Publications
Wind information requirements to support Four Dimensional Trajectory-Based Operations
September 17, 2012
Conference Paper
Published in:
12th AIAA Aviation Technology, Integration, and Operations (ATIO) Conf. and 14th AIAA/ISSM, 17-19 September 2012.
Summary
Accurate wind information is required to support some of the key applications envisioned for future air traffic concepts. A Wind Information Analysis Framework is described to assess wind information needs for different applications. The framework is applied in a Four-Dimensional Trajectory Based Operations (4D-TBO) application using simplified versions of the framework's elements to demonstrate its utility. Realistic ranges of wind information accuracy limitations in terms of wind forecast and Flight Management System wind representation errors are studied. Their impacts on 4D-TBO performance in terms of Required Time of Arrival compliance and fuel burn are presented. Interpretations of the findings to determine wind information requirements are provided.
Summary
Accurate wind information is required to support some of the key applications envisioned for future air traffic concepts. A Wind Information Analysis Framework is described to assess wind information needs for different applications. The framework is applied in a Four-Dimensional Trajectory Based Operations (4D-TBO) application using simplified versions of the...
READ MORE
Establishing wind information needs for four dimensional trajectory-based operations
June 26, 2012
Conference Paper
Published in:
1st Int. Conf. on Interdisciplinary Science for Innovative Air Traffic Management, ISIATM, 26 June 2012.
Summary
Accurate wind information is of fundamental importance to the delivery of benefits from future air traffic concepts. A Wind Information Analysis Framework is described in this paper and its utility for assessing wind information needs for a four-dimensional trajectory based operations application is demonstrated.
Summary
Accurate wind information is of fundamental importance to the delivery of benefits from future air traffic concepts. A Wind Information Analysis Framework is described in this paper and its utility for assessing wind information needs for a four-dimensional trajectory based operations application is demonstrated.
READ MORE
CIWS product description, revision 1.0
April 30, 2010
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-355
Summary
Lincoln Laboratory has developed a set of information models for the encoding and distribution of data products from the National Corridor Integrated Weather System (CIWS) prototype, currently operating at Lincoln Laboratory in Lexington, Massachusetts. CIWS data products can be categorized as gridded and non-gridded. Gridded products are typically expressed as rectangular arrays whose elements contain a data value coinciding with uniformly-spaced observations or computed results on a 2-D surface. Gridded data arrays map to earth's surface through a map projection, for example, Lambert Conformal or Lambert Azimuthal Equal-Area. Non-gridded data products express observations or computed results associated with singular or sparsely distributed sets of geo-spatial locations such as points, curves, or contours. CIWS prototype data products were used to develop, refine, and evaluate reference information models for the CIWS gridded and non-gridded data. Data packaging methods were evaluated and selected on the basis of public-domain open-source availability and metadata support. Network Common Data Format (NetCDF), provided by Unidata, was selected as the information model for gridded CIWS products. For the non-gridded products, XML schemas have been developed along with sample XML instances to illustrate schema-compliant product encodings. These models follow and extend upon a number of Open Geospatial Consortium (OGC) and ISO standards including Geography Markup Language (GML), Observations and Measurements (OM), and Eurocontrol's Weather Exchange Model (WXXM). This document is intended to serve as a reference for the description of CIWS data product files.
Summary
Lincoln Laboratory has developed a set of information models for the encoding and distribution of data products from the National Corridor Integrated Weather System (CIWS) prototype, currently operating at Lincoln Laboratory in Lexington, Massachusetts. CIWS data products can be categorized as gridded and non-gridded. Gridded products are typically expressed as...
READ MORE
CSKETCH image processing library
August 21, 2002
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-283
Summary
The CSKETCH image processing library is a collection of C++ classes and global functions which comprise a development environment for meteorological algorithms. The library is best thought of as a 'tool-kit' which contains many standard mathematical and signal processing functions often employed in the analysis of weather radar data. A tutorial-style introduction to the library is given, complete with many examples of class and global function usage. Included is an in-depth look at the main class of the library, the SKArray class, which is a templatized and encapsulated class for storing numerical data arrays of one, two, or three dimensions. Following the tutorial is a complete reference for the library which describes all publicly-available class data members and class member functions, as well as all global functions included in the library.
Summary
The CSKETCH image processing library is a collection of C++ classes and global functions which comprise a development environment for meteorological algorithms. The library is best thought of as a 'tool-kit' which contains many standard mathematical and signal processing functions often employed in the analysis of weather radar data. A...
READ MORE
Gust front update algorithm for the Weather Systems Processor (WSP)
July 29, 2002
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-275
Summary
The Gust Front Update Algorithm (GFUP) is part of the gust front product generation chain for the ASR-9 Weather Systems Processor (WSP). GFUP processes gust front detection and position prediction data output by the Machine Intelligent Gust Front Algorithm (MIGFA), and uses an internal timer to schedule generation of updated current and 10- and 20-minute gust front predictions at 1-minute intervals. By substituting appropriate interval gust front forecast data from MIGFA, the locations of gust fronts shown on the user display are updated at a rate that is faster than the radar base data processed by MIGFA. Prior to output, the updated curve position data are smothered by GFUP using a tangent-spline interpolation algorithm. This document provides a general overview and high level description of the GFUP algorithm.
Summary
The Gust Front Update Algorithm (GFUP) is part of the gust front product generation chain for the ASR-9 Weather Systems Processor (WSP). GFUP processes gust front detection and position prediction data output by the Machine Intelligent Gust Front Algorithm (MIGFA), and uses an internal timer to schedule generation of updated...
