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ASR-9 Weather System Processor (WSP): wind shear algorithms performance assessment
May 7, 1996
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-247
Summary
Lincoln Laboratory has developed a prototype Airport Surveillance Radar Weather Systems Processor (ASR-WSP) that has been used for field measurements and operational demonstrations since 1987. Measurements acquired with this prototype provide an extensive data base for development and validation of the algorithms the WSP uses to generate operational wind shear information for Air Traffic Controllers. This report addresses the performance of the current versions of the WSP's microburst and gust front wind shear detection algorithms on available data from each of the WSP's operational sites. Evaluation of the associated environmental characteristics (e.g., storm structure, radar ground clutter environment) allows for generalization of results of the other major U.S. climatic regimes where the production version of WSP will be deployed.
Summary
Lincoln Laboratory has developed a prototype Airport Surveillance Radar Weather Systems Processor (ASR-WSP) that has been used for field measurements and operational demonstrations since 1987. Measurements acquired with this prototype provide an extensive data base for development and validation of the algorithms the WSP uses to generate operational wind shear...
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Selected abstracts on aviation weather hazard research
January 2, 1996
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-242
Summary
This paper consists of bibliographic information and abstracts for literature on the topics of weather-related aviation hazards. These abstracts were selected from reports written for the ASR-9, ITWS, TDWR programs, sponsored by the Federal Aviation Administration (FAA), and the Wake Vortex program, sponsored by NASA Langley Research Center. All research was performed by MIT Lincoln Laboratory; some research was performed in collaboration with other organizations. These abstracts were compiled to allow participants in the ASR-9 program to conduct research related to their design, development, and production effort. The abstracts and bibliographic information were retrieved from several commercial databases (INSPEC, Ei Compendex*Plus, Aerospace Database, and NTIS) through an open literature search at the Lincoln Laboratory library. Sufficient information is included for readers to obtain documents of interest to them, but documents will not be provided directly by Lincoln Laboratory.
Summary
This paper consists of bibliographic information and abstracts for literature on the topics of weather-related aviation hazards. These abstracts were selected from reports written for the ASR-9, ITWS, TDWR programs, sponsored by the Federal Aviation Administration (FAA), and the Wake Vortex program, sponsored by NASA Langley Research Center. All research...
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Initial evaluation of terminal-area atmospheric vertical structure prediction algorithms using Fall 1994 ITWS/Wake Vortex Programs' meteorological data
November 6, 1995
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-237
Summary
A Dynamic Atmospheric Vertical Structure Nowcast System (DAVS-NS) is being developed that will add value to the Integrated Terminal Weather System (ITWS) by providing current and short-term forecasts of the vertical atmospheric structure focused at specific sites within the terminal domain. Operational applications of these estimates of the atmospheric vertical structure include predicting changes in airport operation rates due to ceiling and visibility (C&V) changes and in predicting wake vortex behavior. The core of this system would be a one-dimensional boundary layer column model. This report summarizes the evaluation of a modified Oregon State University (OSU) column model using data collected during the fall 1994 combined National Aeronautics and Space Administration (NASA) wake vortex project and the ITWS site operations at Memphis International Airport (MEM). Further efforts are necessary to develop and test an operational DAVS-NS prototype. The accuracy typically seen in column model predictions of the vertical temperature structure will limit errors in wake vortex dissipation rates to within a factor of two. Given the current working hypothesis for the San Francisco stratus burn-off phenomenon that rests largely on warming of the marine boundary layer by surface heat flux, the OSU model will also appear to be well suited for addressing this particular problem.
Summary
A Dynamic Atmospheric Vertical Structure Nowcast System (DAVS-NS) is being developed that will add value to the Integrated Terminal Weather System (ITWS) by providing current and short-term forecasts of the vertical atmospheric structure focused at specific sites within the terminal domain. Operational applications of these estimates of the atmospheric vertical...
