Publications
Comparing convective weather avoidance models and aircraft-based data
August 4, 2008
Conference Paper
Published in:
89th ARAM Special Symp., 4 August 2008.
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Summary
The Convective Weather Avoidance Model (CWAM), developed in collaboration with NASA, translates convective weather information into a Weather Avoidance Field (WAF), to determine if pilots will route around convective regions. The WAF provides an estimate of the probability of pilot deviation around convective weather in en route airspace as a function of time, horizontal location, and flight altitude [1][2]. The results of the WAF can used to create reroutes around regions of convective weather where pilots are more likely to deviate. If reliable WAF information is provided to the cockpit and ground, pilot decisions may become more predictable, simplifying the task of air traffic control in convective weather. The improvement and validation of CWAM requires inference of pilot intent from flight trajectory data, which is challenging. The process currently involves laborious human review of the results of automated deviation detection algorithms. Both previous CWAM studies and a recent validation study [3] illustrate the difficulties and limitations of attempting to infer pilot intent from flight trajectory data. Furthermore, observed flight tracks may not correctly represent pilot preference. In some instances, pilots may have penetrated airspace that they would rather have avoided or they may have avoided airspace that was easily passable. In order to improve and assess the accuracy of the WAF, it is desirable to compare WAF predictions of pilot intent with direct evidence of the airborne experience during weather encounters in en route airspace, such as normal acceleration. To achieve this, a series of flights using a research aircraft was conducted. In the summer of 2008, four research flights (three on 17 July and one on 14 August) were flown in and around convective activity in the upper Midwestern United States to gather aircraft data that could be correlated to the WAF and other remotely-sensed weather data. The aircraft, a Rockwell Sabreliner Model 50 research aircraft (similar to the Sabreliner Model 40 production model) owned by Rockwell-Collins, flew through and around convective activity while recording on-board accelerations for comparison to the WAF deviation probabilities encountered along the flight trajectory. Aircraft state data, on-board weather radar images, video, photographs and pilot narrative from the cockpit were also collected. This paper briefly describes the CWAM model and WAF. Description of the data collection methodology is then presented. Following that section are descriptions of the flights comparing radar data from the flight deck with ground-based weather radar and the WAF. Visual observations and pilot narrative from the flight deck are also presented. Next, the normal acceleration data from on-board accelerometer data are compared with WAF. Finally, conclusions and suggestions for further study are presented.
Summary
The Convective Weather Avoidance Model (CWAM), developed in collaboration with NASA, translates convective weather information into a Weather Avoidance Field (WAF), to determine if pilots will route around convective regions. The WAF provides an estimate of the probability of pilot deviation around convective weather in en route airspace as a...
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Improving convective weather operations in highly congested airspace with the Corridor Integrated Weather System (CIWS)
October 4, 2004
Conference Paper
Published in:
11th Conf. on Aviation, Range and Aerospace Meteorology, 4-8 October 2004.
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Summary
Reducing thunderstorm-related air traffic delays in congested airspace has become a major objective of the FAA, especially given the recent growth in convective delays. In 2000 and 2001, the key new initiative for reducing these convective weather delays was "strategic" traffic flow management (TFM). Users were given 2-, 4-, and 6-hour collaborative convective weather forecasts, and collaborative traffic routing plans were established via telecons attended by Air Traffic Control (ATC) and airline traffic managers. This "strategic" approach led to difficulties during a large fraction of the weather events because it was not possible to generate forecasts of convective weather at time horizons between 2 and 6 hours that were accurate enough to assess impacts on routes and capacity, and thereby accomplish effective TFM. During convective weather events, traffic managers tend to focus on tactical TFM [Huberdeau, 2004], yet they had relatively inaccurate current weather information and tactical forecasts. The Corridor Integrated Weather System (CIWS) demonstration began in 2001. The objectives of the demonstration are to provide improved tactical air traffic management (ATM) decision support, via improved real time 3D products and accurate short-term convective weather forecasts, and to determine if this support is an operationally useful complement to "strategic" TFM. The current focus of the CIWS initiative is the highly congested airspace containing the Great Lakes and Northeast corridors, since that region offers the greatest potential for delay reduction benefits. In this paper, we describe the current status of CIWS, including initial operational results of Air Traffic Control (ATC) and airline use of the CIWS weather products. We begin with some CIWS background, describing the motivation for the program, the role of CIWS products in the overall convective weather planning process, and the functional domains in which CIWS products can provide operationally significant benefits. We then review the current CIWS capabilities, spatial coverage, sensors used, products, operational users, and integration with ATM systems. Next the detailed CIWS operational benefits study carried out in 2003 is summarized. Finally, we discuss the FAA plans for CIWS and near term enhancements to the system.
