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Initial validation of a convective weather avoidance model (CWAM) in departure airspace

October 16, 2011
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Conference Paper
Author:
Mikhail Rubnich
…
Published in:
DASC 2011, 30th IEEE/AIAA Digital Avionics Systems Conference, 16-20 October 2011, pp. 3A2.
Topic:
aviation weather
R&D area:
R&D group:

Summary

The Convective Weather Avoidance Model (CWAM) translates gridded, deterministic weather observations and forecasts into Weather Avoidance Fields (WAF). The WAF gives the probability, at each point in the grid, that a pilot will choose to deviate around convective weather at that location. CWAM have been developed and validated for en route, high altitude, level flight, low altitude level flight, and for descending arrivals. A heuristic CWAM for departures was also developed and deployed as part of the Route Availability Planning Tool (RAPT) prototype development in New York and Chicago. This paper presents an evaluation of the departure CWAM that is currently deployed as part of RAPT, based on an analysis of departure traffic in the Chicago terminal area during convective weather events.
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Summary

The Convective Weather Avoidance Model (CWAM) translates gridded, deterministic weather observations and forecasts into Weather Avoidance Fields (WAF). The WAF gives the probability, at each point in the grid, that a pilot will choose to deviate around convective weather at that location. CWAM have been developed and validated for en...

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Initial validation of a convective weather avoidance model (CWAM) in departure airspace

Estimating the likelihood of success in departure management strategies during convective weather

October 16, 2011
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Conference Paper
Author:
Richard A. DeLaura
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Published in:
Proc. 30th IEEE/AIAA Digital Avionics Systems Conference, DASC, 16-20 October 2011, pp. 6D4.
Topic:
aviation weather
R&D area:
R&D group:

Summary

The presence of convective weather (thunderstorms) in terminal and nearby en route airspace of major metroplex areas can have significant impacts on departure operations. Traffic on departure routes impacted by convective weather may be constrained by miles-in-trail (MIT) restrictions, to allow controllers the time needed to maneuver individual flights around thunderstorms that pilots wish to avoid. When the workload required to manage traffic flows becomes too great, departure routes may be closed. Departures still on the ground that are filed on closed or restricted routes may face significant delays as they wait for clearance on their filed route, or for a viable reroute to be implemented. The solution proposed in concepts such as the Integrated Departure Route Planning tool (IDRP) [1] is the use of weather and departure demand forecasts to plan and implement reroutes to avoid weather and volume congestion proactively, well in advance of route restrictions or closures.
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Summary

The presence of convective weather (thunderstorms) in terminal and nearby en route airspace of major metroplex areas can have significant impacts on departure operations. Traffic on departure routes impacted by convective weather may be constrained by miles-in-trail (MIT) restrictions, to allow controllers the time needed to maneuver individual flights around...

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Estimating the likelihood of success in departure management strategies during convective weather

Analysis of open-loop and closed-loop planning for aircraft collision avoidance

October 5, 2011
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Conference Paper
Author:
James P. Chryssanthacopoulos
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Published in:
2011 14th Int. IEEE Conf. on Intelligent Transportation Systems, 5-7 October 2011, pp. 212-217.
Topic:
collision avoidance
R&D area:
R&D group:

Summary

Open-loop planning has been a popular approach for developing aircraft collision avoidance systems. Open-loop planning computes a future plan to follow without anticipation of how future observations can affect the future course of action. Closed-loop planning, in contrast, takes into account the ability to react to future information. This paper explores trade-offs that exist between the two strategies as they apply to aircraft collision avoidance. It demonstrates some of the performance gains that con be realized by adopting a closed-loop planning strategy.
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Summary

Open-loop planning has been a popular approach for developing aircraft collision avoidance systems. Open-loop planning computes a future plan to follow without anticipation of how future observations can affect the future course of action. Closed-loop planning, in contrast, takes into account the ability to react to future information. This paper...

