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Preliminary weather information gap analysis for UAS operations, revision 1

November 2, 2017
  |
Project Report
Author:
Scot E. Campbell
…
Published in:
MIT Lincoln Laboratory Report ATC-437-REV-1
Topic:
weather
R&D area:
R&D group:

Summary

Unmanned Aircraft System (UAS) operations in the National Airspace System (NAS) are rapidly increasing. For example, 2017 has seen dramatically increased low altitude UAS usage for disaster relief and by first responders. The ability to carry out these operations, however, can be strongly impacted by adverse weather conditions. This report documents a preliminary quick-look identification and assessment of gaps in current weather decision support for UAS operations. An initial set of surveys and interviews with UAS operators identified 12 major gaps. These gaps were then prioritized based on the importance of the weather phenomena to UAS operations and the current availability of adequate weather information to UAS operators. Low altitude UAS operations are of particular concern. The lack of observations of ceiling, visibility, and winds near most low altitude UAS operational locations causes the validation of numerical weather forecasts of weather conditions for those locations to be the highest priority. Hazardous weather alerting for convective activity and strong surface winds are a major concern for UAS operations that could be addressed in part by access to existing FAA real time conventional aircraft weather products.
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Summary

Unmanned Aircraft System (UAS) operations in the National Airspace System (NAS) are rapidly increasing. For example, 2017 has seen dramatically increased low altitude UAS usage for disaster relief and by first responders. The ability to carry out these operations, however, can be strongly impacted by adverse weather conditions. This report...

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Preliminary weather information gap analysis for UAS operations, revision 1

Command and control for multifunction phased array radar

October 1, 2017
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Journal Article
Author:
Mark E. Weber
…
Published in:
IEEE Trans. Geosci. Remote Sens., Vol. 55, No. 10, October 2017, pp. 5899-5912.
Topic:
algorithms
R&D area:
R&D group:

Summary

We discuss the challenge of managing the Multifunction Phased Array Radar (MPAR) timeline to satisfy the requirements of its multiple missions, with a particular focus on weather surveillance. This command and control (C2) function partitions the available scan time among these missions, exploits opportunities to service multiple missions simultaneously, and utilizes techniques for increasing scan rate where feasible. After reviewing the candidate MPAR architectures and relevant previous research, we describe a specific C2 framework that is consistent with a demonstrated active array architecture using overlapped subarrays to realize multiple, concurrent receive beams. Analysis of recently articulated requirements for near-airport and national-scale aircraft surveillance indicates that with this architecture, 40–60% of the MPAR scan timeline would be available for the high-fidelity weather observations currently provided by the Weather Service Radar (WSR-88D) network. We show that an appropriate use of subarray generated concurrent receive beams, in concert with previously documented, complementary techniques to increase the weather scan rate, could enable MPAR to perform full weather volume scans at a rate of 1 per minute. Published observing system simulation experiments, human-in-the-loop studies and radar-data assimilation experiments indicate that high-quality weather radar observations at this rate may significantly improve the lead time and reliability of severe weather warnings relative to current observation capabilities.
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Summary

We discuss the challenge of managing the Multifunction Phased Array Radar (MPAR) timeline to satisfy the requirements of its multiple missions, with a particular focus on weather surveillance. This command and control (C2) function partitions the available scan time among these missions, exploits opportunities to service multiple missions simultaneously, and...