READ MORE
Machine intelligent gust front algorithm for the WSP
June 10, 2002
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-274
Summary
The Machine Intelligent Gust Front Algorithm (MIGFA) utilizes multi-dimensional image processing and fuzzy logic techniques to identify gust fronts in Doppler radar data generated by the ASR-9 Weather Systems Processor (WSP). The algorithm generates products that support both safety and planning functions for ATC. Outputs include current and predicted locations of gust fronts, as well as estimates of the wind shear and wind shift associated with each gust front. This document provides both high level and detailed functional descriptions of FAA build 2.0 of the WSP MIGFA. The document was written with many explicit references to data structures and routines in the actual software in order that it may serve as a useful algorithm development and programmers reference guide.
Summary
The Machine Intelligent Gust Front Algorithm (MIGFA) utilizes multi-dimensional image processing and fuzzy logic techniques to identify gust fronts in Doppler radar data generated by the ASR-9 Weather Systems Processor (WSP). The algorithm generates products that support both safety and planning functions for ATC. Outputs include current and predicted locations...
READ MORE
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.
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...
READ MORE
Designing a terminal area bird detection and monitoring system based on ASR-9 data
August 27, 2001
Conference Paper
Published in:
3rd Joint Annual Meeting Bird Strike Committee, 27-30 August 2001.
Summary
Conflicts between birds and commercial aircraft are a noteworthy problem at both large and small airports [Cleary, 1999]. The risk factor for United States airports continues to increase due to the steady rise in take-off/landings and bird populations. There is a significant bird strike problem in the terminal area as shown by the incidents reported in the National Bird Strike Database [Cleary and Dolbeer, 1999]. The focus of bird strike mitigation in the past has centered primarily on wildlife management techniques. Recently, an Avian Hazard Advisory System (AHAS) has been developed to reduce the risks of bird strikes to military operations [Kelly, 1999]. This system uses a mosaic of data obtained from the Next Generation Weather Radar (NEXRAD). This sensor serves as an excellent tool for enroute bird advisories due to the radar coverage provided across the majority of the United States. However, its utility in the airport terminal environment is limited due to the slow update rate and the fact that the distance of most NEXRADs from the airport results in beam heights that are too high to detect low-altitude birds over the airport. The Federal Aviation Administration (FAA) operates two radar systems – the Terminal Doppler Weather Radar (TDWR), and the Airport Surveillance Radar (ASR-9) -- that could be used to help monitor bird activity at an airport in order to: 1. Provide continuously updated information on locations and approximate numbers of birds in flocks roosting or feeding on or near an airfield; 2. Generate real-time warnings of bird activity for dissemination to pilots of landing or departing aircraft by air traffic controllers or by direct data link. The TDWR provides wind shear warnings in the terminal area to enhance safety, while the ASR-9’s primary function is air traffic control. Both of these systems have been shown to detect biological echoes as well. Characteristics of the two radar systems have been examined and compared to determine capabilities for bird detection. Amongst other favorable factors, the high update rate and on-airport locale makes the ASR-9 a highly desirable platform for a bird detection and warning system for the terminal area. Data from an ASR-9 at Austin TX (AUS) equipped with a Weather Systems Processor (WSP) have been analyzed to assess the ASR-9's capability to detect and monitor bird activity. The WSP add-on provides a variety of radar base data products similar to those that would be available on all ASR-9s as part of an ASR-9 Service Life Extension Program (SLEP) currently underway. The Austin airport area is subject to large flocks of wintering migratory birds as well as a resident population of bats in close proximity to the airport. Radar data, visual observations and bird strike information during periods of active bird/bat movements have been collected for this study. An automated processing algorithm called the Terminal Avian Hazard Advisory System (TAHAS) is being developed to detect and track roosting and migratory birds using ASR-9 data. A key challenge will be the ability to discriminate biological from non-biological targets based on variables such as vertical continuity, variance or spectral width, and horizontal velocity distribution.
Summary
Conflicts between birds and commercial aircraft are a noteworthy problem at both large and small airports [Cleary, 1999]. The risk factor for United States airports continues to increase due to the steady rise in take-off/landings and bird populations. There is a significant bird strike problem in the terminal area as...
READ MORE
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...
READ MORE
ASR-9 Weather Systems Processor (WSP): wind shear algorithms performance assessment
November 13, 1996
Conference Paper
Published in:
Workshop on Wind Shear and Wind Shear Alert Systems,. Oklahoma City, 13-15 November, 1996.
Summary
Under Federal Aviation Administration sponsorship, Lincoln Laboratory has developed a prototype Airport Surveillance Radar Weather Systems Processor (ASR-WSP). This prototype has been used for field measurements and operational demonstrations since 1987. Measurements so acquired provide an extensive database for development and validation of the algorithms used by the WSP to generate operational wind shear information for Air Traffic Controllers. In this paper we assess the performance of the current versions of the WSP's microburst and gust front wind shear detection algorithms on data from each of the locations at which our prototype system has operated. Evaluation of the associated environmental characteristics (e.g., storm structure, radar ground clutter environment) allows for generalization of these results to the major U.S. climatic regimes where the production version of WSP will be deployed.
Summary
Under Federal Aviation Administration sponsorship, Lincoln Laboratory has developed a prototype Airport Surveillance Radar Weather Systems Processor (ASR-WSP). This prototype has been used for field measurements and operational demonstrations since 1987. Measurements so acquired provide an extensive database for development and validation of the algorithms used by the WSP to...
READ MORE