99-01 New NASA STI
Aug 17, 2008 -- Additions to the NASA scientific and technical information knowledge base
Title:
Analysis of a Dynamic Multi-Track Airway Concept for Air Traffic Management
Document ID:
20080026266
Report #:
NASA/TP-2008-215323, L-19462
Available Online:
http://hdl.handle.net/2060/20080026266
Sales Agency:
CASI Hardcopy A05 No Copyright
Author(s):
Wing, David J. (NASA Langley Research Center) Smith, Jeremy C. (NASA Langley Research Center) Ballin, Mark G. (NASA Langley Research Center)
Published:
20080701
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
94
Contract #:
None
Abstract:
The Dynamic Multi-track Airways (DMA) Concept for Air Traffic Management (ATM) proposes a network of high-altitude airways constructed of multiple, closely spaced, parallel tracks designed to increase en-route capacity in high-demand airspace corridors. Segregated from non-airway operations, these multi-track airways establish high-priority traffic flow corridors along optimal routes between major terminal areas throughout the National Airspace System (NAS). Air traffic controllers transition aircraft equipped for DMA operations to DMA entry points, the aircraft use autonomous control of airspeed to fly the continuous-airspace airway and achieve an economic benefit, and controllers then transition the aircraft from the DMA exit to the terminal area. Aircraft authority within the DMA includes responsibility for spacing and/or separation from other DMA aircraft. The DMA controller is responsible for coordinating the entry and exit of traffic to and from the DMA and for traffic flow management (TFM), including adjusting DMA routing on a daily basis to account for predicted weather and wind patterns and re-routing DMAs in real time to accommodate unpredicted weather changes. However, the DMA controller is not responsible for monitoring the DMA for traffic separation. This report defines the mature state concept, explores its feasibility and performance, and identifies potential benefits. The report also discusses (a) an analysis of a single DMA, which was modeled within the NAS to assess capacity and determine the impact of a single DMA on regional sector loads and conflict potential; (b) a demand analysis, which was conducted to determine likely city-pair candidates for a nationwide DMA network and to determine the expected demand fraction; (c) two track configurations, which were modeled and analyzed for their operational characteristic; (d) software-prototype airborne capabilities developed for DMA operations research; (e) a feasibility analysis of key attributes in the concept design; (f) a near-term, transitional application of the DMA concept as a proving ground for new airborne technologies; and (g) conclusions. The analysis indicates that the operational feasibility of a national DMA network faces significant challenges, especially for interactions between DMAs and between DMA and non-DMA traffic. Provided these issues are resolved, sectors near DMAs could experience significant local capacity benefits.
Language:
English
Title:
Role of Lidar Technology in Future NASA Space Missions
Document ID:
20080026269
Report #:
Paper-1076-K04-01
Available Online:
http://hdl.handle.net/2060/20080026269
Sales Agency:
CASI Hardcopy A02 No Copyright
Author(s):
Amzajerdian, Farzin (NASA Langley Research Center)
Published:
20080324
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
7
Contract #:
None
Abstract:
The past success of lidar instruments in space combined with potentials of laser remote sensing techniques in improving measurements traditionally performed by other instrument technologies and in enabling new measurements have expanded the role of lidar technology in future NASA missions. Compared with passive optical and active radar/microwave instruments, lidar systems produce substantially more accurate and precise data without reliance on natural light sources and with much greater spatial resolution. NASA pursues lidar technology not only as science instruments, providing atmospherics and surface topography data of Earth and other solar system bodies, but also as viable guidance and navigation sensors for space vehicles. This paper summarizes the current NASA lidar missions and describes the lidar systems being considered for deployment in space in the near future.
Language:
English
Notes:
Material Research Society (MRS) 2008 Spring Meet San Francisco, CA 24-28 Mar. 2008
Title:
Scintillation Breakdowns in Chip Tantalum Capacitors
Document ID:
20080029990
Report #:
None
Available Online:
http://hdl.handle.net/2060/20080029990
Sales Agency:
CASI Hardcopy A03 No Copyright
Author(s):
Teverovsky, Alexander (Perot Systems Corp.)
