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A new approach for designing safer collision avoidance systems

June 14, 2011
  |
Conference Paper
Author:
Mykel J. Kochenderfer
…
Published in:
9th USA/Europe Air Traffic Management Research and Development Sem., ATM 2011, 14-17 June 2011.
Topic:
collision avoidance
R&D area:
R&D group:

Summary

The Traffic Alert and Collision Avoidance System (TCAS) has been shown to significantly reduce the risk of mid-air collision and is currently mandated worldwide on all large transport aircraft. Engineering the collision avoidance logic was a very costly undertaking that spanned several decades. The development followed an iterative process where the logic was specified using pseudocode, evaluated on encounters in simulation, and revised based on performance against a set of metrics. Modifying the logic to get the desired behavior is difficult because the pseudocode contains many heuristic rules that interact with each other in complex ways. Over the years, the TCAS logic has become challenging to maintain. With the anticipated introduction of next-generation air traffic control procedures and surveillance systems, the logic will require significant revision to prevent unnecessary alerts. Recent work has explored a new approach for designing collision avoidance systems that has the potential to shorten the development cycle, improve maintainability, and enhance safety with fewer false alerts. The approach involves leveraging recent advances in computation to automatically derive optimized collision avoidance logic directly from encounter models and performance metrics. This paper outlines the general approach and discusses the anticipated impact on development, safety, and operation.
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Summary

The Traffic Alert and Collision Avoidance System (TCAS) has been shown to significantly reduce the risk of mid-air collision and is currently mandated worldwide on all large transport aircraft. Engineering the collision avoidance logic was a very costly undertaking that spanned several decades. The development followed an iterative process where...

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A new approach for designing safer collision avoidance systems

Analytical workload model for estimating en route sector capacity in convective weather

June 14, 2011
  |
Conference Paper
Author:
John Y. Cho
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Published in:
9th USA/Europe Air Traffic Management Research and Development Sem., ATM 2011, 14-17 June 2011.
Topic:
air traffic control
R&D area:
R&D group:

Summary

We have extended an analytical workload model for estimating en route sector capacity to include the impact of convective weather. We use historical weather avoidance data to characterize weather blockage, which affects the sector workload in three ways: (1) Increase in the conflict resolution task rate via reduction in available airspace, (2) increase in the recurring task load through the rerouting of aircraft around weather, and (3) increase in the inter-sector coordination rate via reduction in the mean sector transit time. Application of the extended model to observed and forecast data shows promise for future use in network flow models.
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Summary

We have extended an analytical workload model for estimating en route sector capacity to include the impact of convective weather. We use historical weather avoidance data to characterize weather blockage, which affects the sector workload in three ways: (1) Increase in the conflict resolution task rate via reduction in available...

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Analytical workload model for estimating en route sector capacity in convective weather

Establishing a risk-based separation standard for unmanned aircraft self separation

June 14, 2011
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Conference Paper
Author:
Roland E. Weibel
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Published in:
9th USA/Europe Air Traffic Management Research and Development Sem., ATM 2011, 14-17 June 2011.
Topic:
collision avoidance
R&D area:
R&D group:

Summary

Unmanned Aircraft Systems require an ability to sense and avoid other air traffic to gain access to civil airspace and meet requirements in civil aviation regulations. One sense and avoid function is self separation, which requires that aircraft remain "well clear." An approach is proposed in this paper to treat well clear as a separation standard, thus posing it as a relative state between aircraft where the risk of collision first reaches an unacceptable level. By this approach, an analytically-derived boundary for well clear can be derived that supports rigorous safety assessment. A preliminary boundary is proposed in both time and distance for the well clear separation standard, and recommendations for future work are made.
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Summary

Unmanned Aircraft Systems require an ability to sense and avoid other air traffic to gain access to civil airspace and meet requirements in civil aviation regulations. One sense and avoid function is self separation, which requires that aircraft remain "well clear." An approach is proposed in this paper to treat...

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Establishing a risk-based separation standard for unmanned aircraft self separation

European and U.S. perspectives on the sharing and integration of weather information into ATM decisions

June 14, 2011
  |
Conference Paper
Author:
David Pace
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Published in:
ATM2011, 9th USA/Europe Air Traffic Management Research and Development Seminar, 14 June 2011.
Topic:
aviation weather
R&D area:
R&D group:

Summary

Weather is a major source of operational air traffic delays, accounting for 25 to 70 percent of all delays dependent of the geographical region. In today's Air Traffic Management (ATM) systems, a variety of weather information is available to help tactical and strategic planners better anticipate weather events that impact airspace capacity. Regretfully, the information is not always shared amongst all the stakeholders involved or well integrated into the existing ATM environment. This paper describes the high-level concepts for an improved sharing and integration or weather information into Air Traffic Management Decisions, as well as the current state and anticipated capabilities or the underlying information Management infrastructure.
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Summary

Weather is a major source of operational air traffic delays, accounting for 25 to 70 percent of all delays dependent of the geographical region. In today's Air Traffic Management (ATM) systems, a variety of weather information is available to help tactical and strategic planners better anticipate weather events that impact...

