Publications
Initial studies of an objective model to forecast achievable airspace flow program throughput from current and forecast weather information
December 11, 2008
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-343
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Summary
Airspace capacity constraints caused by adverse weather are a major driver for enhanced Traffic Flow Management (TFM) capabilities. One of the most prominent TFM initiatives introduced in recent years is the Airspace Flow Program (AFP). AFPs are used to plan and manage flights through airspace constrained by severe weather. An AFP is deployed using "strategic" (i.e., 4-6 hour) weather forecasts to determine AFP traffic throughput rates. These rates are set for hourly periods. However, as convective weather continuously evolves, the achievable en route airspace throughput can fluctuate significantly over periods as short as 15-30 minutes. Thus, without tactical AFP adjustments, inefficiencies in available airspace usage can arise, often resulting in increased air traffic delay. An analysis of AFP usage in 2007 was conducted in order to (1) better understand the relationship between AFP parameters and convective weather characteristics, and (2) assess the potential use of an objective model for forecasting tactical AFP throughput. An en route airway blockage-based algorithm, using tactical forecast information from the Corridor Integrated Weather System (CIWS), has been developed in order to objectively forecast achievable flow rates through AFP boundaries during convective weather. A description of the model and preliminary model results are presented.
Summary
Airspace capacity constraints caused by adverse weather are a major driver for enhanced Traffic Flow Management (TFM) capabilities. One of the most prominent TFM initiatives introduced in recent years is the Airspace Flow Program (AFP). AFPs are used to plan and manage flights through airspace constrained by severe weather. An...
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Operational usage of the Route Availability Planning Tool during the 2007 convective weather season : executive summary
October 6, 2008
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-339-1
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The Route Availability Planning Tool (RAPT) is an integrated weather/air traffic management decision support tool that has been designed to help traffic managers better anticipate weather impacts on jet routes and thus improve NY departure route usage efficiency. A field study was conducted in 2007 to evaluate RAPT technical performance at forecasting route blockage, to assess RAPT operational use during adverse weather, and to evaluate RAPT benefits. The operational test found that RAPT guidance was operationally sound and timely in many circumstances. RAPT applications included increased departure route throughput, more efficient reroute planning, and more timely decision coordination. Estimated annual NY departure delay savings attributed to RAPT in 2007 totaled 2,300 hours, with a cost savings of $7.5 M. The RAPT field study also sought to develop a better understanding of NY traffic flow decision-making during convective weather impacts since the RAPT benefi ts in 2007 were significantly limited by a number of factors other than direct weather impacts. Observations were made of the multi-facility departure management decision chain, the traffic management concerns and responsibilities at specific FAA facilities, and the procedures and pitfalls of the current process for capturing and disseminating key information such as route/fix availability and restrictions.
Summary
The Route Availability Planning Tool (RAPT) is an integrated weather/air traffic management decision support tool that has been designed to help traffic managers better anticipate weather impacts on jet routes and thus improve NY departure route usage efficiency. A field study was conducted in 2007 to evaluate RAPT technical performance...
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Operational usage of the Route Availability Planning Tool during the 2007 convective weather season
October 6, 2008
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-339
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Summary
The Route Availability Planning Tool (RAPT) is an integrated weather/air traffic management decision support tool that has been designed to help traffic managers better anticipate weather impacts on jet routes and thus improve NY departure route usage efficiency. A field study was conducted in 2007 to evaluate RAPT technical performance at forecasting route blockage, to assess RAPT operational use during adverse weather, and to evaluate RAPT benefits. The operational test found that RAPT guidance was operationally sound and timely in many circumstances. RAPT applications included increased departure route throughput, more efficient reroute planning, and more timely decision coordination. Estimated annual NY departure delay savings attributed to RAPT in 2007 totaled 2,300 hours, with a cost savings of $7.5 M. The RAPT field study also sought to develop a better understanding of NY traffic flow decision-making during convective weather impacts since the RAPT benefits in 2007 were significantly limited by a number of factors other than direct weather impacts. Observations were made of the multi-facility departure management decision chain, the traffic management concerns and responsibilities at specific FAA facilities, and the procedures and pitfalls of the current process for capturing and disseminating key information such as route/fix availability and restrictions.
