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Energy onset times for speaker identification

November 1, 1994
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Journal Article
Author:
Thomas F. Quatieri
…
Published in:
IEEE Signal Process. Lett., Vol. 1, No. 11, November 1994, pp. 160-162.
Topic:
speaker recognition
R&D area:
R&D group:

Summary

Onset times of resonant energy pulses are measured with the high-resolution Teager operator and used as features in the Reynolds Gaussian-mixture speaker identification algorithm. Feature sets are constructed with primary pitch and secondary pulse locations derived from low and high speech formants. Preliminary testing was performed with a confusable 40-speaker subset from the NTIMIT (telephone channel) database. Speaker identification improved from 55 to 70% correct classification when the full set of new resonant energy-based features were added as an independent stream to conventional mel-cepstra.
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Summary

Onset times of resonant energy pulses are measured with the high-resolution Teager operator and used as features in the Reynolds Gaussian-mixture speaker identification algorithm. Feature sets are constructed with primary pitch and secondary pulse locations derived from low and high speech formants. Preliminary testing was performed with a confusable 40-speaker...

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Energy onset times for speaker identification

GPS-squitter experimental results

October 30, 1994
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Conference Paper
Author:
Robert E. Boisvert
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Published in:
13th AIAA/IEEE Digital Avionics Systems Conf., 30 October - 3 November 1994, pp. 521-527.
Topic:
airborne surveillance
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Summary

GPS-Squitter is a system concept that merges the capabilities of Automatic Dependent Surveillance (ADS) and the Mode S beacon radar. The result is an integrated concept for seamless surveillance and data link that permits equipped aircraft to participate in ADS or beacon ground environments. This offers many possibilities for transition from beacon to ADS-based surveillance. This paper briefly defines the GPS-Squitter concept and its principal applications. The thrust of the paper is the presentation of surface and airborne surveillance measurements made at Hanscom Field in Bedford, Massachusetts and at the Logan International Airport in Boston. In each case the measurements show the excellent surveillance performance provided by this concept.
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Summary

GPS-Squitter is a system concept that merges the capabilities of Automatic Dependent Surveillance (ADS) and the Mode S beacon radar. The result is an integrated concept for seamless surveillance and data link that permits equipped aircraft to participate in ADS or beacon ground environments. This offers many possibilities for transition...

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GPS-squitter experimental results

Formant AM-FM for speaker identification

October 25, 1994
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Conference Paper
Author:
Charles R. Jankowski Jr
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Published in:
Proc. IEEE-SP Int. Symp. on Time-Frequency and Time-Scale Analysis, 25-28 October 1994, pp. 608-611.
Topic:
speaker recognition
R&D area:
R&D group:

Summary

The performance of systems for speaker identification (SID) can be quite good with clean speech, though much lower with degraded speech. Thus it is useful to search for new features for SID, particularly features that are robust over a degraded channel. This paper investigates features that are robust over a degraded channel. This paper investigates features that are based on amplitude and frequency modulations of speech formants. Such modulations are measured using a high-resolution energy operator and related algorithms for recovering amplitude and frequency from an AM-FM signal. When these features are added to traditional features using an existing SID system with a telephone speech database, SID performance improved by as much as 15%. Energy onset time measurements that yielded improved SID performance are also discussed.
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Summary

The performance of systems for speaker identification (SID) can be quite good with clean speech, though much lower with degraded speech. Thus it is useful to search for new features for SID, particularly features that are robust over a degraded channel. This paper investigates features that are robust over a...

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Formant AM-FM for speaker identification

Summer 1992 Terminal area-Local Analysis and Prediction System (T-LAPS) evaluation

October 7, 1994
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Project Report
Author:
Steven R. Finch
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Published in:
MIT Lincoln Laboratory Report ATC-218
Topic:
sensors
R&D area:
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Summary

The Integrated Terminal Weather System (ITWS) is a development program initiated by the Federal Administration (FAA) to produce a fully automated, integrated terminal weather information system to improve the safety, efficiency and capacity of terminal area aviation operations. The ITWS will acquire data from FAA and National Weather Service sensors as well as from aircraft in flight in the terminal area. The ITWS will provide Air Traffic personnel with products that are immediately usable without further meteorological interpretation. Among the products are current terminal area weather, short-term (0-30 minute) predictions of significant weather phenomena, and the Terminal Winds product. The terminal winds product is the component of the ITWS which produces estimates of the horizontal winds on a three dimensional grid of points encompassing an airport terminal region. It uses information from a variety of sensors, including Doppler weather radars. In 1992, an operational test of an initial prototype Terminal Winds system was conducted at the MIT Lincoln Laboratory testbed in Orlando, FL. This report describes our evalution of the initial Terminal Winds prototype.
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Summary

The Integrated Terminal Weather System (ITWS) is a development program initiated by the Federal Administration (FAA) to produce a fully automated, integrated terminal weather information system to improve the safety, efficiency and capacity of terminal area aviation operations. The ITWS will acquire data from FAA and National Weather Service sensors...

