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Full-Text Articles in Engineering
Navigation And Position Determination With A Multicarrier Modulation Signal Of Opportunity, Richard K. Martin, Jamie S. Velotta, John F. Raquet
Navigation And Position Determination With A Multicarrier Modulation Signal Of Opportunity, Richard K. Martin, Jamie S. Velotta, John F. Raquet
AFIT Patents
A multicarrier modulation position determination method that includes deploying at least one known receiver with a known location and a second receiver with an unknown location. At least two signals of opportunity with different locations are obtained by both the receiver and the second receiver. The signals having a plurality of block data, the block data having block boundaries. The block boundaries including a beginning block boundary and an end block boundary. The block data further including a cyclic prefix at the beginning block boundary. Acquiring a plurality of data samples for at least a portion of the block data …
Precision Position, Navigation, And Timing Without The Global Positioning System, Kenneth A. Fisher, John F. Raquet
Precision Position, Navigation, And Timing Without The Global Positioning System, Kenneth A. Fisher, John F. Raquet
Faculty Publications
The NAVSTAR Global Positioning System GPS has revolutionized modern warfare. Since 2005 almost all US precision-guided munitions have used GPS targeting data. Consequently, weapons delivery systems are able to strike enemy targets with precision, often resulting in little or no collateral damage. Furthermore, nearly all military assets, including aircraft, tanks, ships, missiles, mortar rounds, cargo boxes, and dismounted Soldiers rely on the accurate position determination that GPS provides. For military users of this system, two main limitations emerge. First, the system relies on line of sight that is, the satellites must be in view of the receiver s antenna so …
Airplane Landing Flare-The Last 5 Seconds, Nihad E. Daidzic
Airplane Landing Flare-The Last 5 Seconds, Nihad E. Daidzic
Aviation Department Publications
No abstract provided.
Some Considerations For Regional Airline Operations On Contaminated Runways., Nihad E. Daidzic
Some Considerations For Regional Airline Operations On Contaminated Runways., Nihad E. Daidzic
Aviation Department Publications
No abstract provided.
Modeling And Control Of Space Vehicles With Fuel Slosh Dynamics, Mahmut Reyhanoglu
Modeling And Control Of Space Vehicles With Fuel Slosh Dynamics, Mahmut Reyhanoglu
Physical Sciences - Daytona Beach
"Ever since the launch of the early high-efficiency rockets, controlling liquid fuel slosh within a launch vehicle has been a major design concern. Moreover, with today's large and complex spacecraft, a substantial mass of fuel is necessary to place them into orbit and to perform orbital maneuvers."--from the book's introduction
Terminal Guidance Of Autonomous Parafoils In High Wind-To-Airspeed Ratios, Nathan Slegers, O A. Yakimenko
Terminal Guidance Of Autonomous Parafoils In High Wind-To-Airspeed Ratios, Nathan Slegers, O A. Yakimenko
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
Autonomous precision placement of parafoils is challenging because of their limited control authority and sensitivity to winds. In particular, when wind speed is near the airspeed, guidance is further complicated by the parafoils inability to penetrate the wind. This article specifically addresses the terminal phase and develops an approach for generating optimal trajectories in real-time based on the inverse dynamics in the virtual domain. The method results in efficient solution of a two-point boundary-value problem using only a single optimization parameter allowing the trajectory to be generated at a high rate, mitigating effects of the unknown winds. It is shown …
Tethered Aerostat Modeling Using An Efficient Recursive Rigid-Body Dynamics Approach, Brad Hembree, Nathan Slegers
Tethered Aerostat Modeling Using An Efficient Recursive Rigid-Body Dynamics Approach, Brad Hembree, Nathan Slegers
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
A tethered aerostat model is developed using a computationally efficient recursive tether model. The recursive rigid-body tether model results in unconstrained ordinary differential equations and maintains much of the simplicity of simple lumped-mass tether models, while avoiding numerical difficulties associated with using many stiff elastic elements with low mass. Further efficiency is achieved by treating each tether link as a body of revolution and assuming that tether spin is negligible to the dynamics. The tether is attached to a six-degree-of-freedom aerostat model using a single viscoelastic element. The final recursive tethered aerostat model is well suited for a variety of …