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An improved gust front detection capability for the ASR-9 WSP
May 13, 2002
Conference Paper
Published in:
10th Conf. on Aviation, Range, and Aerospace Meteorology, 13-16 May 2002, pp. 379-382.
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Summary
The Weather Systems Processor (WSP) is being deployed by FAA at 35 medium and high-density ASR-9 equipped airports across the United States. The Machine Intelligent Gust Front Algorithm (MIGFA) developed at Lincoln Laboratory provides important gust front detection and tracking capability for this system as well as other FAA systems including Terminal Doppler Weather Radar (TDWR) and Integrated Terminal Weather System (ITWS). The algorithm utilizes multidimensional image processing, data fusion, and fuzzy logic techniques to recognize gust fronts observed in Doppler radar data. Some deficiencies in algorithm performance have been identified through ongoing analysis of data from two initial limited production WSP sites in Austin, TX (AUS) and Albuquerque, NM (ABQ). At AUS, the most common cause of false alarms is bands of low-reflectivity rain echoes having shapes and intensities similar to gust front thin line echoes. Missed or late detections have occasionally occurred when gust fronts are near or embedded in the leading edge of approaching line storms, where direct radar evidence of the gust front (e.g.. thin line echo, velocity convergence) may be fragmented or absent altogether. In ABQ, "canyon wind" events emanating, from mountains located just east of the airport occur with very little lead time, and often with little or no radar signatures, making timely detection on the basis of the radar data alone difficult. MIGFA is equipped with numerous parameters and thresholds that can be adjusted dynamically based on recognition of the local or regional weather context in which it is operating. Through additional contextual weather information processing, this dynamic sensitization capability has been further exploited to address the deficiencies noted above, resulting in an appreciable improvement in performance on data collected at the two WSP sites.
Summary
The Weather Systems Processor (WSP) is being deployed by FAA at 35 medium and high-density ASR-9 equipped airports across the United States. The Machine Intelligent Gust Front Algorithm (MIGFA) developed at Lincoln Laboratory provides important gust front detection and tracking capability for this system as well as other FAA systems...
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Aircraft encounters with thunderstorms in enroute vs. terminal airspace above Memphis, Tennesssee
May 13, 2002
Conference Paper
Published in:
Proc. 10th Conf. on Aviation, Range and Aerospace Meteorology, 13-16 May 2002, pp. 162-165.
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To date, very little attention has been given to quantifying the effects of thunderstorms on air traffic in enroute airspace. What types of storms cause pilots to deviate from their nominal flight routes? What types of storms do pilots fly through? Around? Over? When thunderstorms are forecast to affect a particular region, how many planes will need to be rerouted? Which ones? Which aspects of the storm need to be accurately forecast in order to answer those questions? How does the forecast accuracy affect the quality of airspace capacity predictions? Quantitative answers to these questions would contribute to the design of useful decision support tools. Federal Aviation Administration decision support tools are being equipped with the ability for air traffic managers to define dynamic "flow constrained areas" (FCAs). Each FCA will be a polygon in latitude/longitude space with ceiling and floor altitudes and a motion vector. One primary use for FCAs will be to define regions that do, or probably will, contain convective thunderstorm activity. These tools will help air traffic managers decide which planes to re-route around the weather and which planes have a reasonable chance of flying through, between, or over the storms. Although it will be helpful to have the ability to manually define FCAs in the traffic managers' tools, the efficiency of the solutions that will be worked out with those tools would be greatly enhanced by answers to the questions posed above. In our prior work we have attempted to quantify the behavior of pilots who encounter thunderstorms in terminal airspace during the final 60 nautical miles of flight. In this study we compare the storm avoidance behavior of pilots in enroute airspace with that of pilots who encountered the very same storms at lower altitudes, in terminal airspace. The study is preliminary, but it complements the terminal work, affords some insight into pilot behavior, and raises questions that should be addressed in a larger study.
Summary
To date, very little attention has been given to quantifying the effects of thunderstorms on air traffic in enroute airspace. What types of storms cause pilots to deviate from their nominal flight routes? What types of storms do pilots fly through? Around? Over? When thunderstorms are forecast to affect a...
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An evaluation of the Medium-Intensity Airport Weather System (MIAWS) products at the Memphis, TN and Jackson, MS International Airports
May 13, 2002
Conference Paper
Published in:
10th Conf. on Aviation, Range, and Aerospace Meteorology (13th Conf. on Applied Climatology), 13-16 May 2002, pp. J118-J122.