Summary
Reducing thunderstorm-related air traffic delays in congested airspace has become a major objective of the FAA, especially given the recent growth in convective delays. In 2000 and 2001, the key new initiative for reducing these convective weather delays was "strategic" traffic flow management (TFM). Users were given 2-, 4-, and...
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Corridor integrated weather system operation benefits 2002-2003 : initial estimates of convective weather delay reduction : executive summary
May 19, 2004
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-313-1
Summary
The Corridor Integrated Weather System (CIWS) seeks to improve safety and reduce delay by providing accurate, automated, rapidly updated information on storm locations and echo tops along with two-hour high-resolution animated growth and decay convective storm forecasts. An operational benefits assessment was conducted using on-site observations of CIWS usage at major en route control centers in the Northeast and Great Lakes corridors and the Air Traffic Control Systems Command Center (ATCSCC) during six multi-day periods in 2003. (Not complete).
Summary
The Corridor Integrated Weather System (CIWS) seeks to improve safety and reduce delay by providing accurate, automated, rapidly updated information on storm locations and echo tops along with two-hour high-resolution animated growth and decay convective storm forecasts. An operational benefits assessment was conducted using on-site observations of CIWS usage at...
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Corridor Integrated Weather System operation benefits 2002-2003 : initial estimates of convective weather delay reduction
April 9, 2004
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-313
Summary
The Corridor Integrated Weather System (CIWS) seeks to improve safety and reduce delay by providing accurate, automated, rapidly updated information on storm locations and echo tops along with two-hour high-resolution animated growth and decay convective storm forecasts. An operational benefits assessment was conducted using on-site observations of CIWS usage at major en route control centers in the Northeast and Great Lakes corridors and the Air Traffic Control Systems Command Center (ATCSCC) during six multi-day periods in 2003. This first phase of the benefit assessment characterizes major safety and delay reduction benefits and quantifies the delay reduction benefits for two key Traffic Flow Management (TFM) user benefits: "keeping air routes open longer/reopening closed routes soon" and "proactive, efficient reroutes of traffic around storm cells." The overall CIWS delay reduction for these two benefits is 40,000 to 69,000 hours annually with an equivalent monetary value ot $127M to $26M annually. Convective weather delays at most of the major airports in the test domain, normalized by thunderstorm frequency, decreased after new CIWS echo tops and forecast products were introduced. Recommendations are made for near-term, low-cost improvements to the CIWS demonstration system to further increase the operational benefits.
Summary
The Corridor Integrated Weather System (CIWS) seeks to improve safety and reduce delay by providing accurate, automated, rapidly updated information on storm locations and echo tops along with two-hour high-resolution animated growth and decay convective storm forecasts. An operational benefits assessment was conducted using on-site observations of CIWS usage at...
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An examination of wind shear alert integration at the Dallas/Ft. Worth International Airport (DFW)
August 20, 2003
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-309
Summary
The Dallas / Fort Worth International Airport (DFW) is one of the four demonstration system sites for the Integrated Terminal Weather System (ITWS). One of the primary benefits of the ITWS is a suite of algorithms that utilize data from the Terminal Doppler Weather Radar (TDWR) to generate wind shear alerts. DFW also benefits from a Network Expansion of the Low-Level Wind Shear Advisory System (LLWAS-NE). The LLWAS-NE generated alerts are integrated with the radar-based alerts in ITWS to provide Air Traffic Control (ATC) with a comprehensive set of alert information. This study examines the integrated DFW wind shear alerts with emphasis on circumstances in which the detection performance of the TDWR-based wind shear algorithms was poor. Specific detection problems occur in the following situations: when wind shear events over the airport are aligned along a radial to the TDWR, during "non-traditional" wind shear events, when severe signal attenuation occurs during heavy precipitation over the TDWR radar site, and because of excessive TDWR clutter-residue editing over the airport. In all of the cases examined, the LLWAS-NE issued alerts to ATC that would have otherwise gone unreported.