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Analysis of open-loop and closed-loop planning for aircraft collision avoidance

Dual polarization radar winter storm studies supporting development of NEXRAD-based aviation hazard products

September 29, 2011
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Conference Paper
Author:
Earle R. Williams
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Published in:
35th Conf. on Radar Meteorology, 26-30 September 2011.
Topic:
aviation weather
R&D area:
R&D group:

Summary

The Next Generation Weather Radar (NEXRAD) dual polarization upgrade has begun adding a functional enhancement to classify hydrometeors. MIT Lincoln Laboratory (LL) develops NEXRAD-based weather radar products for Federal Aviation Administration (FAA) weather systems such as Corridor Integrated Weather System (CIWS), Integrated Terminal Weather System (ITWS), and Weather and Radar Processor (WARP). Without dual polarization, those products are limited to providing information on precipitation location and intensity. With dual polarization, LL is now developing new aviation weather products to determine locations of hydrometeor-based hazards. A product for Icing Hazards Level (IHL) is expected to benefit the FAA. LL has partnered with Valparaiso University (VU) in northern Indiana near Chicago since 2008 to study the evolution of winter storms prior to the NEXRAD dual polarization upgrade. VU contributes to the study a C-band dual polarization weather radar, an on-demand local sounding capability, and a surface winter weather verification team. Additionally, the Wolcott, IN wind profiler is about 70 km south within viewing range of the VU radar, and provides information on the fall speeds of the hydrometeors of interest. This resource-rich location has allowed for substantive study of many winter storm types: synoptic, lake effect, and frontal passages. A key to development of the IHL product is the ability to interpret dual polarization radar signatures from the winter microphysical states and precipitation structures. Evolution of the structures is a response to the microphysical water and ice saturation (sub or super) states. The magnitude of the vertical lift may affect the saturation states. Methods to segregate the radar signatures will be important regarding the inferred presence of a supercooled water icing hazard. The blizzard of Feb. 1 and 2, 2011 produced four distinct precipitation periods (snow, sleet, freezing drizzle, and lake effect snow), all of which will be discussed. The paper and presentation will also detail findings from the study of multiple winter storms and how they inform the development of the IHL product.
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Summary

The Next Generation Weather Radar (NEXRAD) dual polarization upgrade has begun adding a functional enhancement to classify hydrometeors. MIT Lincoln Laboratory (LL) develops NEXRAD-based weather radar products for Federal Aviation Administration (FAA) weather systems such as Corridor Integrated Weather System (CIWS), Integrated Terminal Weather System (ITWS), and Weather and Radar...

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Dual polarization radar winter storm studies supporting development of NEXRAD-based aviation hazard products

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

September 20, 2011
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Conference Paper
Author:
Roland E. Weibel
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Published in:
11th AIAA Aviation Technology, Integration, and Operations (ATIO) Conf., 20-22 September 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

A field demonstration of the air traffic control Tower Flight Data Manager prototype

September 19, 2011
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Conference Paper
Author:
Hayley J. Reynolds
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Published in:
HFES 2011, Human Factors and Ergonomics Society 55th Annual Mtg., 19-23 September 2011, p. 61-65.
Topic:
air traffic control
R&D area:
R&D group:

Summary

The development and evaluation process of the Tower Flight Data Manager prototype at Dallas Ft. Worth airport is described. Key results from the first field evaluation are presented, including lessons learned about making electronic flight information acceptable to controllers. Iteration of the field evaluation methods are discussed for practitioner benefit.
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Summary

The development and evaluation process of the Tower Flight Data Manager prototype at Dallas Ft. Worth airport is described. Key results from the first field evaluation are presented, including lessons learned about making electronic flight information acceptable to controllers. Iteration of the field evaluation methods are discussed for practitioner benefit.

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A field demonstration of the air traffic control Tower Flight Data Manager prototype

Concept of operations for the Integrated Departure Route Planning (IDRP) tool

September 12, 2011
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Project Report
Author:
Hayley J. Reynolds
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Published in:
MIT Lincoln Laboratory Report ATC-379
Topic:
decision support
R&D area:
R&D group:

Summary

A concept of operations for the Integrated Departure Route Planner (IDRP) tool is proposed to address issues in the area of departure route management. By combining information about weather and departure demand, IDRP can both identify potential demand/capacity imbalances and recommend a rerouting option, if appropriate. To effectively implement IDRP into the operational environment, a twophase approach is suggested. The first phase appends IDRP functionality onto the CIWS/RAPT platform, combining departure demand information with the convective weather information, creating a live prototype. This initial phase allows a gradual introduction of functionality into an existing display and enables the gathering of operational data to appropriately evolve IDRP to phase 2. The second phase involves introducing airline route preferences, along with any operational improvements discovered during the initial phase.
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Summary

A concept of operations for the Integrated Departure Route Planner (IDRP) tool is proposed to address issues in the area of departure route management. By combining information about weather and departure demand, IDRP can both identify potential demand/capacity imbalances and recommend a rerouting option, if appropriate. To effectively implement IDRP...

