Publications
Tagged As
ASR-9 Weather Systems Processor technology refresh and upgrade
September 14, 2015
Conference Paper
Published in:
37th Conf. on Radar Meteorology, 14-18 September, 2015.
Topic:
R&D area:
Summary
The Weather Systems Processor (WSP) is an add-on system to the Airport Surveillance Radar-9 (ASR-9) that generates wind shear detection and storm tracking products for the terminal airspace. As the original system ages and pre-purchased replacement parts in the depot are used up, it becomes increasingly problematic to procure hardware components for repairs. Thus, a technical refresh is needed to sustain WSP operations into the future. This phase of the project targets the intermediate frequency digital receiver, the radar interface module, and the digital signal processor for replacement by updated hardware platforms. At the same time, the increase in computational capability allows for an upgrade in the signal processing algorithm, which will lead to data quality improvements.
Summary
The Weather Systems Processor (WSP) is an add-on system to the Airport Surveillance Radar-9 (ASR-9) that generates wind shear detection and storm tracking products for the terminal airspace. As the original system ages and pre-purchased replacement parts in the depot are used up, it becomes increasingly problematic to procure hardware...
READ MORE
Wind-shear detection performance analysis for MPAR risk reduction
September 16, 2013
Conference Paper
Published in:
36th Conf. on Radar Meteorology, 16 September 2013.
Topic:
R&D area:
R&D group:
Summary
Multifunction phased array radars (MPARs) of the future that may replace the current terminal wind-shear detection systems will need to meet the Federal Aviation Administration's (FAA) detection requirements. Detection performance issues related to on-airport siting of MPAR, its broader antenna beamwidth relative to the Terminal Doppler Weather Radar (TDWR), and the change in operational frequency from C band to S band are analyzed. Results from the 2012 MPAR Wind-Shear Experiment are presented, with microburst and gust-front detection statistics for the Oklahoma City TDWR and the National Weather Radar Testbed (NWRT) phased array radar, which are located 6 km apart. The NWRT has sensitivity and beamwidth similar to a conceptual terminal MPAR (TMPAR), which is a scaled-down version of a full-size MPAR. The micro-burst results show both the TDWR probability of detec-tion (POD) and the estimated NWRT POD exceeding the 90% requirement. For gust fronts, however, the overall estimated NWRT POD was more than 10% lower than the TDWR POD. NWRT data are also used to demonstrate that rapid-scan phased array radar has the potential to enhance microburst prediction capability.
Summary
Multifunction phased array radars (MPARs) of the future that may replace the current terminal wind-shear detection systems will need to meet the Federal Aviation Administration's (FAA) detection requirements. Detection performance issues related to on-airport siting of MPAR, its broader antenna beamwidth relative to the Terminal Doppler Weather Radar (TDWR), and...
READ MORE
Wind-shear detection performance study for multifunction phased array radar (MPAR) risk reduction
June 12, 2013
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-409
Summary
Multifunction phased array radars (MPARs) of the future that may replace the current terminal wind-shear detection systems will need to meet the Federal Aviation Administration's (FAA) detection requirements. Detection performance issues related to on-airport siting of MPAR, its broader antenna beamwidth relative to the TDWR, and the change in operational frequency from C band to S band are analyzed. Results from the 2012 MPAR Wind-Shear Experiment (WSE) are presented, with microburst and gust-front detection statistics for the Oklahoma City TDWR and the National Weather Radar Testbed (NWRT) phased array radar, which are located 6 km apart. The NWRT has sensitivity and beamwidth similar to a conceptual terminal MPAR (TMPAR), which is a scaled-down version of a full-size MPAR. The microburst results show both the TDWR probability of detection (POD) and the estimated NWRT POD exceeding the 90% requirement. For gust fronts, however, the overall estimated NWRT POD was more than 10% lower than the TDWR POD. NWRT data is also used to demonstrate that rapid-scan phased array radar has the potential to enhance microburst prediction capability.
Summary
Multifunction phased array radars (MPARs) of the future that may replace the current terminal wind-shear detection systems will need to meet the Federal Aviation Administration's (FAA) detection requirements. Detection performance issues related to on-airport siting of MPAR, its broader antenna beamwidth relative to the TDWR, and the change in operational...
READ MORE
Multifunction Phased Array Radar wind shear experiment
November 5, 2012
Conference Paper
Published in:
26th Conf. on Sever Local Storms, 5-8 November 2012.
