Publications
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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R&D area:
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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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The Corridor Integrated Weather System (CIWS)
May 13, 2002
Conference Paper
Published in:
10th Conf. on Aviation, Range, and Aerospace Meteorology, 13-16 May 2002, pp. 210-215.
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R&D area:
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Summary
The FAA Operational Evolution Plan (OEP) identified en route severe weather as one of the four problems that must be addressed if the US. air transportation system is to alleviate the growing gap between the demand for air transportation and the ability of the system to meet that demand. Convective weather in highly congested airspace is of particular concern because many of the delays arise from these corridors. For example, rerouting aircraft around areas of actual or predicted weather can be very difficult when one must be concerned about controller overload in the weather free sectors. When major terminals also underlie the en route airspace, convective weather has even greater adverse impacts. The principal thrust to date in addressing this problem has been "strategic" collaborative routing as exemplified by the "Spring 2000" and "Spring 2001" initiatives. However, success of the strategic approach embodied in these initiatives depends on the ability to accurately forecast convective weather impacts two or more hours in advance. Limitations in the forecast accuracy necessitate development of a companion "tactical" convective weather capability. In this paper, we describe a major new FAA initiative, the Corridor Integrated Weather System (CIWS). The objective of this project, which is currently in the concept exploration phase, is to improve tactical convective weather decision support for congested en route airspace. A real time operational demonstration, which was begun in July 2001 in the Great Lakes corridor, will be extended to the Northeast corridor in 2002. In the sections that follow, we describe the operational needs that motivated the ClWS initiative, the technology under investigation, the concept exploration test bed and summer 2001 operational experience, and the near term plans for the CIWS concept exploration.
Summary
The FAA Operational Evolution Plan (OEP) identified en route severe weather as one of the four problems that must be addressed if the US. air transportation system is to alleviate the growing gap between the demand for air transportation and the ability of the system to meet that demand. Convective...
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Analysis of delay causality at Newark International Airport
December 3, 2001
Conference Paper
Published in:
4th USA/Europe Air Traffic Management R&D Seminar, 3-7 December 2001.
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R&D area:
Summary
Determining causes of aviation delay is essential for formulating and evaluating approaches to reduce air traffic delays. An analysis was conducted of large weather-related delays at Newark International Airport (EWR), which, located in the heart of the congested northeast corridor of the United States, is an airport with a significant number of delays. Convective weather and reduced ceiling and visibility were found to be the leading contributors to large delays at EWR between September 1998 and August 2001. It was found that 41% of the cumulative arrival delay (delay relative to schedule) on days in this period averaging more than 15 minutes of delay per arrival occurred on days characterized by convective weather either within or at considerable distances from the New York terminal area. Of the remaining delays, 28% occurred on days characterized by low ceiling/visibility conditions, while 14% occurred on fair weather days with high surface winds, and 2% were caused by distant non-convective storms. Known causes other than weather accounted for 9% of the delays, and causes were unknown for 6%. When delay types (airborne, gate, taxi -out etc.) were categorized by the type of weather causing the delay, it was found that: (1) departure delays (gate + taxi-out) were much larger than arrival delays for thunderstorms in the NY terminal area and (2) taxi-out delays were the dominant type when delays were caused by distant convective weather. The fraction of total delay time explained by pre-planned Ground Delay Programs (GDP) rose sharply during 2000, accounting for over 40% of total the arrival delay that year, and then decreased slightly in 2001. On days with thunderstorms in the NY TRACON, arrival and departure delays were significantly higher during the year (2000) that GDPs were used most frequently.
Summary
Determining causes of aviation delay is essential for formulating and evaluating approaches to reduce air traffic delays. An analysis was conducted of large weather-related delays at Newark International Airport (EWR), which, located in the heart of the congested northeast corridor of the United States, is an airport with a significant...