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Concept of operations for the Integrated Departure Route Planning (IDRP) tool

Hazard alerting based on probabilistic models

August 8, 2011
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Conference Paper
Author:
James P. Chryssanthacopoulos
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Published in:
AIAA Modeling and Simulation Technologies Conf., 8-11 August 2011.
Topic:
air traffic control
R&D area:
R&D group:

Summary

Hazard alerting systems alert operators to potential future undesirable events so that action may be taken to mitigate risk. One way to develop a hazard alerting system based on probabilistic models is by using a threshold-based approach, where the probability of the undesirable event without mitigation is compared against a threshold. Another way to develop such a system is to model the system as a Markov decision process and solve for the hazard alerting strategy that maximizes expected utility. This paper analyzes and compares these two methods. The experiments reveal that an expected utility approach performs better than threshold-based approaches when the dynamic stochasticity is high, where accounting for delays or changes in the alert becomes more important. However, for certain system parameters and operating environments, a threshold-based approach may provide comparable performance.
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Summary

Hazard alerting systems alert operators to potential future undesirable events so that action may be taken to mitigate risk. One way to develop a hazard alerting system based on probabilistic models is by using a threshold-based approach, where the probability of the undesirable event without mitigation is compared against a...

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Hazard alerting based on probabilistic models

Convective weather avoidance modeling in low-altitude airspace

August 8, 2011
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Conference Paper
Author:
Scot E. Campbell
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Published in:
AIAA Modeling and Simulation Technologies Conf., 8-11 August 2011.
Topic:
aviation 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 paper extends the scope of CWAM to include low-altitude flights, which typically occur below the tops of convective weather and have slightly different operational constraints. In general, the set of low-altitude flights includes short-hop routes and low-altitude escape routes used to reduce the impact of convective weather in the terminal area. This paper will discuss the classification procedure, present the performance of low-altitude CWAM on observed and forecasted weather, analyze areas of poor performance, and suggest potential improvements to the model.
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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 in low-altitude airspace

Update on COSPA storm forecasts

August 2, 2011
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Conference Paper
Author:
Haig Iskenderian
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Published in:
15th Conf. on Aviation, Range and Aerospace Meteorology, 1-4 August 2011.
Topic:
aviation weather
R&D area:
R&D group:

Summary

Air traffic congestion in the United States (US) is a serious national problem resulting in a critical need for timely, reliable and high quality forecasts of precipitation and echo tops with forecast time horizons of up to 8 hours. In order to address the short-term needs of the Federal Aviation Administration (FAA) as well as the long-term goals of the US's Next Generation Airspace System (NextGen), MIT Lincoln Laboratory, NCAR Research Applications Laboratory and NOAA Earth Systems Research Laboratory (ESRL) Global Systems Division (GSD) are collaborating on developing a forecast system under funding from the FAA's Aviation Weather Research Program (AWRP). The CoSPA system combines the latest technologies in heuristic nowcasting, extrapolation, statistical techniques and numerical weather prediction to produce rapidly updating (15 min) 0-8 hour forecasts of storm locations, echo tops and intensities. The system blends highly-skillful heuristic nowcasts with output from NOAA's High Resolution Rapid Refresh (HRRR) using phase correction and statistical weighting functions. The CoSPA 0-8 hour forecasts are accessible to the aviation community via an operational situation display and a website that builds upon the FAA's Corridor Integrated Weather System (CIWS) and shows current time situational awareness products including: VIL, echo tops, lightning, growth and decay, forecasts and verification contours, as well as an animation of the weather from 8 hours in the past to 8 hours into the future. This presentation will include a brief description of the CoSPA forecast system and display, examples of forecast performance, and provide an overview of recent enhancements to CoSPA as well as ongoing research.
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Summary

Air traffic congestion in the United States (US) is a serious national problem resulting in a critical need for timely, reliable and high quality forecasts of precipitation and echo tops with forecast time horizons of up to 8 hours. In order to address the short-term needs of the Federal Aviation...

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Update on COSPA storm forecasts
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