Summary
The Route Availability Planning Tool (RAPT) is an integrated weather/air traffic management decision support tool that has been designed to help traffic managers better anticipate weather impacts on jet routes and thus improve NY departure route usage efficiency. A field study was conducted in 2007 to evaluate RAPT technical performance...
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Measuring the uncertainty of weather forecasts specific to air traffic management operations
August 4, 2008
Conference Paper
Published in:
89th ARAM Special Symp., 4 August 2008.
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In this paper, we develop a novel way to measure the accuracy of weather forecasts based upon the impact on air traffic flows. This method uses new techniques developed as part of the CWAM that consider the complicated interaction between pilots, air traffic controllers and weather. This technique, known as the blockage model (Martin et al., 2006), differentiates between minor deviations performed by pilots around convective weather and their larger deviations due to fully blocked air routes that require air traffic control interaction. This blockage model is being used by the automated Route Availability Planning Tool (RAPT) to predict route blockage for NYC departures. RAPT integrates the Corridor Integrated Weather Systems (CIWS) deterministic 0-2 hour forecasts of precipitation and echo tops into route specific forecasts of impact on air traffic in the congested east coast corridor. Applying the blockage model to the entire CIWS weather domain as a metric for scoring the performance of the forecast algorithms is shown to be an excellent approach for measuring the adequacy of the forecast in predicting the impact of the convective weather on air traffic operations.
Summary
In this paper, we develop a novel way to measure the accuracy of weather forecasts based upon the impact on air traffic flows. This method uses new techniques developed as part of the CWAM that consider the complicated interaction between pilots, air traffic controllers and weather. This technique, known as...
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Modeling convective weather avoidance in enroute airspace
January 20, 2008
Conference Paper
Published in:
13th Conf. on Aviation, Range and Aerospace Meteorology, ARAM, 20-24 January 2008.
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It is generally agreed that effective management of convective weather in congested airspace requires decision support tools that translate the weather products and forecasts into forecasts of ATC impacts and then use those ATC impact forecasts to suggest air traffic management strategies. In future trajectory-based operations, it will be necessary to automatically generate flight trajectories through or around convective weather that pilots will find acceptable. A critical first step, needed in both today's air traffic management environment and in the highly automated systems of the future, is a validated model for airspace that pilots will seek to avoid. At the 12th Conference on Aviation, Range and Aerospace Meteorology (Atlanta, 2006), we reported on an initial Convective Weather Avoidance Model (CWAM1) (DeLaura and Evans; 2006). The CWAM1 outputs are three dimensional deterministic and probabilistic weather avoidance fields (WAFs). CWAM1 used Corridor Integrated Weather System (CIWS) VIL and echo top fields and National Lightning Detection Network (NLDN) data to predict aircraft deviations and penetration. CWAM1 was developed using more than 500 aircraft-convective weather encounters in the Indianapolis Air Route Traffic Control Center (ZID ARTCC) airspace. CWAM1 gave the greatest weight to the difference between flight altitude and the 18 dbZ radar echo top with precipitation intensity playing a secondary role. The deviation prediction error rate in CWAM1 was approximately 25%. This paper presents a new model (CWAM2), based on the analysis of trajectories from several ARTCCs [Indianapolis (ZID), Cleveland (ZOB) and meteorological deviation predictors. Additional weather factors that are considered include vertical storm structure (upper level reflectivity and the height of the VIL centroid derived from the NSSL 3D reflectivity mosaic), vertical and horizontal storm growth, the spatial variation in VIL and echo top fields and storm motion.
Summary
It is generally agreed that effective management of convective weather in congested airspace requires decision support tools that translate the weather products and forecasts into forecasts of ATC impacts and then use those ATC impact forecasts to suggest air traffic management strategies. In future trajectory-based operations, it will be necessary...