Summary
The Dallas / Fort Worth International Airport (DFW) is one of the four demonstration system sites for the Integrated Terminal Weather System (ITWS). One of the primary benefits of the ITWS is a suite of algorithms that utilize data from the Terminal Doppler Weather Radar (TDWR) to generate wind shear...
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Reducing severe weather delays in congested airspace with weather decision support for tactical air traffic management
June 23, 2003
Conference Paper
Published in:
5th Eurocontrol/DAA ATM R&D Seminar, 23-27 June 2003.
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Summary
Reducing congested airspace delays due to thunderstorms has become a major objective of the FAA due to the recent growth in convective delays. In 2000 and 2001 the key new initiative for reducing these convective weather delays was "strategic" traffic flow management (TFM) at time scales between 2 and 6 hours in advance using collaborative weather forecasts and routing strategy development. This "strategic" approach experienced difficulties in a large fraction of the weather events because it was not possible to forecast convective storm impacts on routes and capacities accurately enough to accomplish effective traffic flow management. Hence, we proposed in 2001 that there needed to be much greater emphasis on tactical air traffic management at time scales where it would be possible to generate much more accurate convective weather forecasts. In this paper, we describe initial operational results in the very highly congested Great Lakes and Northeast Corridors using weather products from the ongoing Corridor Integrated Weather System (CIWS) concept exploration. Key new capabilities provided by this system include very high update rates (to support tactical air traffic control), much improved echo-tops information, and fully automatic 2-hour convective forecasts using the latest "scale separation" storm tracking technologies. Displays were provided at major terminal areas, en route centers in the corridors, and the FAA Command Center. Substantial reduction in delays has been achieved mostly through weather product usage at the shorter time scales. Quantifying the achieved benefits for this class of products have raised major questions about the conceptual framework for traffic flow management in these congested corridors that must be addressed in the development of air traffic management systems to utilize the weather products.
Summary
Reducing congested airspace delays due to thunderstorms has become a major objective of the FAA due to the recent growth in convective delays. In 2000 and 2001 the key new initiative for reducing these convective weather delays was "strategic" traffic flow management (TFM) at time scales between 2 and 6...
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Multi-radar integration to improve en route aviation operations in severe convective weather
February 12, 2003
Conference Paper
Published in:
19th Int. Conf. of Interactive Info Processing Systems in Meteorology, Oceanography and Hydrology, IIPS, 9-13 February 2003.
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Summary
In this paper, we describe a major new FAA initiative, the Corridor Integrated Weather System (CIWS), to improve convective weather decision support for congested en route airspace and the terminals within that airspace through use of a large, heterogeneous network of weather sensing radars as well as many additional sensors. The objective of the CIWS concept exploration is to determine the improvements in NAS performance that could be achieved by providing en route controllers, en route and major terminal traffic flow managers, and airline dispatch with accurate, fully automated high update-rate information on current and near term (0-2 hour) storm locations, severity and vertical structure so that they can achieve more efficient tactical use of the airspace. These "tactical" traffic flow management products will complement the longer-term (2-6 hr) forecasts that are also needed for flight planning and strategic traffic flow management. Since balancing the en route traffic flows in the presence of time varying impacts on sector capacities by convective weather is essential if delays are to be reduced, an important element of the CIWS initiative is interfacing to and, in some cases providing, air traffic flow management (TFM) and airline dispatch decision support tools (DSTs)
Summary
In this paper, we describe a major new FAA initiative, the Corridor Integrated Weather System (CIWS), to improve convective weather decision support for congested en route airspace and the terminals within that airspace through use of a large, heterogeneous network of weather sensing radars as well as many additional sensors...
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En route weather depiction benefits of the NEXRAD vertically integrated liquid water product utilized by the Corridor Integrated Weather System
May 13, 2002
Conference Paper
Published in:
10th Conf. on Aviation, Range, and Aerospace Meteorology, 13-16 May 2002, pp. 120-123.