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European and U.S. perspectives on the sharing and integration of weather information into ATM decisions

Angle-and polarization-dependent collective excitation of plasmonic nanoarrays for surface enhanced infrared spectroscopy

June 6, 2011
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Journal Article
Author:
Vladimir Liberman
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Published in:
Opt. Express, Vol. 19, No. 12, 6 June 2011, 11202-11212.
Topic:
optics
R&D area:
R&D group:

Summary

Our recent work has showed that diffractively coupled nanoplasmonic arrays for Fourier transform infrared (FTIR) microspectroscopy can enhance the Amide I protein vibrational stretch by up to 105 times as compared to plain substrates. In this work we consider computationally the impact of a microscope objective illumination cone on array performance. We derive an approach for computing angular- and spatially-averaged reflectance for various numerical aperture (NA) objectives. We then use this approach to show that arrays that are perfectly optimized for normal incidence undergo significant response degradation even at modest NAs, whereas arrays that are slightly detuned from the perfect grating condition at normal incidence irradiation exhibit only a slight drop in performance when analyzed with a microscope objective. Our simulation results are in good agreement with microscope measurements of experimentally optimized periodic nanoplasmonic arrays.
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Summary

Our recent work has showed that diffractively coupled nanoplasmonic arrays for Fourier transform infrared (FTIR) microspectroscopy can enhance the Amide I protein vibrational stretch by up to 105 times as compared to plain substrates. In this work we consider computationally the impact of a microscope objective illumination cone on array...

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Angle-and polarization-dependent collective excitation of plasmonic nanoarrays for surface enhanced infrared spectroscopy

An active filter achieving 43.6dBm OIP3

June 5, 2011
  |
Conference Paper
Author:
Helen H. Kim
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Published in:
IEEE Radio Frequency Integrated Circuits Symp., RFIC, 5-7 June 2011.
Topic:
signal processing
R&D area:
R&D group:

Summary

An active filter with a 50 omega buffer suitable as an anti-alias filter to drive a highly linear ADC is implemented in 0.13 um SiGe BiCMOS. This 6th-order Chebyshev filter has a 3 dB cutoff frequency of 28.3 MHz and achieves 36.5 dBm OIP3. Nonlinear digital equalization further improves OIP3 to 43.6 dBm. Measurements show 92 dB of rejection at the stopband and a gain of 49 dB. The measured in-band OIP3 of 43.6 dBm is 19 dB higher than previously published designs.
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Summary

An active filter with a 50 omega buffer suitable as an anti-alias filter to drive a highly linear ADC is implemented in 0.13 um SiGe BiCMOS. This 6th-order Chebyshev filter has a 3 dB cutoff frequency of 28.3 MHz and achieves 36.5 dBm OIP3. Nonlinear digital equalization further improves OIP3...

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An active filter achieving 43.6dBm OIP3

Uses for field communication data in designing air traffic management decision support

May 31, 2011
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Conference Paper
Author:
Hayley J. Reynolds
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Published in:
10th Conf. on Naturalistic Decision Making, 31 May 2011.
Topic:
air traffic management
R&D area:
R&D group:

Summary

In this paper, example uses of field communication data are provided and how these data impact the evolution of the Route Availability Planning Tool (RAPT) for air traffic management is introduced. Simple communications analyses are provided that illustrate how communications can be used to improve what decision support is provided, who it is provided to, and in what context to present the support. Communications data is also shown to aid in contextualizing the decision support to better fit within the decision support framework in existence, which is critical to the success of situation awareness systems.
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Summary

In this paper, example uses of field communication data are provided and how these data impact the evolution of the Route Availability Planning Tool (RAPT) for air traffic management is introduced. Simple communications analyses are provided that illustrate how communications can be used to improve what decision support is provided...