Summary
Terminal Doppler Weather Radars (TDWRs) provide near-ground wind shear detection that is critical for aircraft safety at 46 airports across the United States. These systems are part of the larger network of 510 weather and aircraft surveillance radars owned and operated by government agencies in the continental United States. As the TDWR and other radar systems approach their engineering design life cycles, the Federal Aviation Administration (FAA), National Weather Service (NWS), and Department of Defense (DoD) are considering potential replacement systems (OFCM 2006; Weber et al. 2007). One option under consideration that would maintain the current airspace coverage is a replacement network of 334 Multifunction Phased Array Radars (MPARs) (Weber et al. 2007). The MPAR network described by Weber et al. (2007) would include two classes of systems: A high-resolution, full-scale version with an 8-m diameter antenna, and a lower-resolution terminal version with a 4-m diameter antenna, termed Terminal MPAR, or TMPAR. As the proposed TMPAR design has lower azimuthal beam resolution and less sensitivity than TDWRs, it is crucial to determine the impacts of that design on the detection of low-altitude wind shear. The design of the SPY-1A PAR, a research radar at the National Weather Radar Test Bed in Norman, Oklahoma (Zrnić et al. 2007), makes it a good proxy for examining the potential wind shear detection performance of the TMPAR. Therefore, in spring 2012, the National Oceanic and Atmospheric Administration (NOAA) National Severe Storms Laboratory organized and executed the MPAR Wind Shear Experiment (WSE) in collaboration with the FAA, NOAA's NWS Radar Operations Center, the University of Oklahoma Advanced Radar Research Center (OU ARRC), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT LL). The primary objective of the MPAR WSE was to collect low-altitude observations with the SPY-1A PAR (hereafter, PAR) for comparison with observations from the nearby Oklahoma City (OKC) TDWR. Of particular interest is comparison of MIT LL wind shear detection algorithm performance using data from these two radars; this analysis is reported in Cho et al. (2013). Data were also collected from other radars in central Oklahoma to facilitate basic research on microbursts and other wind-producing storms. This paper provides an overview of the MPAR WSE and observed wind shear events.
Summary
Terminal Doppler Weather Radars (TDWRs) provide near-ground wind shear detection that is critical for aircraft safety at 46 airports across the United States. These systems are part of the larger network of 510 weather and aircraft surveillance radars owned and operated by government agencies in the continental United States. As...
READ MORE
Analysis of ground-based radar low-altitude wind-shear detection in OEP terminal airspace for NextGen
December 2, 2010
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-375
Summary
To support the Next Generation Air Transportation System (NextGen), the Reduce Weather Impact Sensor RightSizing program is identifying and analyzing gaps in the current sensor network coverage relative to the Four-Dimensional Weather Data Cube Single Authoritative Source performance requirements. In this study, we look for shortfalls in low-altitude wind-shear sensing by ground-based radars and lidar in the NextGen super-density operations (SDO) terminal airspace. Specifically, 2D gridded wind-shear visibility (an upper bound to detection probability) data are generated for microbursts and gust fronts separately for different sensors, namely the Terminal Doppler Weather Radar, Next Generation Weather Radar, Airport Surveillance Radar-9 with Weather Systems Processor, and Doppler lidar.
Summary
To support the Next Generation Air Transportation System (NextGen), the Reduce Weather Impact Sensor RightSizing program is identifying and analyzing gaps in the current sensor network coverage relative to the Four-Dimensional Weather Data Cube Single Authoritative Source performance requirements. In this study, we look for shortfalls in low-altitude wind-shear sensing...