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Key research issues for near term operational use of integrated convective weather-ATM decision support systems
January 20, 2008
Conference Paper
Published in:
13th Conf. on Aviation, Range and Aerospace Meteorology, ARAM, 20-24 January 2008.
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Thunderstorm-related delays dominate the overall U.S. airspace delay statistics and continue to increase, even though a number of new weather information systems and air traffic management (ATM) decision support tools have been deployed since 1999. Operational decision makers must mitigate the network congestion that arises from rapidly varying capacity loss in both en route and terminal airspace. Improving decision making in such an environment requires explicitly considering airspace structure, network impacts, forecast uncertainty and pilot preferences for weather avoidance. To date, the NextGen initiative has focused on envisioning an operational concept and research agenda for 2025 where it is assumed that aircraft separation and weather avoidance is accomplished using a high degree of automation. In this paper, we consider research to achieve significant improvements in the near term (2010-2015) where aircraft separation is provided largely by controllers and hazardous weather avoidance is accomplished by pilots using visual cues, reports from other aircraft, on board weather radar and ATC advisories. We briefly review the current status of work in key areas and then suggest major near term initiatives. Key elements of the research program to be discussed include: 1. Translation of convective weather products into ATC impacts (including handling of uncertainty in the convective weather forecasts). Initial models for en route pilot avoidance of storms and sector capacity in convective weather have shown promising results, but clearly much more research is needed in this area. 2. Determining when and where available capacity was not appropriately utilized during convective events, based on both facility observations during storm events and computations of avoidable delay. Preliminary results suggest that much of today's delay is in fact avoidable. 3. Developing integrated weather-ATM decision support tools (DST) to enable decision makers to more fully utilize available capacity. The accuracy of contemporary convective weather forecasts is a key issue in the design of such systems. Initial operational experience with a departure decision support tool will be discussed to illustrate key points. 4. Explicitly considering the human side of convective weather ATM [e.g., how individuals make real time decisions in collaboration with other decision makers (e.g., ATC, airlines, dispatch, pilots)]. Recent results from field usage of convective weather decision support tools will be interpreted in the context of recent literature on how people actually make decisions and perform cognitively complex functions in demanding situations.
Summary
Thunderstorm-related delays dominate the overall U.S. airspace delay statistics and continue to increase, even though a number of new weather information systems and air traffic management (ATM) decision support tools have been deployed since 1999. Operational decision makers must mitigate the network congestion that arises from rapidly varying capacity loss...
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Measuring the utilization of available aviation system capacity in convective weather
January 20, 2008
Conference Paper
Published in:
13th Conf. on Aviation, Range and Aerospace Meteorology, ARAM, 20-24 January 2008.
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There is currently great interest in improving the ability to quantitatively assess how well U.S. Air Traffic Control (ATC) services are being provided as new weather-air traffic management (ATM) decision support capabilities are added. One of the three proposed metrics currently under study by the Federal Aviation Administration (FAA) and airlines is resource utilization, which has been defined as "the safe and efficient use of available airport or airspace capacity." Measurement of capacity utilization is particularly difficult during convective weather since storms cause capacity reductions in both en route and terminal airspace. In particular, en route capacity loss results in network congestion that cannot be readily characterized by scalar metrics. This paper proposes the use of (i) models for translating 3-D weather radar data into time-varying estimates of the capacity reductions in affected en route sectors, terminal airspace, and airports, together with (ii) automatically-generated, broad-area ATM strategies that utilize the time-varying estimates of airspace capacity and demand to determine optimal reroute strategies or, when necessary, minimally disruptive ground or airborne delay programs to assess how the available capacity could best been utilized. By comparing actual vs. optimal capacity utilization, one can assess how effective the actual weather-ATM system was at utilizing the available capacity. Examples of applying this methodology to severe convective weather events from 2005 and 2006 will be presented.
Summary
There is currently great interest in improving the ability to quantitatively assess how well U.S. Air Traffic Control (ATC) services are being provided as new weather-air traffic management (ATM) decision support capabilities are added. One of the three proposed metrics currently under study by the Federal Aviation Administration (FAA) and...