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Uses for field communication data in designing air traffic management decision support

Convective weather avoidance modeling for low-altitude routes

May 31, 2011
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Project Report
Author:
Scot E. Campbell
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Published in:
MIT Lincoln Laboratory Report ATC-376
Topic:
weather
R&D area:
R&D group:

Summary

Thunderstorms are a leading cause of delay in the National Airspace System (NAS), and significant research has been conducted to predict the areas pilots will avoid during a storm. An example of such research is the Convective Weather Avoidance Model (CWAM), which provides the likelihood of pilot deviation due to convective weather in a given area. This report extends the scope of CWAM to include low-altitude flights, which typically occur below the tops of convective weather and have slightly differentoperational constraints. In general, the set of low-altitude flights include short-hop routes and low-altitude escape routes used to reduce the impact of convective weather in the termnial area. For classification, low altitude flights are identified as either deviations or non-deviations, and the corresponding weather features are analyzed. Precipitation intensity is observed to be the best predictor of deviation in the low-altitude flight regime, as compared to the differenc ein altitude between the flight and the echo tops for en route flights. Additionally, the low-altitude CWAM performs better than the departure CWAM currently used in the Route Availability Planning Tool (RAPT) when tested on deterministic weather data.
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Summary

Thunderstorms are a leading cause of delay in the National Airspace System (NAS), and significant research has been conducted to predict the areas pilots will avoid during a storm. An example of such research is the Convective Weather Avoidance Model (CWAM), which provides the likelihood of pilot deviation due to...

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Convective weather avoidance modeling for low-altitude routes

Estimation of potential IDRP benefits during convective weather SWAP

May 26, 2011
  |
Project Report
Author:
Richard A. DeLaura
…
Published in:
MIT Lincoln Laboratory Report ATC-381
Topic:
air traffic control
R&D area:
R&D group:

Summary

This document presents a preliminary analysis of potential departure delay reduction benefits in New York as the result of the use of the Integrated Departure Route Planning (IDRP) tool during convective severe weather avoidance programs (SWAP). The analysis is based on weather impact and air traffic data from operations between May and September 2010 in the New York metroplex region. Two methodologies were employed in the analysis: "flight pool" and "resource pool." In the flight pool methodology, individual flights with excessive taxi times were identified, and opportunities to find potential alternative reroutes using information that IDRP will provide were assessed. In the resource pool methodology, route impact minutes were tallied over several days, based on the judgment of a human analysis, and opportunities to recover capacity lost to route impacts via IDRP-identified reroutes were estimated. The flight pool methodology estimated that approximately 156 hours of delay could be saved through the use of IDRP over a full SWAP season. The resource pool methodology estimated that approximately 15% of capacity lost to convective weather impacts could be recovered via IDRP-based reroutes. It should be noted that the potential benefits are based on several assumptions that are described in detail in the text of the report. The estimation of delay savings due to reroute is also speculative. It is very difficult to ascertain when the assignment of a reroute actually makes use of underutilized capacity and when the reroute simply shifts the problem from one congested resource to another. Further research is needed to develop reliable metrics that can guide the assessment of reroute impacts on overall traffic management performance.
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Summary

This document presents a preliminary analysis of potential departure delay reduction benefits in New York as the result of the use of the Integrated Departure Route Planning (IDRP) tool during convective severe weather avoidance programs (SWAP). The analysis is based on weather impact and air traffic data from operations between...

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Estimation of potential IDRP benefits during convective weather SWAP

Making departure management weather impact models airspace-adaptable: adapting the New York Route Availability Planning Tool (RAPT) to Chicago departure airspace

May 26, 2011
  |
Project Report
Author:
Richard A. DeLaura
…
Published in:
MIT Lincoln Laboratory Report ATC-378
Topic:
air traffic control
R&D area:
R&D group:

Summary

The Route Availability Planning Tool (RAPT) operational prototype was deployed to Chicago in the summer of 2010, the first RAPT deployment outside of the New York departure airspace for which it was originally developed. The goal of the deployment was to evaluate the adaptability of RAPT's airspace definition, departure management and weather impact models to different terminal areas throughout the National Airspace System (NAS). This report presents the results of a summer-long evaluation of the Chicago RAPT operational prototype, in which the performance of RAPT algorithms and the effectiveness of the RAPT Concept of Operations were assessed. The evaluation included observations made by researchers simultaneously stationed at O'Hare terminal (ORD), the Chicago TRACON (C90), and the Chicago Air Route Traffic Control Center (ZAU) during several days of convective weather impact and post-event analysis of air traffic data from the Enhanced Traffic Management System (ETMS) and RAPT weather impact predictions and departure management guidance. The study found that significant departure delay reduction could be achieved through the use of RAPT in Chicago, and that RAPT effectiveness in "typical" corner post airspaces like Chicago could be further increased with some modifications to the Concept of Operations, user training, and site adaptation.
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Summary

The Route Availability Planning Tool (RAPT) operational prototype was deployed to Chicago in the summer of 2010, the first RAPT deployment outside of the New York departure airspace for which it was originally developed. The goal of the deployment was to evaluate the adaptability of RAPT's airspace definition, departure management...

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Making departure management weather impact models airspace-adaptable: adapting the New York Route Availability Planning Tool (RAPT) to Chicago departure airspace
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