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Summary
The FAA is procuring aviation weather systems, which are designed to enhance safety/capacity and reduce delays at U.S. airports. The two most widely publicized systems currently being installed are the Integrated Terminal Weather System (ITWS) at airports equipped with a Terminal Doppler Weather Radar (TDWR) and the Weather System Processor (WSP) at those terminal areas covered by an Airport Surveillance Radar, Model 9 (ASR-9). At airports not slated to receive either an ITWS or WSP, an emerging system coined the Medium Intensity Airport Weather System (MIAWS) will be installed. Currently, either an ASR-7 or 8 provides terminal aircraft surveillance at these airports. Unfortunately, these platforms do not output calibrated precipitation intensity or storm motion information. Quantitative six-level weather reflectivity data will be available once the digitally enhanced ASR-11 radar system is operational at MIAWS supported sites. The Low Level Wind Shear Alert System - Relocation/Sustainment (LLWAS-RS) anemometer network will provide MIAWS with surface-based winds and wind shear alerts. The rationale for MIAWS evolved from the ITWS and WSP prototype testing. The premise is that the calibrated reflectivity and velocity data from state-of-the-art radar platforms can be utilized to produce a suite of current and forecasted storm positions to aid air traffic control decision making. The forecasted location is a critical issue if the storms are moving rapidly. This can lead to a scenario where the weather conditions deteriorate significantly within a matter of minutes. Once implemented, MIAWS will be an essential component of the National Airspace System by providing this evolving technology to airports whose traffic counts are not sufficient to warrant either an ITWS or WSP, but where commercial carriers could reap the benefits of a high-quality weather radar system. The FAA has contracted the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL) to undertake a proof-of-concept evaluation of MIAWS. To this end, MIT/LL installed two prototype systems at the Jackson, MS (JAN) and Memphis, TN (MEM) International Airports. The system at MEM is used solely for product evaluation and refinement, while the FAA is operationally evaluating the JAN MIAWS. The focus of this report is a preliminary assessment of the capabilities and limitations of MIAWS in its current implementation, i.e. precipitation based solely on NEXRAD data. Potential enhancements to the NEXRAD product data and MIAWS algorithms will also be discussed.
Summary
The FAA is procuring aviation weather systems, which are designed to enhance safety/capacity and reduce delays at U.S. airports. The two most widely publicized systems currently being installed are the Integrated Terminal Weather System (ITWS) at airports equipped with a Terminal Doppler Weather Radar (TDWR) and the Weather System Processor...
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The 2001 demonstration of automated cloud forecast guidance products for San Francisco International Airport
May 13, 2002
Conference Paper
Published in:
10th Conf. on Aviation, Range, and Aerospace Meteorology (13th Conf. on Applied Climatology), 13-16 May 2002, pp. J99-J102.
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A system for providing cloud prediction guidance to aviation weather forecasters was demonstrated during the summer of 2001. The system was sponsored by the FAA, and developed by MIT Lincoln Laboratory in collaboration with SJSU, the University of Quebec at Montreal, Penn State University, and the Central Weather Service Unit (CWSU) at Oakland Center. Products were provided to forecasters at the CWSU, the NWS in Monterey, and the Weather Center at United Airlines. Real-time data are processed to support a display of weather graphics, and to provide input to a suite of four independent cloud forecast models developed specifically for the marine stratus application. The forecast models were run hourly each morning to provide updated forecasts during the evolution of cloud dissipation int he Bay area. As part of each update cycle, the four model forecasts were combined to provide a Consensus Forecast product. Weather observations and forecasts were provided to users on a web browser display.
Summary
A system for providing cloud prediction guidance to aviation weather forecasters was demonstrated during the summer of 2001. The system was sponsored by the FAA, and developed by MIT Lincoln Laboratory in collaboration with SJSU, the University of Quebec at Montreal, Penn State University, and the Central Weather Service Unit...
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Development of automated aviation weather products for ocean/remote regions: scientific and practical challenges, research strategies, and first steps
May 13, 2002
Conference Paper
Published in:
10th Conf. on Aviation, Range, and Aerospace Meteorology, 13-16 May 2002, pp. 57-60.
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From the common and recognizable occurrence of convection, to the sporadic and far less visible reach of volcanic ash, meteorological phenomena impose diverse challenges to the efficiency, economic viability, and safety of flight operations across the global oceans. Those challenges are compounded by special difficulties associated with nowcasting and forecasting for remote areas, such as expansive voids in surface observations and soundings, large forecast domains, communications difficulties, and long-duration flights often needing significant forecast updates. Conspicuously lacking over oceans are the observational capabilities that provide key information about the internal structure of convection - notably radar and lightning detection systems. The long-term oceanic weather development program (OW) outlined here seeks to use improved understanding of the phenomenology of oceanic weather hazards along with new observations, model information and processing tools to fashion automated forecast/briefing products supporting remote oceanic routes. A parallel OW objective (outlined by Lindholm and Bums, 2002, this conference volume) supports in-flight product transfer to the cockpit. Established in March, 2001, the OW program is still in its infancy. Thus, we concentrate here upon strategy and the scientific basis for our plans. Although our work has begun with a focus on low and middle latitudes (Pacific, Atlantic and Gulf of Mexico regions), increasing use of polar routes is likely to raise the priority for products tailored to high latitude regions over the next several years.