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Summary
It is demonstrated in this paper that weather depictions in an operational environment based upon VIL provide more meaningful information for en route traffic routing than a BREF product. VIL precipitation proves advantageous in limiting contamination from Anomalous Propagation (AP) ground clutter, biological targets (e.g., birds and insects), and radar artifacts. The extended vertical coverage of VIL sampling also better depicts storm cells as they first develop, further assisting traffic managers achieve more efficient use of tactical airspace when weather occurs unexpectedly.
Summary
It is demonstrated in this paper that weather depictions in an operational environment based upon VIL provide more meaningful information for en route traffic routing than a BREF product. VIL precipitation proves advantageous in limiting contamination from Anomalous Propagation (AP) ground clutter, biological targets (e.g., birds and insects), and radar...
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Operational Experience with TDWR/LLWAS-NE Integration at the Dallas, TX International Airport (DFW)
May 13, 2002
Conference Paper
Published in:
10th Conf. on Aviation, Range and Aerospace Meteorology, 13-16 May 2002, pp. 391-394.
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Summary
At nine major airports, both the Terminal Doppler Weather Radar (TDWR) and Network Extension of the Low-Level Wind shear Advisory System (LLWAS-NE) data will be used to detect and warn Air Traffic Control (ATC) of dangerous wind shear conditions. The integration of wind shear alerts from the two systems is currently being carried out by the TDWR software and will be accomplished by Integrated Terminal Weather System (ITWS) software when the ITWS is installed at these airports. Previous studies of the performance of the TDWR/LLWAS-NE integrated system were carried out at Denver, CO, Dallas, and Orlando, FL. Additionally, there have been recent concerns about false alarms with the LLWAS-NE. In this study, we examine the performance of the integrated system at Dallas-Ft. Worth International Airport (DFW) over a 6-month period in 2000 with particular emphasis on integrated wind shear alerts produced during a number of cases where the TDWR had difficulty making detections due to: 1. radially aligned gust fronts over DFW, 2. radially aligned divergent features, divergence behind gust fronts and divergence embedded within gravity waves, and/or 3. TDWR radome attenuation or excessively aggressive clutter residue editing. DFW is a particularly good airport for such a study because there is an additional TDWR [for Dallas Love airport (DAL)] located in close proximity to DFW and situated in such a way that it provides a very good viewing angle for wind shear events that may not be well characterized by the DFW TDWR radial velocity data. DFW is also an ITWS demonstration system test site with trained meteorologists who review the wind shear detection performance after all convective weather events at DFW.
Summary
At nine major airports, both the Terminal Doppler Weather Radar (TDWR) and Network Extension of the Low-Level Wind shear Advisory System (LLWAS-NE) data will be used to detect and warn Air Traffic Control (ATC) of dangerous wind shear conditions. The integration of wind shear alerts from the two systems is...
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Developing a mosiacked gust front detection algorithm for TRACONS with multiple TDWRS
September 11, 2000
Conference Paper
Published in:
Proc. Ninth Conf. on Aviation, Range, and Aerospace Meteorology, 11-15 September 2000, pp. 494-498.
Summary
Gust front detection is an important Initial Operational Capability (IOC) of the Integrated Terminal Weather System (ITWS). The Machine Intelligent Gust Front Algorithm (MIGFA) being deployed for ITWS uses multi-dimensional, knowledge-based signal processing techniques to detect and track gust fronts in Terminal Doppler Weather Radar (TDWR) data. Versions of MIGFA have also been developed for the ASR-9 Weather Systems Processor (WSP) and NEXRAD, and within the past year MIGFA was installed as the primary gust front detection algorithm for operational TDWRs throughout the United States. (Not complete.)
Summary
Gust front detection is an important Initial Operational Capability (IOC) of the Integrated Terminal Weather System (ITWS). The Machine Intelligent Gust Front Algorithm (MIGFA) being deployed for ITWS uses multi-dimensional, knowledge-based signal processing techniques to detect and track gust fronts in Terminal Doppler Weather Radar (TDWR) data. Versions of MIGFA...
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