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Terminal Weather Information for Pilots (TWIP) Test Report for 1994 Memphis and Orlando Demonstrations
April 28, 1995
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-227
Summary
Demonstrations of delivering the Terminal Weather Information for Pilots (TWIP) products to air carrier pilots via the Aircraft Communications Addressing and Reporting System (ACARS) data link were carried out at Memphis and Orlando during the summer of 1994. Six airlines participated in the demonstrations at both airports. The Terminal Weather Text Message and the Terminal Weather Character Graphics Depiction were evaluated using request/reply and forced update approaches. In the first case, the pilot needed to make a request in order to obtain the TWIP products. In the second case, the TWIP message was sent to the aircraft automatically when certain criteria were met (e.g., the aircraft was within 20 minutes of landing and wind shear alerts began at the airport). Five of the airlines used the request/reply approach, and one airline used the forced update approach. Pilot and contoller response to the TWIP products were evaluated using questionnaires. Statistics on message traffic and content were analyzed, and some cases were analyzed in detail to compare the TWIP products with the existing Surface Aviation Observation (SAO) reports. Recorded radio traffic also was analyzed to determine if there was any effect on the number of requests for terminal weather information. Pilots rated the TWIP products favorably, with most indicating that the messages provided improved situational awareness of terminal weather hazards without substantially increased cockpit workload. Controller reaction to the TWIP demonstration was generally neutral, indicating that providing these messages to pilots caused no substantial increase in contoller workload. Further results of the demonstration are discussed in the report, along with recommendations for subsequent TWIP demonstrations.
Summary
Demonstrations of delivering the Terminal Weather Information for Pilots (TWIP) products to air carrier pilots via the Aircraft Communications Addressing and Reporting System (ACARS) data link were carried out at Memphis and Orlando during the summer of 1994. Six airlines participated in the demonstrations at both airports. The Terminal Weather...
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Initial evaluation of the Oregon State University Planetary Boundary Layer Column Model for ITWS applications
April 13, 1995
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-233
Summary
The Federal Aviation Administration (FAA) Integrated Terminal Weather System (ITWS) is supporting the development of products important for air traffic control in the terminal area. Some ITWS is supporting the development of products important for air traffic control in the terminal area. Some ITWS products will allow air traffic managers to anticipate operationally significant short-term (0-30 min) changes in ceiling and visibility (C&V) and aircraft separations necessary to avoid encounters with wake vortices. Development of such products exploits data that will be available from new FAA terminal area sensor systems. These sensor systems include Terminal Doppler Weather Radar (TDWR), Next Generation Weather Radar (NEXRAD), the Meteorological Data Collection and Reporting System (MDCRS), and the Automated Surface Observing System (ASOS). A Dynamic Atmospheric Vertical Structure Nowcast System (DAVS-NS) is being developed that will add value to ITWS by providing current analyses and short-term forecasts of the vertical atmospheric structure focused at specific sites within the terminal domain. This report summarizes the initial evaluation of the Oregon State University one-dimensional boundary layer model for its potential role within a DAVS-NS.
Summary
The Federal Aviation Administration (FAA) Integrated Terminal Weather System (ITWS) is supporting the development of products important for air traffic control in the terminal area. Some ITWS is supporting the development of products important for air traffic control in the terminal area. Some ITWS products will allow air traffic managers...
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Integrated Terminal Weather System (ITWS) demonstration and validation operational test and evaluation
April 13, 1995
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-234
Summary
During summer 1994, MIT Lincoln Laboratory conducted the Operational Test and Evaluation Demonstration and Validation (Dem Val) of the Federal Aviation Administration's Integrated Terminal Weather System (ITWS). The purpose of the demonstration was to obtain user feedback on products and to prove that the ITWS products and concept were sufficiently mature to proceed with procurement. Dem Val was conducted at the Memphis International Airport from 23 May through 22 July and at the Orlando International Airport from 11 July through 19 August. Products were delivered to users at the Memphis Airport Traffic Control Tower (ATCT) and TRACON (Terminal Radar Approach Control), at the Memphis Air Route Traffic Control Center (ARTCC), at the Orlando International ATCT and TRACON, and at the Jacksonville ARTCC. In addition, ITWS displays were available to the National Weather Service forecast offices at Memphis, TN, and Melbourne, FL; to Northwest Airlines in Minneapolis, MN; and to Delta Airlines in Orlando, FL. This report documents the technical performance of the product generation algorithms. Each algorithm is described briefly, including the product operational and display concepts. The techniques by which the technical performance is assessed and the results of the assessment are presented. The performance of the algorithms is measured against the Minimum Operational Performance Requirements (MOPR), which products must meet to be considered operationally useful by the ATC user community.