Summary
From the common and recognizable occurrence of convection, to the sporadic and far less visible reach of volcanic ash, meteorological phenomena impose diverse challenges to the efficiency, economic viability, and safety of flight operations across the global oceans. Those challenges are compounded by special difficulties associated with nowcasting and forecasting...
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Enhancement to Terminal Doppler Weather Radar to improve aviation weather services
May 13, 2002
Conference Paper
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10th Conf. on Aviation, Range, and Aerospace Meteorology, 13-16 May 2002, pp. 28-31.
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This paper has described work underway to enhance the TDWRs capability to provide wind shear detection services in challenging conditions, and to provide a flexible platform with COTS hardware that would support future improvements. A Radar Data Acquisition (RDA) system retrofit will upgrade the transmitter, receiver and digital signal processing subsystems of the radar to improve the quality of the reflectivity and Doppler imagery generated by the system and to extend its instrumented range. Algorithms have been described for achieving improved rejection of ground clutter and range-folded weather echoes, and reduction of Doppler velocity aliasing. An open COTS-based processing architecture was presented for the TDWR RDA retrofit, and a test program was outlined that is commencing in Oklahoma in the spring of 2002.
Summary
This paper has described work underway to enhance the TDWRs capability to provide wind shear detection services in challenging conditions, and to provide a flexible platform with COTS hardware that would support future improvements. A Radar Data Acquisition (RDA) system retrofit will upgrade the transmitter, receiver and digital signal processing...
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New products for the NEXRAD ORPG to support FAA critical systems
February 9, 2002
Conference Paper
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19th Int. Conf. on Interactive Processing Systems for Meteorology, Oceanography and Hydrology, 9-13 February 2002.
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A number of Federal Aviation Administration (FAA) critical systems rely on products from the NEXRAD (WSR-88D) suite of algorithms. These systems include MIAWS (Medium Intensity Airport Weather System), ITWS (Integrated Terminal Weather System), CIWS (Corridor Integrated Weather System), and WARP (Weather and Radar Processing). With the advent of the NEXRAD Open Radar Product Generator (ORPG), a six-month build cycle has been established for the incorporation of new or improved algorithms. This build cycle provides the mechanism for the integration of new products into the algorithm suite tailored to the needs of these FAA systems now and into the future. Figure 1 is useful for visualizing the MIT/LL ORPGnet. Four of the ORPGnet systems are located at MIT/LL headquartered in Lexington, MA. These four systems form the core of the development center where algorithms are developed for and implemented into the ORPG environment. Part of the development process includes examination of algorithm products created from past weather. A number of utilities are available for playback of various versions of NEXRAD Archive II base data: from tape or disk files in standard or LDM formats. Additionally, MIT/LL operates the CIWS demonstation project for the FAA. The ORPG clones at the development center have access to base data from 26 NEXRAD radars from the Midwest to the East Coast of the United States ingested for CIWS. The FAA has tasked the Massachusetts Institute of Technology's Lincoln Laboratory (MIT/LL) with developing algorithms for the ORPG to address their systems' needs. Many of these algorithms will also prove useful to other users of NEXRAD products such as the National Weather Service and the Department of Defense. MIT/LL has created a network of ten ORPGs, or an ORPGnet, to use for the purpose of developing, testing, and implementing new algorithms targeted to specific builds. The benefits of the ORPGnet will be discussed in more detail later in this paper. MIT/LL has provided improvements to existing algorithms or developed new algorithms for the first three build cycles of the ORPG (Istok et al., 2002; Smalley and Bennett, 2002). Development of more algorithms is currently in progress for upcoming build cycles. In addition to describing ORPGnet, this paper will focus on its use in the development of a new Data Quality Assurance (DQA) algorithm, an improved High Resolution VIL (HRVIL) algorithm, and progress on the development of the enhanced Echo Tops (EET) algorithm; as well as the symbiotic relationship of these algorithms to the FAA critical systems.
Summary
A number of Federal Aviation Administration (FAA) critical systems rely on products from the NEXRAD (WSR-88D) suite of algorithms. These systems include MIAWS (Medium Intensity Airport Weather System), ITWS (Integrated Terminal Weather System), CIWS (Corridor Integrated Weather System), and WARP (Weather and Radar Processing). With the advent of the NEXRAD...