READ MORE
Redeployment of the New York TDWR - technical analysis of candidate sites and alternative wind shear sensors
September 14, 2009
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-351
Summary
The John F. Kennedy International Airport (JFK) and LaGuardia Airport (LGA) are protected from wind shear exposure by the New York Terminal Doppler Weather Radar (TDWR), which is currently located at Floyd Bennet Field, New York. Because of a September 1999 agreement between the Department of the Interior and the Department of Transportation, this location is required to be vacated no later than January 2023. Therefore, a study based on model simulations of wind shear detection probability was conducted to support future siting selection and alternative technologies. A total of 18 candidate sites were selected for analysis, including leaving the radar where it is. (The FAA will explore the feasibility of the latter alternative; it is included in this study only for technical analysis.) The 18 sites are: Six candidate sites that were identified in the initial New York TDWR site-survey studies in the 1990s (one of which is the current TDWR site), a site on Staten Island, two Manhattan skyscrapers, the current location of the WCBS Doppler weather radar in Twombly Landing, New Jersey, and eight local airports including JFK and LGA themselves. Results clearly show that for a single TDWR system, all six previously surveyed sites are suitable for future housing of the TDWR. Unfortunately, land acquisition of these sites will be at least as challenging as it was in the 1990s due to further urban development and likely negative reaction from neighboring residents. Evaluation results of the on-airport siting of the TDWR (either at JFK or at LGA) indicate that this option is feasible if data from the Newark TDWR are simultaneously used. This on-airport option would require software modification such as integration of data from the two radar systems an dimplementation of "overhead" feature detection. The radars on the Manhattan skyscrapers are not an acceptable alternative due to severe ground clutter. The Staten Island site and most other candidate airports are also not acceptable due to distance and/or beam blockage. The existing Airport Surveillance Radar (ASR-9) Weather Systems Processor (WSP) at JFK and the Bookhaven (OKX) Weather Surveillance Radar 1988-Doppler (WSR-88D, commonly known as NEXRAD) on Long Island cannot provide sufficient wind shear protection mainly due to limited wind shear detection capability and/or distance.
Summary
The John F. Kennedy International Airport (JFK) and LaGuardia Airport (LGA) are protected from wind shear exposure by the New York Terminal Doppler Weather Radar (TDWR), which is currently located at Floyd Bennet Field, New York. Because of a September 1999 agreement between the Department of the Interior and the...
READ MORE
Wind-shear system cost benefit analysis update
May 13, 2009
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-341
Summary
A series of fatal commercial aviation accidents in the 1970s led to the development of systems and strategies to protect against wind shear. The Terminal Doppler Weather Radar (TDWR), Low Level Wind Shear Alert System (LLWAS), Weather Systems Processor (WSP) for Airport Surveillance Radars (ASR-9), pilot training and on-board wind shear detection equipment are all key protection components. While these systems have been highly effective, there are substantial costs associated with maintaining and operating ground-based systems. In addition, while over 85% of all major air carrier operations occur at airports protected by one of these ground-based wind-shear systems, the vast majority of smaller operations remain largely unprotected. This report assesses the technical and operational benefits of current and potential alternative ground-based systems as mitigations for the low-altitude wind-shear hazard. System performance and benefits for all of the current TDWR (46), ASR-9 WSP (35), and LLWAS (40) protected airports are examined, along with 40 currently unprotected airports. We considered in detail several alternatives and/or combinations for existing ground-based systems. These included the option to use data from current WSR-88D (or NEXRAD) and two potential future sensor deployments: (1) a commercially built pulsed-Doppler Lidar and (2) an X-band commercial Doppler weather radar. Wind-shear exposure estimates and simulation models for each wind shear protection component were developed for each site in order to accurately comare all alternatives. For the period 2010-2032, the current combination of wind-shear protection systems reduces teh $3.0 billion unprotected NAS overall wind-shear safety exposure to just $160 million over the entire study period. Overall, tehre were few alternatives that resulted in higher benefits than the TDWR, TDWR-LLWAS, and WSP configurations that currently exist at 81 airports. However, the cheaper operating costs of NEXRAD make it a potential alternative especially at LLWAS and non-wind-shear protected sites.
Summary
A series of fatal commercial aviation accidents in the 1970s led to the development of systems and strategies to protect against wind shear. The Terminal Doppler Weather Radar (TDWR), Low Level Wind Shear Alert System (LLWAS), Weather Systems Processor (WSP) for Airport Surveillance Radars (ASR-9), pilot training and on-board wind...
READ MORE
Detection probability modeling for airport wind-shear sensors
September 15, 2008
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-340
Summary
An objective wind-shear detection probability estimation model is developed for radar, lidar, and sensor combinations. The model includes effects of system sensitivity, site-specific wind-shear, clutter, and terrain blockage characteristics, range-aliased obscuration statistics, antenna beam filling and attenuation, and signal processing differences which allow a sensor- and site-specific performance analysis of deployed and future systems. A total of 161 sites are analyzed for the study, consisting of airports currently serviced by the Terminal Doppler Weather Radar (TDWR) (46), Airport Surveillance Radar Weather Systems Processor (ASR-9 WSP) (35), Low Altitude Wind Shear Alert System-Relocation/Sustainment (LLWAS-RS) (40), and no wind-shear detection system (40). Sensors considered are the TDWR, WSP, LLWAS, Weather Surveillance Radar 1988-Doppler (WSR-88D, commonly known as NEXRAD), adn the Lockheed Martin Coherent Technologies (LMCT) Doppler lidar and proposed x-band radar. [not complete]
Summary
An objective wind-shear detection probability estimation model is developed for radar, lidar, and sensor combinations. The model includes effects of system sensitivity, site-specific wind-shear, clutter, and terrain blockage characteristics, range-aliased obscuration statistics, antenna beam filling and attenuation, and signal processing differences which allow a sensor- and site-specific performance analysis of...