Summary
During summer 1994, MIT Lincoln Laboratory conducted the Operational Test and Evaluation Demonstration and Validation (Dem Val) of the Federal Aviation Administration's Integrated Terminal Weather System (ITWS). The purpose of the demonstration was to obtain user feedback on products and to prove that the ITWS products and concept were sufficiently...
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The ITWS Runway Wind Nowcast Product
January 15, 1995
Conference Paper
Published in:
Sixth Conf. on Aviation Weather Systems, 15-20 January 1995, pp. 390-395.
Summary
The Runway Wind Nowcast Product will support the ITWS objective by providing short term (up to 30 minutes) forecasts of the tailwind and crosswind components of the horizontal wind over each runway at an ITWS airport. These forecasts will enable FAA users to better anticipate wind shifts impacting runway usage and trajectories of approaching and departing air traffic. They may also support future ITWS products such ceiling and visibility nowcasts. Our initial development efforts, which are reported here, have been directed toward Orlando International Airport (MCO) as the product request originated there. However, in the near future we plan to expand the scope to include other ITWS airports including Memphis. The Runway Wind Nowcast Product is being developed to help Air Traffic Control (ATC) personnel answer the following question: Do we need to change runways? That would become necessary if tailwinds or crosswinds exceed usage thresholds. At most US airports, with dry runways, tailwinds much be less than five knots and crosswinds must be less than 15 knots. Other, lower thresholds apply if the runways are wet. However, these thresholds are subject to local modifications. For example, the MCO tailwind threshold for dry runways is 7 knots. The decision faced by ATC personnel seems, at first, to be clear cut: if the tailwind or crosswind exceeds nominal thresholds, use of that runway must be discontinued. The problem (at least at MCO) is that most threshold crossings are very brief. So, it may be better to temporarily hold traffic than to switch runways. Reliable (i.e., accurate and precise) short term forecasts will help ATC personnel make better hold-or-switch decisions.
Summary
The Runway Wind Nowcast Product will support the ITWS objective by providing short term (up to 30 minutes) forecasts of the tailwind and crosswind components of the horizontal wind over each runway at an ITWS airport. These forecasts will enable FAA users to better anticipate wind shifts impacting runway usage...
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TDWR scan strategy implementation
September 2, 1994
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-222
Summary
The Terminal Doppler Weather Radars (TDWRs) installed at major airports around the country are intended to enhance the safety of air travel by the detection and timely warning of hazardous wind shear conditions in the airport terminal area. To meet these objectives, scan strategies to efficiently cover the protected airspace were developed after extensive testing at several sites with different meteorological environments. Since the topology and geometry differ at each TDWR location, special considerations were necessary to define the specific scan sequences for each site. This report describes the criteria used to establish these scan sequences, including the determination of the lowest practicable elevation angle for each site - the "surface scan," which is used to detect microburst surface outflows, and other special scans such as the "MTS scan," which is used to illuminate the remote Moving Target Simulator (MTS).
Summary
The Terminal Doppler Weather Radars (TDWRs) installed at major airports around the country are intended to enhance the safety of air travel by the detection and timely warning of hazardous wind shear conditions in the airport terminal area. To meet these objectives, scan strategies to efficiently cover the protected airspace...