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Command and control for multifunction phased array radar

Development of a new inanimate class for the WSR-88D hydrometeor classification algorithm

August 31, 2017
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Conference Paper
Author:
James M. Kurdzo
…
Published in:
38th Conf. on Radar Meteorology, 27 August-1 September 2017.
Topic:
algorithms
R&D area:
R&D group:

Summary

The current implementation of the Hydrometeor Classification Algorithm (HCA) on the WSR-88D network contains two non-hydrometeor-based classes: ground clutter/anomalous propagation and biologicals. A number of commonly observed non-hydrometeor-based phenomena do not fall into either of these two HCA categories, but often are misclassified as ground clutter, biologicals, unknown, or worse yet, weather hydrometeors. Some of these phenomena include chaff, sea clutter, combustion debris and smoke, and radio frequency interference. In order to address this discrepancy, a new class (nominally named "inanimate") is being developed that encompasses many of these targets. Using this class, a distinction between non-biological and biological non-hydrometeor targets can be made and potentially separated into sub-classes for more direct identification. A discussion regarding the fuzzy logic membership functions, optimization of membership weights, and class restrictions is presented, with a focus on observations of highly stochastic differential phase estimates in all of the aforementioned targets. Recent attempts to separate the results into sub-classes using a support vector machine are presented, and examples of each target type are detailed. Details concerning eventual implementation into the WSR-88D radar product generator are addressed.
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Summary

The current implementation of the Hydrometeor Classification Algorithm (HCA) on the WSR-88D network contains two non-hydrometeor-based classes: ground clutter/anomalous propagation and biologicals. A number of commonly observed non-hydrometeor-based phenomena do not fall into either of these two HCA categories, but often are misclassified as ground clutter, biologicals, unknown, or worse...

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Development of a new inanimate class for the WSR-88D hydrometeor classification algorithm

Wind information requirements for NextGen operations, phase 5 report

August 22, 2017
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Project Report
Author:
Christopher Edwards
…
Published in:
MIT Lincoln Laboratory Report ATC-439
Topic:
air traffic control
R&D area:
R&D group:

Summary

NextGen applications with time-based control elements, such as required time of arrival (RTA) at a meter fix under 4D trajectory-based operations (4D-TBO)/time of arrival control (TOAC) procedures or assigned spacing goal between aircraft under Interval Management (IM) procedures, are subject to the quality of the atmospheric forecast utilized by participating aircraft. The work described in this report summarizes the major activities conducted in the current phase of this program which builds upon prior work. The major objectives were: 1. Support RTCA Special Committee-206 Aeronautical Information and Meteorological Data Link Services and co-chair a sub-group responsible for developing the document "Guidance for Data Linking Forecast and Real-Time Wind Information to Aircraft." 2. Analyze the performance of publicly available forecast as compared to in-situ reported atmospheric conditions, specifically comparing Global Forecast System (GFS) and High Resolution Rapid Refresh (HRRR) forecast data to recorded in-flight weather Meteorological Data Collection and Reporting System (MDCRS) data. 3. Analyze current and future Flight Management Systems (FMSs) to conduct operations at significantly lower altitudes than previous studies. 4. Evaluate potential sources of aircraft-derived winds to better support 4D-TBO activities. 5. Provide recommendations for high-value future work.
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Summary

NextGen applications with time-based control elements, such as required time of arrival (RTA) at a meter fix under 4D trajectory-based operations (4D-TBO)/time of arrival control (TOAC) procedures or assigned spacing goal between aircraft under Interval Management (IM) procedures, are subject to the quality of the atmospheric forecast utilized by participating...

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Wind information requirements for NextGen operations, phase 5 report

A new radio frequency interference filter for weather radars

July 1, 2017
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Journal Article
Author:
John Y. Cho
Published in:
J. Atmos. Ocean. Technol., Vol. 34, No. 7, 1 July 2017, pp. 1393-1406.
Topic:
algorithms
R&D area:
R&D group:

Summary

A new radio frequency interference (RFI) filter algorithm for weather radars is proposed in the two-dimensional (2D) range-time/sample-time domain. Its operation in 2D space allows RFI detection at lower interference-to-noise or interference-to-signal ratios compared to filters working only in the sample-time domain while maintaining very low false alarm rates. Simulations and real weather radar data with RFI are used to perform algorithm comparisons. Results are consistent with theoretical considerations and show the 2D RFI filter to be a promising addition to the signal processing arsenal against interference with weather radars. Increased computational burden is the only drawback relative to filters currently used by operational systems.
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Summary

A new radio frequency interference (RFI) filter algorithm for weather radars is proposed in the two-dimensional (2D) range-time/sample-time domain. Its operation in 2D space allows RFI detection at lower interference-to-noise or interference-to-signal ratios compared to filters working only in the sample-time domain while maintaining very low false alarm rates. Simulations...