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Tactical convective weather decision support to complement "strategic" traffic flow management for convective weather
November 4, 2001
Conference Paper
Published in:
46th Annual Air Traffic Control Association Conf. Proc., 4-8 November 2001, pp. 98-102.
Summary
Delay increases during the months of the year characterized by thunderstorms have been the principal cause of the dramatic delay growth in the US aviation system over the past 3 years, as shown in Figure 1. In 2000, the key new initiative for reducing these convective weather delays was "strategic" traffic flow management (TFM) through the Collaborative Convective Forecast Product (CCFP), the Strategic Planning Team, and Collaborative Routing (CR). This "strategic" approach has been quite successful in improving operations. However, in congested airspace, the inability to accurately forecast convective weather impacts requires a complementary tactical weather decision support capability. This paper describes terminal and enroute weather prediction systems plus traffic flow management and automation decision support tools to complement the strategic approach.
Summary
Delay increases during the months of the year characterized by thunderstorms have been the principal cause of the dramatic delay growth in the US aviation system over the past 3 years, as shown in Figure 1. In 2000, the key new initiative for reducing these convective weather delays was "strategic"...
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Delay causality and reduction at the New York City airports using terminal weather information systems
February 16, 2001
Project Report
Published in:
Project Report ATC-291, MIT Lincoln Laboratory
Summary
Adverse weather accounts for the bulk of the aviation delays at the major New York City airports. In this report, we quantify: 1. Aviation delay reduction with an Integrated Terminal Weather System (ITWS) that incorporates the 30-60 minute predictions of convective storms generated by the Terminal Convective Weather Forecast (TCWF) algorithm, 2. Principal causes of aviation delays with the ITWS in operation, and 3. The extent to which the current delays are "avoidable". We find that improved decision making by the New York FAA users of ITWS provides an annual delay reduction of over 49,000 hours per year with a monetary value of over $150,000,000 per year. Convective weather was found to be the leading contributor to delays at Newark International Airport (EWR) between September 1998 and August 2000. It was found that 40% of the arrival delay in this study occurred in association with delay days characterized by convective weather both within and at considerable distances from the New York terminal area. Of the remaining delay, 27% occurred on days characterized by low ceiling/visibility conditions, while 16% occurred on fair weather days with high surface winds. We also concluded that many of the delays which occur with the current ITWS, over $1,500,000 in one case, could be avoided if the ITWS were extended to provide: 1. Predictions of thunderstorm decay, and 2. Predictions of the onset and ending of capacity limiting events such as low ceilings or high surface winds. These delay causality results are very important for studies of the effectiveness of changes made to the U.S. aviation system to reduce delays at airports such as Newark as well as for prioritizing FAA research and development expenditures.
Summary
Adverse weather accounts for the bulk of the aviation delays at the major New York City airports. In this report, we quantify: 1. Aviation delay reduction with an Integrated Terminal Weather System (ITWS) that incorporates the 30-60 minute predictions of convective storms generated by the Terminal Convective Weather Forecast (TCWF)...
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Airline operations center usage of FAA terminal weather information products
September 11, 2000
Conference Paper
Published in:
Ninth Conf. on Aviation, Range, and Aerospace Meteorology, 11-15 September 2000, pp. 76-81.
Summary
Adverse terminal weather is a key factor in the safety and efficiency of airline operations. Weather has been directly related to many of the air carrier accidents with fatalities in the 1990's, and the cost to airlines per year for weather delays is estimated to exceed one billion dollars, with at least half of this arising from convective weather. This paper discusses the airline operations center (AOC) use of information from the Federal Aviation Administration (FAA) terminal weather systems to improve safety and operational efficiency (e.g., reduce delays and diversions, improve predictability, and airline schedule integrity) during severe or rapidly changing conditions. Historically (e.g., prior to 1992), the FAA terminal weather information capability was fairly rudimentary, and airlines had no access to the information. However, with deployment of the ITWS, the ASR-9 Weather Systems Processor (WSP) production systems, and CDMnet (and perhaps Internet) product servers for ITWS and WSP airlines will have access to the products. Thus, it is important now to consider how these products could be used operationally and what refinements should be made to the ITWS/WSP products to better meet the needs of airline users.