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Contributions to the AIAA Guidance, Navigation & Control Conference
January 23, 2002
Project Report
Published in:
MIT Lincoln Laboratory Report NASA-A-5
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This report contains six papers presented by the Lincoln Laboratory Air Traffic Control Systems Group at the American Institute of Aeronautics & Astronautics (AIAA) Guidance, Navigation and Control (GNC) conference on 6-9 August 2001 in Montreal, Canada. The work reported was sponsored by the NASA Advanced Air Transportation Technologies (AATT) program and the FAA Free Flight Phase 1 (FFPl) program. The papers are based on studies completed at Lincoln Laboratory in collaboration with staff at NASA Ames Research Center. These papers were presented in the Air Traffic Automation Session of the conference and fall into three major areas: Traffic Analysis & Benefits Studies, Weather/Automation Integration, and Surface Surveillance. In the first area, a paper by Andrews & Robinson presents an analysis of the efficiency of runway operations at Dallas/l%. Worth using a tool called PARO, and a paper by Welch, Andrews, & Robinson presents delay benefit results for the Final Approach Spacing Tool (FAST). In the second area, a paper by Campbell, et al. describes a new weather distribution system for the Center/TRACON Automation System (CTAS) that allows ingestion of multiple weather sources, and a paper by van de Venne, Lloyd, & Hogaboom describes the use of the NOAA Eta model as a backup wind data source for CTAS. Also in this area, a paper by Murphy & Campbell presents initial steps towards integrating weather-impacted routes into FAST. In the third area, a paper by Welch, Bussolari, and Atkins presents an initial operational concept for using surface surveillance to reduce taxi delays.
Summary
This report contains six papers presented by the Lincoln Laboratory Air Traffic Control Systems Group at the American Institute of Aeronautics & Astronautics (AIAA) Guidance, Navigation and Control (GNC) conference on 6-9 August 2001 in Montreal, Canada. The work reported was sponsored by the NASA Advanced Air Transportation Technologies (AATT)...
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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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The design and implementation of the new center/TRACON automation system (CTAS) weather distribution system
August 6, 2001
Conference Paper
Published in:
AIAA Guidance, Navigation and Control Conf.: a collection of Technical Papers, Vol. 3, 6-9 August 2001, pp. 1818-1836.
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The National Aeronautics and Space Administration (NASA), working with the Federal Aviation Administration (FAA), is developing a suite of decision support tools, called the Center/TRACON Automation System (CTAS). CTAS tools such as the Traffic Management Advisor (TMA) and Final Approach Spacing Tool (FAST) are designed to increase the efficiency of the air traffic flow into and through Terminal airspace. A core capability of CTAS is the Trajectory Synthesis (TS) software for accurately predicting an aircraft's trajectory. In order to compute these trajectories, TS needs an efficient access mechanism for obtaining the most up-to-date and accurate winds. The current CTAS weather access mechanism suffers from several major drawbacks. First, the mechanism can only handle a winds at a single resolution (presently 40-80 km). This prevents CTAS from taking advantage of high resolution wind from sources such as the Integrated Terminal Weather System (ITWS). Second, the present weather access mechanism is memory intensive and does not extend well to higher grid resolutions. This potentially limits CTAS in taking advantage of improvements in wind resolution from sources such as the Rapid Update Cycle (RUC). Third, the present method is processing intensive and limits the ability of CTAS to handle higher traffic loads. This potentially could impact the ability of new tools such as Direct-To and Multi-Center TMA (McTMA) to deal with increased traffic loads associated with adjacent Centers. In response to these challenges, M.I.T. Lincoln Laboratory has developed a new CTAS weather distribution (WxDist) system. There are two key elements to the new approach. First, the single wind grid is replaced with a set of nested grids for the TRACON, Center and Adjacent Center airspaces. Each and the grids are updated independently of each other. The second key element is replacement of the present interpolation scheme with a nearest-neighbor value approach. Previous studies have shown that this nearest-neighbor method does not degrade trajectory accuracy for the grid sizes under consideration. The new software design replaces the current implementation, known as the Weather Data Processing Daemon (WDPD), with a new approach. The Weather Server (WxServer) sends the weather grids to a Weather Client (WxClient) residing on each CTAS workstation running TS or PGUI (Planview Graphical User Interface) processes. The present point-to-point weather file distribution is replaced in the new scheme with a reliable multi-cast mechanism. This new distribution mechanism combined with data compression techniques greatly reduces network traffic compared to the present method. Other new processes combine RUC and ITWS data in a fail-soft manner to generate the multiple grids. The nearest-neighbor access method also substantially speeds up weather access. In combination with other improvements, the winds access speed is more than doubled over the original implementation.
Summary
The National Aeronautics and Space Administration (NASA), working with the Federal Aviation Administration (FAA), is developing a suite of decision support tools, called the Center/TRACON Automation System (CTAS). CTAS tools such as the Traffic Management Advisor (TMA) and Final Approach Spacing Tool (FAST) are designed to increase the efficiency of...
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