Published:
20080909
Source:
Perot Systems Corp. (Greenbelt, MD, United States)
Pages:
11
Contract #:
None
Abstract:
Scintillations in solid tantalum capacitors are momentarily local breakdowns terminated by a self-healing or conversion to a high-resistive state of the manganese oxide cathode. This conversion effectively caps the defective area of the tantalum pentoxide dielectric and prevents short-circuit failures. Typically, this type of breakdown has no immediate catastrophic consequences and is often considered as nuisance rather than a failure. Scintillation breakdowns likely do not affect failures of parts under surge current conditions, and so-called "proofing" of tantalum chip capacitors, which is a controllable exposure of the part after soldering to voltages slightly higher than the operating voltage to verify that possible scintillations are self-healed, has been shown to improve the quality of the parts. However, no in-depth studies of the effect of scintillations on reliability of tantalum capacitors have been performed so far. KEMET is using scintillation breakdown testing as a tool for assessing process improvements and to compare quality of different manufacturing lots. Nevertheless, the relationship between failures and scintillation breakdowns is not clear, and this test is not considered as suitable for lot acceptance testing. In this work, scintillation breakdowns in different military-graded and commercial tantalum capacitors were characterized and related to the rated voltages and to life test failures. A model for assessment of times to failure, based on distributions of breakdown voltages, and accelerating factors of life testing are discussed.
Language:
English
Notes:
Electronic Devices and Systems IMAPS CS International Conference Brno 10-11 Sep. 2008
99-02 New NASA STI Report Series
Aug 17, 2008 -- Additions to the NASA scientific and technical information knowledge base
Title:
Analysis of a Dynamic Multi-Track Airway Concept for Air Traffic Management
Document ID:
20080026266
Report #:
NASA/TP-2008-215323, L-19462
Available Online:
http://hdl.handle.net/2060/20080026266
Sales Agency:
CASI Hardcopy A05 No Copyright
Author(s):
Wing, David J. (NASA Langley Research Center) Smith, Jeremy C. (NASA Langley Research Center) Ballin, Mark G. (NASA Langley Research Center)
Published:
20080701
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
94
Contract #:
None
Abstract:
The Dynamic Multi-track Airways (DMA) Concept for Air Traffic Management (ATM) proposes a network of high-altitude airways constructed of multiple, closely spaced, parallel tracks designed to increase en-route capacity in high-demand airspace corridors. Segregated from non-airway operations, these multi-track airways establish high-priority traffic flow corridors along optimal routes between major terminal areas throughout the National Airspace System (NAS). Air traffic controllers transition aircraft equipped for DMA operations to DMA entry points, the aircraft use autonomous control of airspeed to fly the continuous-airspace airway and achieve an economic benefit, and controllers then transition the aircraft from the DMA exit to the terminal area. Aircraft authority within the DMA includes responsibility for spacing and/or separation from other DMA aircraft. The DMA controller is responsible for coordinating the entry and exit of traffic to and from the DMA and for traffic flow management (TFM), including adjusting DMA routing on a daily basis to account for predicted weather and wind patterns and re-routing DMAs in real time to accommodate unpredicted weather changes. However, the DMA controller is not responsible for monitoring the DMA for traffic separation. This report defines the mature state concept, explores its feasibility and performance, and identifies potential benefits. The report also discusses (a) an analysis of a single DMA, which was modeled within the NAS to assess capacity and determine the impact of a single DMA on regional sector loads and conflict potential; (b) a demand analysis, which was conducted to determine likely city-pair candidates for a nationwide DMA network and to determine the expected demand fraction; (c) two track configurations, which were modeled and analyzed for their operational characteristic; (d) software-prototype airborne capabilities developed for DMA operations research; (e) a feasibility analysis of key attributes in the concept design; (f) a near-term, transitional application of the DMA concept as a proving ground for new airborne technologies; and (g) conclusions. The analysis indicates that the operational feasibility of a national DMA network faces significant challenges, especially for interactions between DMAs and between DMA and non-DMA traffic. Provided these issues are resolved, sectors near DMAs could experience significant local capacity benefits.
Language:
English