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Summer 1992 Terminal area-Local Analysis and Prediction System (T-LAPS) evaluation

Experimental evaluation of features for robust speaker identification

October 1, 1994
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Journal Article
Author:
Douglas A. Reynolds
Published in:
IEEE Trans. Speech Audio Process., Vol. 2, No. 4, October 1994, pp. 639-643.
Topic:
speaker recognition
R&D area:
R&D group:

Summary

This correspondence presents an experimental evaluation of different features and channel compensation techniques for robust speaker identification. The goal is to keep all processing and classification steps constant and to vary only the features and compensations used to allow a controlled comparison. A general, maximum-likelihood classifier based on Gaussian mixture densities is used as the classifier, and experiments are conducted on the King speech database, a conversational, telephone-speech database. The features examined are mel-frequency and linear-frequency filterbank cepstral coefficients, linear prediction ceptral coefficients. The channel compensation techniques examined are cepstral mean removal, RASTA processing, and a quadratic trend removal technique. It is shown for this database that performance difference between the basic features is small, and the major gains are due to the channel compensation techniques. The best "across-the-divide" recognition accuracy of 92% is obtained for both high-order LPC features and band-limited filterbank features.
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Summary

This correspondence presents an experimental evaluation of different features and channel compensation techniques for robust speaker identification. The goal is to keep all processing and classification steps constant and to vary only the features and compensations used to allow a controlled comparison. A general, maximum-likelihood classifier based on Gaussian mixture...

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Experimental evaluation of features for robust speaker identification

TDWR scan strategy implementation

September 2, 1994
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Project Report
Author:
Daniel P. Hynek
Published in:
MIT Lincoln Laboratory Report ATC-222
Topic:
radar
R&D area:
R&D group:

Summary

The Terminal Doppler Weather Radars (TDWRs) installed at major airports around the country are intended to enhance the safety of air travel by the detection and timely warning of hazardous wind shear conditions in the airport terminal area. To meet these objectives, scan strategies to efficiently cover the protected airspace were developed after extensive testing at several sites with different meteorological environments. Since the topology and geometry differ at each TDWR location, special considerations were necessary to define the specific scan sequences for each site. This report describes the criteria used to establish these scan sequences, including the determination of the lowest practicable elevation angle for each site - the "surface scan," which is used to detect microburst surface outflows, and other special scans such as the "MTS scan," which is used to illuminate the remote Moving Target Simulator (MTS).
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Summary

The Terminal Doppler Weather Radars (TDWRs) installed at major airports around the country are intended to enhance the safety of air travel by the detection and timely warning of hazardous wind shear conditions in the airport terminal area. To meet these objectives, scan strategies to efficiently cover the protected airspace...

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TDWR scan strategy implementation

Air traffic control development at Lincoln Laboratory

September 1, 1994
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Journal Article
Author:
John C. Fielding
Published in:
Lincoln Laboratory Journal, Vol. 7, No. 2, Fall 1994, pp. 147-148.
Topic:
air traffic control
R&D area:
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Summary

Lincoln Laboratory-developed air traffic control technologies, which were described in the Fall 1989 issue of this journal, are now in operational use. These technologies include the Mode-Select beacon system, the Traffic Alert and Collision Avoidance System, the Precision Runway Monitor system, the Terminal Doppler Weather Radar, and the Moving Target Detector signal processor used in the current generation of Airport Surveillance Radars. Our newest efforts focus on utilization of the Global Positioning System for both navigation and surveillance, and on the development of automation aids for air traffic control and management.
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Summary

Lincoln Laboratory-developed air traffic control technologies, which were described in the Fall 1989 issue of this journal, are now in operational use. These technologies include the Mode-Select beacon system, the Traffic Alert and Collision Avoidance System, the Precision Runway Monitor system, the Terminal Doppler Weather Radar, and the Moving Target...

