Publications
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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R&D area:
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 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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Weather impacted routes for the Final Approach Spacing Tool (FAST)
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.1843-1850.
Summary
This paper addresses the issue of developing weather-impacted routes for the Final Approach Spacing Tool (FAST). FAST relies on adaptation data that includes nominal terminal area routes and degrees of freedom to generate optimum landing sequences and runway assignments. However, during adverse weather some adapted routes may become unavailable due to the presence of hazardous weather. If FAST continues to generate trajectories using these routes, its schedule will not be accurate during the adverse weather. The objective of the study was to determine methods for incorporating severe weather products and weather-impacted route data into FAST.
Summary
This paper addresses the issue of developing weather-impacted routes for the Final Approach Spacing Tool (FAST). FAST relies on adaptation data that includes nominal terminal area routes and degrees of freedom to generate optimum landing sequences and runway assignments. However, during adverse weather some adapted routes may become unavailable due...
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Using surface surveillance to help reduce taxi delays
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. 1809-1817.
Summary
Taxi delay is the largest of all aviation movement delays. However, taxi-out delays have not received attention equal to that focused on airborne delays because taxi-out delays often result from downstream problems. Also, until recently, there was no practical means of tracking surface movements. New surface surveillance technology will revolutionize surface management by providing data for planning, timing, and monitoring surface operations. This paper proposes a simple aid to help manage departure taxi queues and help exploit existing departure capacity, while avoiding the delays that result from saturated queues and unbalanced runways. The proposed decision aide will use archived surveillance data to quantify queuing behavior and model departure capacity, and it will use real-time surveillance to track capacity changes and monitor the state of the taxi queues.
Summary
Taxi delay is the largest of all aviation movement delays. However, taxi-out delays have not received attention equal to that focused on airborne delays because taxi-out delays often result from downstream problems. Also, until recently, there was no practical means of tracking surface movements. New surface surveillance technology will revolutionize...
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TCWF algorithm assessment - Memphis 2000
July 9, 2001
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-297
Summary
This report describes a formal Assessment of the Terminal Convective Weather Forecast (TCWF) algorithm, developed under the FAA Aviation Weather Research Program by MIT Lincoln Laboratory as part of the Convective Weather Product Development Team (PDT). TCWF is proposed as a Pre-Planned Product Improvement (P3I) enhancement to the operational ITWS currently scheduled for deployment at major airports in 2002. The TCWF Assessment in Memphis, TN ran from 24 March to 30 September 2000. The performance of TCWF was excellent on the large scale, organized storm systems it was designed to predict, and the software was extremely stable during the Assessment. Small changes to the algorithm parameters were made as a result of the 2000 testing. The TCWF performance can be improved on airmass storms and on forecasting new growth and subsequent decay of large-scale storms. These are active areas of research for future ITWS P3I builds.
Summary
This report describes a formal Assessment of the Terminal Convective Weather Forecast (TCWF) algorithm, developed under the FAA Aviation Weather Research Program by MIT Lincoln Laboratory as part of the Convective Weather Product Development Team (PDT). TCWF is proposed as a Pre-Planned Product Improvement (P3I) enhancement to the operational ITWS...
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The radar Correlation and Interpolation (C&I) algorithms deployed in the ASR-9 Processor Augmentation Card (9PAC)
June 29, 2001
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-299
Topic:
R&D area:
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Summary
The Airport Surveillance Radar 9 (ASR-9) is a terminal radar that was deployed by the Federal Aviation Administration (FAA) during the early 1990's at more than 130 of the busiest airports in the United States. The ASR-9 Processor Augmentation Card (9-PAC), developed at MIT Lincoln Laboratory, is a processor board enhancement for the ASR-9 Array Signal Processor (ASP) that provides increases in processing speed, memory size, and programming. The increased capabilities of the 9PAC hardware made it possible for new surveillance algorithms to be developed in software to provide improved primary radar and beacon surveillance performance. The 9PAC project was developed in two phases. Phase I, which addressed the beacon reflection false target problem, was completed, and is currently being deployed nationwide by the FAA on a plug and play basis. Phase II addresses the primary radar surveillance problems, which include automation of the road and ground clutter censoring process, improving the rejection of false targets, and improving the detection and tracking of aircraft targets. The 9PAC also reduces the life-cycle maintenance cost of the ASR-9 in the Phase II configuration, in which a single 9PAC card replaces four ASP cards. This report describes the improvements to the radar Correlation and Interpolation (C&I) process, which is responsible for creating aircraft target reports and filtering out false targets. [Not Complete]
Summary
The Airport Surveillance Radar 9 (ASR-9) is a terminal radar that was deployed by the Federal Aviation Administration (FAA) during the early 1990's at more than 130 of the busiest airports in the United States. The ASR-9 Processor Augmentation Card (9-PAC), developed at MIT Lincoln Laboratory, is a processor board...