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A new radio frequency interference filter for weather radars

Aircraft laser strike geolocation system

June 5, 2017
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Conference Paper
Author:
Erin M. Tomlinson
…
Published in:
17th AIAA Aviation Technology, Integration, and Operations Conf., 5-9 June 2017.
Topic:
detection systems
R&D area:
R&D group:

Summary

Laser strikes against aircraft are increasing at an alarming rate, driven by the availability of cheap powerful lasers and a lack of deterrence due to the challenges of locating and apprehending perpetrators. Although window coatings and pilot goggles effectively block laser light, uptake has been low due to high cost and pilot reluctance. This paper describes the development and testing of a proof-of-concept ground based sensor system to rapidly geolocate the origin of a laser beam in a protected region of airspace and disseminate this information to law enforcement to allow a timely and targeted response. Geolocation estimates with accuracies of better than 20 m have been demonstrated within 30 seconds of an event at a range of 8.9 nmi with a 450 mW laser. Recommendations for an operational prototype at an airport are also described.
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Summary

Laser strikes against aircraft are increasing at an alarming rate, driven by the availability of cheap powerful lasers and a lack of deterrence due to the challenges of locating and apprehending perpetrators. Although window coatings and pilot goggles effectively block laser light, uptake has been low due to high cost...

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Aircraft laser strike geolocation system

Report on the 2016 CoSPA and Traffic Flow Impact operational demonstration

June 1, 2017
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Project Report
Author:
Joseph C. Venuti
…
Published in:
MIT Lincoln Laboratory Report ATC-433
Topic:
weather
R&D area:
R&D group:

Summary

This technical report summarizes the operational observations recorded by MIT Lincoln Laboratory (MIT LL) aviation subject matter experts during the period 1 June to 31 October 2016. The MIT LL observation team visited three Federal Aviation Administration (FAA) Air Route Traffic Control Centers (ARTCC) and the Air Traffic Control System Command Center (ATCSCC) on three separate convective events covering four days during the summer of 2016. Five commercial airlines were also involved in the observations. Specifically noted were the utilization of the deterministic convective weather forecasting model, Storm Prediction for Aviation (CoSPA), and a newly developed decision support application, Traffic Flow Impact (TFI). These field evaluations were supported via the FAA AJM-334 program.
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Summary

This technical report summarizes the operational observations recorded by MIT Lincoln Laboratory (MIT LL) aviation subject matter experts during the period 1 June to 31 October 2016. The MIT LL observation team visited three Federal Aviation Administration (FAA) Air Route Traffic Control Centers (ARTCC) and the Air Traffic Control System...

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Report on the 2016 CoSPA and Traffic Flow Impact operational demonstration

Wind information requirements for NextGen applications phase 4 final report

March 6, 2017
  |
Project Report
Author:
Christopher Edwards
…
Published in:
MIT Lincoln Laboratory Report ATC-431
Topic:
weather
R&D area:
R&D group:

Summary

The success of many NextGen applications with time-based control elements, such as Required Time of Arrival (RTA) at a meter fix under 4D-Trajectory Based Operations (4D-TBO/Time of Arrival Control (TOAC) procedures or compliance to an Assigned Spacing Goal (ASG) between aircraft under Interval Management (IM) procedures, are subject to the quality of the atmospheric forecast utilized by participating aircraft. Erroneous information derived from provided forecast data, such as the magnitude of future headwinds relative to the headwinds actually experienced during flight, or forecast data that is insufficient to fully describe the forthcoming atmospheric conditions, can significantly degrade the performance of an attempted procedure. The work described in this report summarizes the major activities conducted in Fiscal Year 2015.
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Summary

The success of many NextGen applications with time-based control elements, such as Required Time of Arrival (RTA) at a meter fix under 4D-Trajectory Based Operations (4D-TBO/Time of Arrival Control (TOAC) procedures or compliance to an Assigned Spacing Goal (ASG) between aircraft under Interval Management (IM) procedures, are subject to the...