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Implementation of the 1992 Terminal Area-Local Analysis and Prediction System (T-LAPS)
August 22, 1994
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-219
Summary
The Integrated Terminal Weather System (ITWS) development program was initiated by the Federal Aviation Administration (FAA) to produce a fully automated, integrated terminal weather information system to improve the safety, efficiency and capacity of terminal area aviation operations. The ITWS will acquire data from FAA and National Weather Service (NWS) sensors as well as from aircraft in flight in the terminal area. The ITWS will provide air traffic personnel with products that are immediately usable without further metorological interpretation. These products include current terminal area weather and short-term (0-30 minute) predictions of significant weather phenomena. The Terminal area-Local Analysis and Prediction System (T-LAPS) is being evaluated as a possible provider of the Terminal Winds Product for the ITWS. T-LAPS is a direct descendant of the Local Analysis and Prediction System (LAPS) developed at the National Oceanic and Atmospheric Administraiton's (NOAA's) Forecast Systems Laboratory (FSL). T-LAPS takes meteorological data from a wide variety of data sources as input and provides a gridded, three-dimensional (3-D) analysis of the state of the local atmosphere in the terminal area as output. For the 1992 system, the output was a gridded 3-D analysis of the horizontal winds. This information is intended to be used by the Terminal Air Traffic Control Automation (TATCA) program to estimate the effects of winds on aircraft in the terminal area. The 1993 and 1994 T-LAPS systems will incorporate more sophisticated wind analysis algorithms. The T-LAPS '92 demonstration at the Lincoln Laboratory Terminal Doppler Weather Radar (TDWR) FL-2CC field site in Kissimmee, Florida, during August and September was quite successful. The primary area of coverage was a 120 km by 120 km box centered on the Orlando International Airport. The T-LAPS system was able to utilize radar information from both the TDWR testbed and the operational NEXRAD/WSR-88D radar in Melbourne, Florida. This report documents the implementation of the T-LAPS system that was run during the 1992 summer demonstration and discusses the design and some implementation details of the system.
Summary
The Integrated Terminal Weather System (ITWS) development program was initiated by the Federal Aviation Administration (FAA) to produce a fully automated, integrated terminal weather information system to improve the safety, efficiency and capacity of terminal area aviation operations. The ITWS will acquire data from FAA and National Weather Service (NWS)...
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Terminal Doppler Weather Radar (TDWR) Low Level Wind Shear Alert System 3 (LLWAS 3) integration studies at Orlando International Airport Airport in 1991 and 1992
April 20, 1994
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-216
Summary
In 1993 the Federal Aviation Administration (FAA) began deploying two new wind shear detectionsystems: the Terminal Doppler Weather Radar (TDWR) and the third-generation Low Level Windshear Alert System (LLWAS 3). Currently, nine airports are scheduled to receive both a TDWR and an LLWAS 3. This number may eventually increase to as high as 45. When co-located, the systems will be integrated to provide a single set of wind shear alerts and improve system performance. The TDWR production schedule required one of three integration algorithms to be chosen for specification by fall 1991. The three algorithms are the prototype integration algorithm developed at the National Center for Atmospheric Research (NCAR) and two algorithms developed at MIT Lincoln Laboratory (MIT/LL). To assess the performance of the three algorithms, MIT/LL performed a study of the integration, TDWR, and LLWAS 3 algorithms at Orlando International Airport in the summer of 1992. We discuss results of the 1991 comparative study and a follow-up study of the TDWR, LLWAS 3, and Message Level integration algorithms at Orlando in 1992. All of the algorithms met the requirement of detecting 90 percent of microburst level wind shear with loss events. LLWAS 3, Build 5 TDWR, and the MIT/LL integration algorithms run with Build 5 TDWR, all met the requirement that less than 10 percent of wind shear alerts be false. The NCAR prototype did not utilize Build 5 TDWR. Build 4 TDWR and all integration algorithms run with Build 4 TDWR did not meet the false-alert requirement. Detailed descriptions of the algorithms are given. The methodology for estimating various algoirthm performance statistics based on a comparison with a dual-Doppler algorithm is detailed.
Summary
In 1993 the Federal Aviation Administration (FAA) began deploying two new wind shear detectionsystems: the Terminal Doppler Weather Radar (TDWR) and the third-generation Low Level Windshear Alert System (LLWAS 3). Currently, nine airports are scheduled to receive both a TDWR and an LLWAS 3. This number may eventually increase to...
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