Summary
Adverse terminal weather is a key factor in the safety and efficiency of airline operations. Weather has been directly related to many of the air carrier accidents with fatalities in the 1990's, and the cost to airlines per year for weather delays is estimated to exceed one billion dollars, with...
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Extending the Integrated Terminal Weather System (ITWS) to address urgent terminal area weather needs
September 11, 2000
Conference Paper
Published in:
Ninth Conf. on Aviation, Range, and Aerospace Meteorology, 11-15 September 2000, pp. 153-158.
Summary
Major terminals and the surrounding en route airspace are critical elements of the US National Air System (NAS). A large fraction of the US population lives near these terminals, and the bulk of the hub connecting operations are at these airports as well. Adverse weather in these terminal areas and surrounding en route airspace is a major safety concern for the NAS as well as causing a large fraction of all US aviation delays. The principal weather decision support tool for these terminals is the Integrated Terminal Weather System (ITWS) which commenced full-scale development by the FAA in 1995, with first articles to be deployed shortly. In this paper, we discuss how the initial ITWS operational capability needs to be extended to address performance problems identified in operational use and to meet the many new user needs that have developed in the past five years. The paper proceeds as follows. In Section 2, we provide some necessary background on the ITWS operational capability, followed by a discussion of new capabilities to meet urgent user needs. Section 3 discusses refinements to the initial capability to address problems/issues that have been identified based on five years of operational use of ITWS products from ITWS demonstration systems at eight major airports. Next, we consider extending planned ITWS coverage to other major terminals. The final section summarizes the paper's results and suggests additional studies.
Summary
Major terminals and the surrounding en route airspace are critical elements of the US National Air System (NAS). A large fraction of the US population lives near these terminals, and the bulk of the hub connecting operations are at these airports as well. Adverse weather in these terminal areas and...
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Measurement of hazardous winter storm phenomena at the Portland OR International Airport
September 11, 2000
Conference Paper
Published in:
Ninth Conf. on Aviation, Range, and Aerospace Meteorology, ARAM, 11-15 September 2000, pp. 525-530.
Summary
Wind shear and lightning are classically associated with summertime convective weather events at airports east of Reno, NV. However, a recent study concluded that severe wind shear and lightning strike events occasionally occur during winter storms at west coast airports. One of the most surprising findings was that the Portland Oregon International Airport (PDX) has operationally significant vertical wind shear and a surprisingly high number of lightning strikes to aircraft within the terminal area during winter storms. The FAA has for a number of years planned to install an ASR-9 Weather System Processor (WSP) at PDX to provide protection against wind shear from microbursts and gust fronts. However, in view of the findings of the west coast weather study (conducted after the FAA's wind shear deployment study was completed, a research program was undertaken to: Better understand the phenomenology associated with the Portland winter storms; Determine whether the baseline ASR-9 Weather System Processor planned for PDX would adequately address operationally significant wind shear and other safety-related weather phenomena; and Identify alternative sensing/data fusion approaches to providing PDX terminal weather decision support if the WSP alone could not adequately provide safety warnings.
Summary
Wind shear and lightning are classically associated with summertime convective weather events at airports east of Reno, NV. However, a recent study concluded that severe wind shear and lightning strike events occasionally occur during winter storms at west coast airports. One of the most surprising findings was that the Portland...
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Operational experience with weather products generated through joint use of FAA and NWS weather radar sensors
September 11, 2000
Conference Paper
Published in:
Ninth Conf. on Aviation, Range, and Aerospace Meteorology and 20th Conf. on Severe Local Storms, 11-15 September 2000, pp. J19-J23.