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Air traffic control development at Lincoln Laboratory

Automated microburst wind-shear prediction

September 1, 1994
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Journal Article
Author:
Marilyn M. Wolfson
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Published in:
Lincoln Laboratory Journal, Vol. 7, No. 2, Fall 1994, pp. 399-426.
Topic:
algorithms
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Summary

We have developed an algorithm that automatically and reliably predicts microburst wind shear. The algorithm, developed as part of the FAA Integrated Terminal Weather System (ITWS), can provide warnings several minutes in advance of hazardous low-altitude wind-shear conditions. Our approach to the algorithm emphasizes fundamental principles of thunderstorm evolution and downdraft development and incorporates heuristic and statistical methods as needed for refinement. In the algorithm, machine-intelligent image processing and data-fusion techniques are applied to Doppler radar data to detect those regions of growing thunderstorms and intensifying downdrafts which lead to microbursts. The algorithm then uses measurements of the ambient temperature/humidity structure in the atmosphere to aid in predicting a microburst's peak outflow strength. The algorithm has been tested in real time as part of the ITWS operational test and evaluation at Memphis, Tennessee, and Orlando, Florida, in 1994.
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Summary

We have developed an algorithm that automatically and reliably predicts microburst wind shear. The algorithm, developed as part of the FAA Integrated Terminal Weather System (ITWS), can provide warnings several minutes in advance of hazardous low-altitude wind-shear conditions. Our approach to the algorithm emphasizes fundamental principles of thunderstorm evolution and...

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Automated microburst wind-shear prediction

Evaluation of runway-assignment and aircraft-sequencing algorithms in terminal area automation

September 1, 1994
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Journal Article
Author:
Herman F. Vandevenne
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Published in:
Lincoln Laboratory Journal, Vol. 7, No. 2, Fall 1994, pp. 215-238.
Topic:
air traffic control
R&D area:
R&D group:

Summary

The Federal Aviation Administration has responded to the steady growth of air traffic and the ensuing increase in delays at airports by initiating new programs for increasing the efficiency of existing air traffic control facilities. The Terminal Air Traffic Control Automation (TATCA) program is intended to increase efficiency by providing controllers with planning aids and advisories to help them in vectoring, sequencing, and spacing traffic arriving at busy airports. Two important algorithms in this system allocate arrivals to multiple runways and set up the best sequences for landing aircraft. This article evaluates the potential for such algorithms to achieve higher throughput with less delay. The results show that, at airports with multiple active runways, the introduction of algorithms for systematic allocation of runways increases throughput considerably. These algorithms are in fact more effective than algorithms that aim at generating optimal landing sequences based on aircraft weight-class inputs. This result is fortuitous because algorithms for optimal sequencing are significantly more difficult to implement in practice than are algorithms for runway allocation. This study also provides a scientific basis for estimating future benefits of terminal automation by using traffic models patterned on actual recorded traffic-flow data, and by proposing a unified method for assessing performance.
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Summary

The Federal Aviation Administration has responded to the steady growth of air traffic and the ensuing increase in delays at airports by initiating new programs for increasing the efficiency of existing air traffic control facilities. The Terminal Air Traffic Control Automation (TATCA) program is intended to increase efficiency by providing...

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Evaluation of runway-assignment and aircraft-sequencing algorithms in terminal area automation

Performance of the runway-status light system at Logan Airport

September 1, 1994
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Journal Article
Author:
Harald Wilhelmsen
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Published in:
Lincoln Laboratory Journal, Vol. 7, No. 2, Fall 1994, pp. 187-214.
R&D area:
R&D group:

Summary

"Runway incursions are a persistent problem in airport ground-movement operations. Numerous critical conflicts and several fatal accidents have occurred as a result of unauthorized or otherwise inappropriate entry of aircraft or surface vehicles onto an active runway. Many of these conflicts developed quickly, leaving little time for effective intervention by either the controller or the pilots involved. A reliable system of automatic runway-status lights would be an effective way to prevent such time-critical incursions. The runway-status light system (RSLS) at Boston's Logan International Airport is an off-line proof-of-concept technology-demonstration system designed to show that automatically operated runway-status lights can promptly and reliably transmit runway-status information to pilots and surface-vehicle operators, thereby preventing unsafe runway entry or unsafe takeoff. The demonstration system does not include actual lights on the airport surface but has relied instead on an illuminated airport model board, which has allowed system development to proceed in a realistic operating environment of live airport traffic without interfering with airport operations. The results of an initial proof-of-concept assessment indicate that the system performs well, even though it is an early prototype. Missed-detection and false-alarm rates are low, and interference with normal airport operations promises to be negligible. The demonstration has shown the technical feasibility of a system of automatic runway-status lights.
"
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Summary

"Runway incursions are a persistent problem in airport ground-movement operations. Numerous critical conflicts and several fatal accidents have occurred as a result of unauthorized or otherwise inappropriate entry of aircraft or surface vehicles onto an active runway. Many of these conflicts developed quickly, leaving little time for effective intervention by...

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Performance of the runway-status light system at Logan Airport
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