READ MORE
Comparative analysis of terminal wind-shear detection systems
January 20, 2008
Conference Paper
Published in:
13th Conf. on Aviation, Range and Aerospace Meteorology, ARAM, 20-24 January 2008.
Topic:
R&D area:
R&D group:
Summary
Low-level wind shear, especially a microburst, is very hazardous to aircraft departing or approaching an airport. The danger became especially clear in a series of fatal commercial airliner accidents in the 1970s and 1980s at U.S. airports. In response, the Federal Aviation Agency (FAA) developed and deployed three ground-based low-altitude wind-shear detection systems: the Low Altitude Wind Shear Alert System (LLWAS) (Wilson and Gramzow 1991), the Terminal Doppler Weather Radar (TDWR) (Michelson et al. 1990), and the Airport Surveillance Radar Weather Systems Processor (ASR-9 WSP) (Weber and Stone 1995). Since the deployment of these sensors, commercial aircraft wind-shear accidents have dropped to near zero in the U.S. This dramatic decrease in accidents caused by wind shear appears to confirm the safety benefits provided by these detection systems. In addition, the broad area measurement capability of the TDWR and WSP provides ancillary delay reduction benefits, for example, by forecasting airport wind shifts that may require runway reconfiguration. The current deployment strategy for these various windshear detection systems is justified by an earlier integrated wind-shear systems cost-benefit analysis (Martin Marietta 1994). Since that time, conditions in the national airspace system (NAS) have evolved, such as the installation of onboard predictive wind-shear detection systems in an increasing number of aircraft, improved pilot training for wind-shear hazard identification, avoidance, and recovery, and further integration of observed wind-shear data into terminal weather systems. Given the tight fiscal environment at the FAA in recent years, the cost of maintaining the wind-shear detection systems has also become an issue. All systems require periodic service life extension programs (SLEPs). In light of these developments, the FAA has tasked MIT Lincoln Laboratory to provide an updated cost-benefit study on their terminal wind-shear detection systems. One of the key factors in estimating the benefits of a terminal wind-shear detection system is its performance. Thus, it is necessary to quantify the wind-shear detection probability for each sensor, preferably on an airport-by-airport basis. To consider sensors that are not yet deployed, a model must be developed that takes into account the various effects that factor into the detection probability. We have developed such a model. The focus of this paper is on this model and the results obtained with it.
Summary
Low-level wind shear, especially a microburst, is very hazardous to aircraft departing or approaching an airport. The danger became especially clear in a series of fatal commercial airliner accidents in the 1970s and 1980s at U.S. airports. In response, the Federal Aviation Agency (FAA) developed and deployed three ground-based low-altitude...
READ MORE
Analysis of operational alternatives to the Terminal Doppler Weather Radar (TDWR)
February 26, 2007
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-332
Summary
Possible alternatives to the Terminal Doppler Weather Radar (TDWR) are assessed. We consider both the low altitude wind shear detection service provided by TDWR and its role in reducing weather-related airport delays through its input to the Integrated Terminal Weather System (ITWS). Airborne predictive wind shear (PWS) radars do not provide the broad area situational awareness needed to proactively reroute aircraft away from the affected runways. We considered in detail the alternative of using the ASR-9 Weather Systems Processor (WSP) and NEXRAD in lieu of TDWR. An objective metric for wind shear detection capability was calculated for each of these radars at all TDWR equipped airports. TDWR was uniformly superior by this metric, and at a number of the airports, the ASR-9/NEXRAD alternative scored so low as to raise questions whether it would be operationally acceptable. To assess airport weather delay reduction impact, we compared the accuracy of the high-benefit ITWS "Terminal Winds" product with and without TDWR input. Removal of the TDWR data would have increased the mean estimate error by a factor of 3 near the surface.
Summary
Possible alternatives to the Terminal Doppler Weather Radar (TDWR) are assessed. We consider both the low altitude wind shear detection service provided by TDWR and its role in reducing weather-related airport delays through its input to the Integrated Terminal Weather System (ITWS). Airborne predictive wind shear (PWS) radars do not...
READ MORE