37 research outputs found

    Performance of 3D PPN against arbitrarily maneuvering target for homing phase

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    The performance analysis of the 3-D pure proportional navigation (PPN) guidance law was traditionally conducted by considering the cross-coupling effect of two independent 2-D PPN laws in the pitch and yaw planes. This could increase the complexity of the analysis and lead to conservative analysis results, especially when the target has maneuverability. To mitigate this issue, this article theoretically analyzes the performance of 3-D PPN directly on a rotating engagement plane using a Lyapunov-like approach. Considering practical issues, the analysis includes not only capturability, but also upper-bounds of heading error, line-of-sight rate, commanded acceleration, and closing speed. The analysis results obtained are also demonstrated by using numerical simulation examples. Compared to the previous studies providing the least conservative results, the analysis procedure is significantly simplified and the results are proven to be more practical and less conservativ

    Sensors, measurement fusion and missile trajectory optimisation

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    When considering advances in “smart” weapons it is clear that air-launched systems have adopted an integrated approach to meet rigorous requirements, whereas air-defence systems have not. The demands on sensors, state observation, missile guidance, and simulation for air-defence is the subject of this research. Historical reviews for each topic, justification of favoured techniques and algorithms are provided, using a nomenclature developed to unify these disciplines. Sensors selected for their enduring impact on future systems are described and simulation models provided. Complex internal systems are reduced to simpler models capable of replicating dominant features, particularly those that adversely effect state observers. Of the state observer architectures considered, a distributed system comprising ground based target and own-missile tracking, data up-link, and on-board missile measurement and track fusion is the natural choice for air-defence. An IMM is used to process radar measurements, combining the estimates from filters with different target dynamics. The remote missile state observer combines up-linked target tracks and missile plots with IMU and seeker data to provide optimal guidance information. The performance of traditional PN and CLOS missile guidance is the basis against which on-line trajectory optimisation is judged. Enhanced guidance laws are presented that demand more from the state observers, stressing the importance of time-to-go and transport delays in strap-down systems employing staring array technology. Algorithms for solving the guidance twopoint boundary value problems created from the missile state observer output using gradient projection in function space are presented. A simulation integrating these aspects was developed whose infrastructure, capable of supporting any dynamical model, is described in the air-defence context. MBDA have extended this work creating the Aircraft and Missile Integration Simulation (AMIS) for integrating different launchers and missiles. The maturity of the AMIS makes it a tool for developing pre-launch algorithms for modern air-launched missiles from modern military aircraft.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Aerial Vehicles

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    This book contains 35 chapters written by experts in developing techniques for making aerial vehicles more intelligent, more reliable, more flexible in use, and safer in operation.It will also serve as an inspiration for further improvement of the design and application of aeral vehicles. The advanced techniques and research described here may also be applicable to other high-tech areas such as robotics, avionics, vetronics, and space

    The evolution of language: Proceedings of the Joint Conference on Language Evolution (JCoLE)

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    Shortest Route at Dynamic Location with Node Combination-Dijkstra Algorithm

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    Abstract— Online transportation has become a basic requirement of the general public in support of all activities to go to work, school or vacation to the sights. Public transportation services compete to provide the best service so that consumers feel comfortable using the services offered, so that all activities are noticed, one of them is the search for the shortest route in picking the buyer or delivering to the destination. Node Combination method can minimize memory usage and this methode is more optimal when compared to A* and Ant Colony in the shortest route search like Dijkstra algorithm, but can’t store the history node that has been passed. Therefore, using node combination algorithm is very good in searching the shortest distance is not the shortest route. This paper is structured to modify the node combination algorithm to solve the problem of finding the shortest route at the dynamic location obtained from the transport fleet by displaying the nodes that have the shortest distance and will be implemented in the geographic information system in the form of map to facilitate the use of the system. Keywords— Shortest Path, Algorithm Dijkstra, Node Combination, Dynamic Location (key words

    Report of the Secretary of War; being part of the message and documents communicated to the two Houses of Congress at the beginning of the third session of the Forty-sixth Congress, 1880

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    Annual Message to Congress with Documents; Pres. Hayes. 6 Dec. HED 1, 46-3, vl-12, 10,587p. [1951-1962) Indian education; Ute agreement; end of hostilities of the Apaches, and Sitting Bull\u27s band of Sioux; allotment; annual report of the Sec.of War (Serials 1952-1957); annual report of the Sec. of Interior (Serials 1959-1961); annual report of the Gen. Land Office (Serial 1959); annual report of the CIA (Serial 1959), including Indian police, railroads through Indian lands, invasion of Indian Territory, and reports of Supts. and agents; etc

    Aircraft-borne spectroscopic limb measurements of trace gases absorbing in the UV-A spectral range : investigations of bromine monoxide in the Arctic troposphere

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    Reactive halogen species (i.e., RHS=X, XO, X2, XY, OXO, HOX, XONO2, XNO2, with X,Y being I, Br and Cl) are known to be key compounds for the oxidation capacity of the troposphere, affecting the lifetime of relevant species such as O3, HOx, NOx, hydrocarbons, dimethylsulfide and gaseous elementary mercury. Furthermore, recent observations link iodine species to the formation of new aerosol particles. This work aims at the characterization of the abundance of BrO in the Arctic troposphere during the spring season, when the auto-catalytic release of bromine species from sea ice related halides is known to cause tropospheric Ozone Depletion Events (ODEs). A novel limb scanning mini-DOAS spectrometer for the detection of UV/vis absorbing radicals (e.g., O3, BrO, IO) was deployed on the DLR-Falcon (Deutsches Zentrum fĂŒr Luft- und Raumfahrt) aircraft and tested during a field campaign that took place at Svalbard (78°N) in spring 2007. Herein, a new algorithm for inferring concentration vertical profiles of tropospheric trace gases from aircraft-borne DOAS limb observations is presented, characterized and validated through the profile retrieval of the UV-A absorber O4. The method is then applied for retrieving tropospheric vertical profiles of BrO during the polar campaign. For deployments during ODEs, the retrieved BrO vertical profiles consistently indicate high BrO mixing ratios (~ 15 pptv) within the boundary layer, low BrO mixing ratios (< 1.5 pptv) in the free troposphere, occasionally enhanced BrO mixing ratios in the upper troposphere (~ 1.5 pptv), and increasing BrO mixing ratios with altitude in the lowermost stratosphere. These findings are well in agreement with satellite and balloon-borne soundings of total and partial BrO atmospheric column densities. Moreover, the capabilities of the aircraft-borne measurements are further exploited by analyzing the sources, photochemistry and transport processes of BrO in the boundary layer above the sea ice

    City of Pocatello v. Idaho Clerk\u27s Record v. 8 Dckt. 37723

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    https://digitalcommons.law.uidaho.edu/idaho_supreme_court_record_briefs/3719/thumbnail.jp
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