range ATC surveillance radars , aliasing of the target and clutter spectra results in detection blind speeds at multiples of approximately 70 knots. It is well known operationally that these blind speeds can be eliminated by staggering the transmitter PRF. Heretofore, there has been no thorough theoretical analysis of the effect of staggered PRF on the spectral distribution of the target and clutter signals. It is shown in Part II that the clutter spectral density continues to fold over at the PRF, but that the signal spectrum becomes dispersed in frequency, somewhat like an anti-jam signal. The effect that this phenomenon has on the performance of the optimum processor is evaluated in terms of the signal-to-interference ratio (SIR) criterion that was derived in Part I. It is further noted that even when the target Doppler shifts are more than one PRF apart, the spectra are distinguishable, suggesting that unambiguous Doppler estimation may be possible. This concept is explored in detail using the MTI ambiguity function. It is shown that good SIR performance can be obtained by choosing the stagger parameters to minimize the height of the subsidiary Doppler side-lobes. The resulting design problem is noted to be similar to that of obtaining good antenna patterns for arrays having non-uniformly spaced elements.
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Summary

In Part I of this report the optimum MTI receiver was derived and analyzed for the case in which the radar pulses were emitted from the transmitter equally spaced in time. For typical long range ATC surveillance radars , aliasing of the target and clutter spectra results in detection blind...

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A theory for optimal MTI digital signal processing, part II. signal design

Dual lane runway study, interim report, Project 082-421-214

September 14, 1972
  |
Project Report
Author:
Victor S. Dolat
…
Published in:
Project Report ATC-11, MIT Lincoln Laboratory
Topic:
air traffic control
R&D area:
R&D group:

Summary

An overview of the issues involved in the design of dual lane runways is presented. These issues include: centerline spacing, parallel taxiway, high speed exits, midpoint versus end point crossing, threshold stagger, and departure/arrival runway preference. An interactive graphics simulation was developed on the TX-2 computer. The simulation provides the capability for an airport designer to easily input dual lane runway configurations. ATC controllers were employed for over 100 hours to control and direct simulated traffic to various dual lane configurations. A set of preliminary criteria for dual lane runway configurations are presented along with recommendations for future work.
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Summary

An overview of the issues involved in the design of dual lane runways is presented. These issues include: centerline spacing, parallel taxiway, high speed exits, midpoint versus end point crossing, threshold stagger, and departure/arrival runway preference. An interactive graphics simulation was developed on the TX-2 computer. The simulation provides the...

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Dual lane runway study, interim report, Project 082-421-214

Comparison of immunity to garbling for three candidate modulation schemes for DABS

August 14, 1972
  |
Project Report
Author:
David A. Shnidman
Published in:
MIT Lincoln Laboratory Report ATC-12
Topic:
surveillance
R&D area:
R&D group:

Summary

The performance of three candidate modulation schemes for DABS is analyzed in this report and a comparison on the basis of probability of error per bit is made. The three types of modulation are PAM, DPSK, and FSK. The results show that, at a given level of interference and signal-to-noise ratio, DPSK and FSK have a lower P(e)/bit than PAM and this difference is significant in most cases. In addition to P(e)/bit, however, the choice of modulation and message format depends on the capacity required, bandwidth occupancy, and cost of implementation. This list consideration is especially important with regard to the transponder.
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Summary

The performance of three candidate modulation schemes for DABS is analyzed in this report and a comparison on the basis of probability of error per bit is made. The three types of modulation are PAM, DPSK, and FSK. The results show that, at a given level of interference and signal-to-noise...

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Comparison of immunity to garbling for three candidate modulation schemes for DABS

Parallel approach surveillance

August 14, 1972
  |
Project Report
Author:
John B. Allen
…
Published in:
MIT Lincoln Laboratory Report ATC-13
Topic:
surveillance
R&D area:
R&D group:

Summary

This report investigates the requirements imposed on a surveillance system for supporting independent approaches to closely spaced parallel runways. Based on a proposed procedure for monitoring aircraft approach paths and controlling deviations from proper approach paths, the required spacing between runway centerlines is derived as a function of surveillance system characteristics and other parameters. Potential trade-offs between the surveillance system characteristics are then investigated to determine whether the DABS sensor might be utilized for position measurement and/or communication in such a surveillance system. The results indicate that the required runway spacing is more sensitive to delays and data update intervals than to position measurement accuracies, and that, if DABS is to perform the communication function in the system, it should probably be used for position measurement as well.
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Summary

This report investigates the requirements imposed on a surveillance system for supporting independent approaches to closely spaced parallel runways. Based on a proposed procedure for monitoring aircraft approach paths and controlling deviations from proper approach paths, the required spacing between runway centerlines is derived as a function of surveillance system...