Summary
In this paper, we describe current joint use of Federal Aviation Administration (FAA) and National Weather Service (NWS) radar sensors to provide operational weather decision support for the FAA, airline operations centers, and NWS forecast offices. The capabilities that have been demonstrated include fully automatic data editing and short term "nowcast" product generation algorithms as well as display of data from the different radars in different windows; direct product distribution to operational decision makers without any intervening meteorologist input; and collaborative decision making between the various parties. The significant use of fully automated product generation algorithms has facilitated flexible, coordinated decision making in real time at many locations simultaneously, without the high personnel costs that would be required to achieve the same weather product generation capability manually through interpretation by experienced radar meteorologist/forecasters. These joint-use capabilities have been demonstrated operationally at the Integrated Terminal Weather System (ITWS) demonstration sites in Memphis, TN, Orlando, FL, Dallas, TX, and Garden City, NY. These sites have provided operational service for the four major terminal areas since 1994.1 Specific capabilities used operationally by FAA- and airline users, which are discussed in the next section, include: 1. Addressing radar data quality issues such as rain attenuation and AP-induced ground clutter contamination, 2. High update rates for detection of rapidly changing weather while also obtaining 3D information on storms, 3. Estimating 3D winds, and 4. Reducing the fraction of phenomena that are not accurately characterized because the radars can directly measure radial velocity only. Section 3 discusses the operational usage of integrated products by NWS forecast offices at the ITVVS demonstration sites. The paper concludes with a summary of the operational uses to date and makes some suggestions for NWS and USAF use of FAA radar sensors in conjunction with NEXt generation weather RADars (NEXRAD).
Summary
In this paper, we describe current joint use of Federal Aviation Administration (FAA) and National Weather Service (NWS) radar sensors to provide operational weather decision support for the FAA, airline operations centers, and NWS forecast offices. The capabilities that have been demonstrated include fully automatic data editing and short term...
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Weather sensing and data fusion to improve safety and reduce delays at major west coast airports
September 11, 2000
Conference Paper
Published in:
Ninth Conf. on Aviation, Range, and Aerospace Meteorology, 11-15 September 2000, pp. 102-107.
Summary
In this paper we present results from a recently completed study of weather sensing and data fusion to improve safety and reduce delays at major west coast airports. With the exception of a summer stratus burn-off prediction project at San Francisco, these airports have received much less attention in terms of advanced FAA terminal weather decision support systems than major airports east of Los Angeles. This is because the principal concern for terminal weather decision support to date has been microburst-induced wind shear, which is very infrequent at the west coast airports. However, three factors warrant a reexamination of weather decision support provided to these major west coast airports: 1. The increased emphasis on significantly improving aviation safety while reducing delays at major airports in the face of expected increases in operations rates within the National Airspace System (NAS), 2. New air traffic management technology such as terminal automation, collaborative decision making (CDM), and weather adaptive wake vortex spacing systems, and 3. Advances in terminal weather decision support technology represented by the Integrated Terminal Weather System (ITWS) [including various P31 enhancements to ITWS (Evans and Wolfson, 2000)] The airports considered in this study were the Los Angeles (LAX), San Francisco (SFO), Portland (PDX) and Seattle (SEA) International Airports. It should be noted that because these airports did not receive a Terminal Doppler Weather Radar, there currently is no plan to provide them with an ITWS. LAX, SF0 and PDX are scheduled to receive an ASR-9 Weather System Processor (WSP). The paper proceeds as follows. Section 2 discusses the study's methodology and provides background information on delays and weather phenomena for these airports in the context of other major US airports as well as applicable air traffic management (ATM) and terminal weather system technology. Section 3 summarizes the principal findings for the four airports. We conclude with a summary of the potential benefits of improved weather sensing and data fusion that might be provided at these west coast airports by an augmented ITWS as well as recommendations for further studies.
Summary
In this paper we present results from a recently completed study of weather sensing and data fusion to improve safety and reduce delays at major west coast airports. With the exception of a summer stratus burn-off prediction project at San Francisco, these airports have received much less attention in terms...
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