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ASR-9 Processor Augmentation Card (9-PAC) phase II scan-scan correlator algorithms
April 26, 2001
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-298
Summary
This report documents the scan-scan correlator (tracker) algorithm developed for Phase II of the ASR-9 Processor Augmentation Card (9-PAC) project. The improved correlation and tracking algorithms in 9-PAC Phase II decrease the incidence of false-alarm tracks and increase the detection of real aircraft. The tracker processing for 9-PAC Phase II defined in this document builds upon the prototype 9-PAC Phase II tracker describedin ATC-245. Tracker algorithms from Mode S (ATC-65) are also used in Phase II. This document describes the three main processing tasks of the tracker: initialization, input/output, and the actual correlation/tracking. The tracker itself is further broken down into four main functions: report-to-track association, report-to-track correlation, track update, and track initiation. Each of these functions is described in detail and is further broken down into sub-functions. In addition to the algorithm descriptions, the 9-PAC Phase II tracker system requirements are reviewed, and main data structures used in the 9-PAC Phase II tracker are defined.
Summary
This report documents the scan-scan correlator (tracker) algorithm developed for Phase II of the ASR-9 Processor Augmentation Card (9-PAC) project. The improved correlation and tracking algorithms in 9-PAC Phase II decrease the incidence of false-alarm tracks and increase the detection of real aircraft. The tracker processing for 9-PAC Phase II...
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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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Positive charge in the stratiform cloud of a mesoscale convective system
January 16, 2001
Journal Article
Published in:
J. Geophys. Res., Vol. 106, No. D1, 16 January 2001, pp. 1157-1163.
Summary
A balloon sounding of electric field in the trailing stratiform cloud of a bow echo mesoscale convective system reveals only two substantial in-cloud positive charge regions. These charge regions are located at altitudes of 5.1-5.6 km and 6.4-6.8 km, above the level of 0 degree C at 4.2 km. The two positive charge regions are the likely sources of six positive cloud-to-ground flashes with large peak currents (>32 kA) that occurred within 60 km of the balloon during its flight. The amount of charge transferred by three of these positive flashes that made Q bursts is calculated in the range of 97-196 C. Flashes of this sort are known to produce sprites and elves in the mesosphere. The positive charge regions in this stratiform cloud are substantially lower than the 10-km altitude commonly assumed for the positive charge in many sprite modeling studies.
Summary
A balloon sounding of electric field in the trailing stratiform cloud of a bow echo mesoscale convective system reveals only two substantial in-cloud positive charge regions. These charge regions are located at altitudes of 5.1-5.6 km and 6.4-6.8 km, above the level of 0 degree C at 4.2 km. The...
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An assessment of the communications, navigation, surveillance (CNS) capabilities needed to support the future Air Traffic Management System
January 10, 2001
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-295
Topic:
R&D area:
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Summary
The purpose of this study was to assess the Communications, Navigation, and Surveillance (CNS) capabilities needed to support future Air Traffic Management (ATM) functionality in the National Airspace System (NAS). The goal was to determine the most effective areas for research and technical development in the CNS field and to make sure the decision support tools under development match future CNS capabilities. The requirements for future ATM functions were derived from high level operational concepts designed to provide more freedom and flexibility in flight operations and from the Joint Research Project Descriptions (JRPDs) that are listed in the Integrated Plan for Air Traffic Management Research and Technology Development. This work was performed for the FAA/NASA Interagency Air Traffic Management Integrated Product Team.
Summary
The purpose of this study was to assess the Communications, Navigation, and Surveillance (CNS) capabilities needed to support future Air Traffic Management (ATM) functionality in the National Airspace System (NAS). The goal was to determine the most effective areas for research and technical development in the CNS field and to...
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An operational concept for the Smart Landing Facility (SLF)
January 1, 2001
Conference Paper
Published in:
20th AIAA/IEEE Digital Avionics Systems Conf., 14-18 October 2001, pp. 6.C.2-1 - 6.C.2-8.
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Summary
This paper describes an operational concept for the Smart Landing Facility (SLF). The SLF is proposed as a component of the Small Aircraft Transportation System (SATS) and is envisioned to utilize Communication, Navigation, Surveillance and Air Traffic Management (CNS/ATM) technologies to support higher-volume air traffic operations in a wider variety of weather conditions than are currently possible at airports without an Air Traffic Control Tower (ATCT) or Terminal Radar Approach Control (TRACON). In order to accomplish this, the SLF will provide aircraft sequencing and separation within its terminal airspace (the SLF traffic area) and on the airport surface. The SLF infrastructure will provide timely and accurate weather and other flight information as well as traffic advisories. The SLF will provide a means to coordinate with nearby TRACONs or Air Route Traffic Control Centers (ARTCCs) to ensure proper integration of its traffic flows with those of adjacent airspace.
Summary
This paper describes an operational concept for the Smart Landing Facility (SLF). The SLF is proposed as a component of the Small Aircraft Transportation System (SATS) and is envisioned to utilize Communication, Navigation, Surveillance and Air Traffic Management (CNS/ATM) technologies to support higher-volume air traffic operations in a wider variety...
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