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Parallel approach surveillance

Surveillance aspects of the Advanced Air Traffic Management System

June 22, 1972
  |
Project Report
Author:
Adrian E. Eckberg Jr
…
Published in:
MIT Lincoln Laboratory Report ATC-10
Topic:
surveillance
R&D area:
R&D group:

Summary

Three topics with impact on the performance of Air-to Satellite-to-Ground Systems for Air Traffic Control Surveillance are addressed in detail: 1) vulnerability to intentional jamming; 2) performance degradation due to the multiple access noise which results from uncoordinated aircraft transmissions, and 3) tracking techniques for improved surveillance accuracy and reduced short-term outages.
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Summary

Three topics with impact on the performance of Air-to Satellite-to-Ground Systems for Air Traffic Control Surveillance are addressed in detail: 1) vulnerability to intentional jamming; 2) performance degradation due to the multiple access noise which results from uncoordinated aircraft transmissions, and 3) tracking techniques for improved surveillance accuracy and reduced...

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Surveillance aspects of the Advanced Air Traffic Management System

Final Report: Transponder Test Program

April 12, 1972
  |
Project Report
Author:
George V. Colby
…
Published in:
MIT Lincoln Laboratory Report ATC-9
Topic:
surveillance
R&D area:
R&D group:

Summary

Performance parameters of transponders installed in aircraft were measured to determine their degree of compliance with current specifications. A mobile van was outfitted with electronic test equipment which simulated the transmitter and receiver sections of a ground interrogator and which allowed measurement of transponder parameters. A horn antenna located near the aircraft under test was used to couple signals to and from the transponder. The results of measuremetns on 504 transponders installed in general aviation aircraft, 17 transponders installed in military aircraft, and 28 transponders installed in air carrier aircraft are reported. Of these, 31 general aviation, 2 military, and one air carrier transponders were inoperative. The results of measurements of reply frequency, squitter, delay, Mode C operation, dead time, P2/P1 ratio required for suppression, suppression time, framing pulse spacing, power output and sensitivity are included.
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Summary

Performance parameters of transponders installed in aircraft were measured to determine their degree of compliance with current specifications. A mobile van was outfitted with electronic test equipment which simulated the transmitter and receiver sections of a ground interrogator and which allowed measurement of transponder parameters. A horn antenna located near...

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Final Report: Transponder Test Program

A theory for optimal MTI digital signal processing, part I. receiver synthesis

February 22, 1972
  |
Technical Report
Author:
Robert J. McAulay
Published in:
MIT Lincoln Laboratory Report TN-1972-14-I
Topic:
air traffic control
R&D area:
R&D group:

Summary

A classical problem in radar theory is the detection of moving targets in a ground clutter plus receiver noise background. Improvements in clutter rejection have recently been made by replacing analog MTI processors by their digital equivalents as this eliminates many of the problems associated with the maintenance of the analog hardware. In an attempt to determine the ultimate improvements possible using this new technology, the MTI problem was formulated as a classical detection problem and solved using the generalized likelihood ratio test. By manipulating the likelihood ratio, the receiver could be interpreted as a clutter filter in cascade with a Doppler filter bank. The performance of the optimum receiver was evaluated in terms of the output signal-to-interference ratio and compared with well-known MTI processors. It was shown that near-optimum performance can be obtained using a sliding weighted Discrete Fourier Transform (DFT). All of the results in Part I assume uniformly spaced transmitted pulses, which, for high velocity aircraft, leads to aliasing of the target and clutter spectra and detection blind speeds. In Part II the maximum likelihood method is applied using a more general model for the non-uniformly sampled target returns. This leads to an optimum receiver that is a slightly more complicated version of the sliding weighted DFT. In addition to removing the detection blind speeds, it is found that unambiguous Doppler measurements
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Summary

A classical problem in radar theory is the detection of moving targets in a ground clutter plus receiver noise background. Improvements in clutter rejection have recently been made by replacing analog MTI processors by their digital equivalents as this eliminates many of the problems associated with the maintenance of the...

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A theory for optimal MTI digital signal processing, part I. receiver synthesis
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