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Air traffic management decision support during convective weather
June 1, 2007
Journal Article
Published in:
Lincoln Laboratory Journal, Vol. 16, No. 2, June 2007, pp. 263-276.
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Flight delays caused by thunderstorms are a significant and growing problem for airlines and the flying public. Thunderstorms disrupt the structured, preplanned flight routing and control process that is used to handle dense air traffic streams in congested airspace. Today's coping strategies are developed by traffic flow management (TFM) specialists who interpret weather measurements and forecasts to develop delay and rerouting strategies. The effectiveness of these strategies is limited by the lack of quantitative models for the capacity impacts of thunderstorms, and by the difficulty of developing and executing timely response strategies during rapidly changing convective weather. In this article, we describe initial work to develop more effective response strategies. We first review insights gained during operational testing of a simple but highly effective Route Availability Planning Tool that can significantly reduce convective-weather induced departure delays at congested airports. We then discuss work to develop core technical capabilities and applications that address broader TFM problems, including en route congestion. Objective models for airspace capacity reductions caused by thunderstorms are discussed, as is an associated scheduling algorithm that exploits the capacity estimates to develop broad-area TFM strategies that minimize delay. We conclude by discussing candidate real-time applications and airspace system performance analysis that is enabled by our weather-capacity models and optimal scheduling algorithm.
Summary
Flight delays caused by thunderstorms are a significant and growing problem for airlines and the flying public. Thunderstorms disrupt the structured, preplanned flight routing and control process that is used to handle dense air traffic streams in congested airspace. Today's coping strategies are developed by traffic flow management (TFM) specialists...
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Improving air traffic management group decision-making during severe convective weather
June 1, 2007
Conference Paper
Published in:
11th World Conf. on Transport Research, June 2007.
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There is an urgent need to enhance the efficiency of United States (U.S.) air traffic management (ATM) decision-making when convective weather occurs. Thunderstorm ATM decisions must be made under considerable time pressure with inadequate information (e.g., missing or ambiguous), high stakes, and poorly defined procedures. Often, multiple decisions are considered simultaneously; each requiring coordination amongst a heterogeneous set of decision-makers. Recent operational experience in the use of improved convective weather decision support systems in the Northeast quadrant of the U.S. is reviewed in the context of literature on individual and team decision-making in complex environments. Promising areas of research are identified.
Summary
There is an urgent need to enhance the efficiency of United States (U.S.) air traffic management (ATM) decision-making when convective weather occurs. Thunderstorm ATM decisions must be made under considerable time pressure with inadequate information (e.g., missing or ambiguous), high stakes, and poorly defined procedures. Often, multiple decisions are considered...
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Analysis of operational alternatives to the Terminal Doppler Weather Radar (TDWR)
February 26, 2007
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-332
Summary
Possible alternatives to the Terminal Doppler Weather Radar (TDWR) are assessed. We consider both the low altitude wind shear detection service provided by TDWR and its role in reducing weather-related airport delays through its input to the Integrated Terminal Weather System (ITWS). Airborne predictive wind shear (PWS) radars do not provide the broad area situational awareness needed to proactively reroute aircraft away from the affected runways. We considered in detail the alternative of using the ASR-9 Weather Systems Processor (WSP) and NEXRAD in lieu of TDWR. An objective metric for wind shear detection capability was calculated for each of these radars at all TDWR equipped airports. TDWR was uniformly superior by this metric, and at a number of the airports, the ASR-9/NEXRAD alternative scored so low as to raise questions whether it would be operationally acceptable. To assess airport weather delay reduction impact, we compared the accuracy of the high-benefit ITWS "Terminal Winds" product with and without TDWR input. Removal of the TDWR data would have increased the mean estimate error by a factor of 3 near the surface.
Summary
Possible alternatives to the Terminal Doppler Weather Radar (TDWR) are assessed. We consider both the low altitude wind shear detection service provided by TDWR and its role in reducing weather-related airport delays through its input to the Integrated Terminal Weather System (ITWS). Airborne predictive wind shear (PWS) radars do not...
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