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Wind information requirements for NextGen applications phase 4 final report

WSR-88D chaff detection and characterization using an optimized hydrometeor classification algorithm

January 23, 2017
  |
Conference Paper
Author:
James M. Kurdzo
…
Published in:
18th Conf. on Aviation, Range, and Aerospace Meteorology, 23-26 January 2017.
Topic:
radar
R&D area:
R&D group:

Summary

Chaff presents multiple issues for aviation, air traffic controllers, and the FAA, including false weather identification and areas where flight paths may need to be altered. Chaff is a radar countermeasure commonly released from aircraft across the United States and is comprised of individual metallic strands designed to reflect certain wavelengths. Chaff returns tend to look similar to weather echoes in the reflectivity factor and radial velocity fields, and can appear as clutter, stratiform precipitation, or deep convection to the radar operator or radar algorithms. When polarimetric fields are taken into account, however, discrimination between weather and non-weather echoes has relatively high potential for success. In this work, the operational Hydrometeor Classification Algorithm (HCA) on the WSR-88D is modified to include a chaff class that can be used as input to a Chaff Detection Algorithm (CDA). This new class is designed using human-truthed chaff datasets for the collection and quantification of variable distributions, and the collected chaff cases are leveraged in the tuning of algorithm weights through the use of a metaheuristic optimization. A final CDA uses various image processing techniques to deliver a filtered output. A discussion regarding WSR-88D observations of chaff on a broad scale is provided, with particular attention given to observations of negative differential reflectivity during different stages of chaff fallout. Numerous cases are presented for analysis and characterization, both as an HCA class and as output from the filtered CDA.
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Summary

Chaff presents multiple issues for aviation, air traffic controllers, and the FAA, including false weather identification and areas where flight paths may need to be altered. Chaff is a radar countermeasure commonly released from aircraft across the United States and is comprised of individual metallic strands designed to reflect certain...

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WSR-88D chaff detection and characterization using an optimized hydrometeor classification algorithm

Terminal Flight Data Manager (TFDM) environmental benefits assessment

November 10, 2016
  |
Project Report
Author:
Thomas G. Reynolds
Published in:
MIT Lincoln Laboratory Report ATC-420
Topic:
air traffic control
R&D area:
R&D group:

Summary

This work monetizes the environmental benefits of Terminal Flight Data Manager (TFDM) capabilities which reduce fuel burn and gaseous emissions, and in turn reduce climate change and air quality effects. A methodology is created which takes TFDM "engines-on" taxi time savings and converts them to fuel and carbon dioxide (CO2) emissions savings, accounting for aircraft fleet mix at each of 27 TFDM analysis airports over a 2016-2048 analysis timeframe. Total fuel reductions of approximately 300 million U.S. gallons are estimated, resulting in monetized benefits from all TFDM capabilities of $65m-$582m undiscounted, $23m-$310m discounted, depending on the Social Cost of CO2 (SCC) and discount rate used. A similar methodology is used to estimate monetized benefits of reduced air quality emissions as well.
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Summary

This work monetizes the environmental benefits of Terminal Flight Data Manager (TFDM) capabilities which reduce fuel burn and gaseous emissions, and in turn reduce climate change and air quality effects. A methodology is created which takes TFDM "engines-on" taxi time savings and converts them to fuel and carbon dioxide (CO2)...

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Terminal Flight Data Manager (TFDM) environmental benefits assessment
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