8 research outputs found

    New Pose Estimation Methodology for Target Tracking and Identification

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    Ground Moving Target Indicator (GMTI) and High Resolution Radar (HRR) can track position and velocity of ground moving target. Pose, angle between position and velocity, can be derived from kinematics estimates of position and velocity and it is often used to reduce the search space of a target identification (ID) and Automatic Target Recognition (ATR)聽 algorithms. Due to low resolution in some radar systems, the GMTI estimated pose may exhibit large errors contributing to a faulty identification of potential targets. Our goal is to define new methodology to improve pose estimate. Besides applications in target tracking, there are numerous commercial applications in machine learning, augmented reality and body tracking

    Automatic Target Recognition for Hyperspectral Imagery

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    Automatic target detection and recognition in hyperspectral imagery offer passive means to detect and identify anomalies based on their material composition. In many combat identification approaches through pattern recognition, a minimum level of confidence is expected with costs associated with labeling anomalies as targets, non-targets or out-of-library. This research approaches the problem by developing a baseline, autonomous four step automatic target recognition (ATR) process: 1) anomaly detection, 2) spectral matching, 3) out-of-library decision, and 4) non-declaration decision. Atmospheric compensation techniques are employed in the initial steps to compare truth library signatures and sensor processed signatures. ATR performance is assessed and additionally contrasted to two modified ATRs to study the effects of including steps three and four. Also explored is the impact on the ATR with two different anomaly detection methods

    Ballistic Flash Characterization: Penetration and Back-face Flash

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    The Air Force is extremely concerned with the safety of its people, especially those who are flying aircraft. Aircrew members flying combat missions are concerned with the chance that a fragment from an exploding threat device may penetrate into the airframe to possibly ignite a fire onboard the aircraft. One concern for vulnerability revolves around a flash that may occur when a projectile strikes and penetrates an aircraft\u27s fuselage. When certain fired rounds strike the airframe, they break into fragments called spall. Spall and other fragmentation from an impact often gain enough thermal energy to oxidize the materials involved. This oxidation causes a flash. To help negate these incidents, analysts must be able to predict the flash that can occur when a projectile strikes an aircraft. This research directly continues AFIT work for the 46th Test Group, Survivability Analysis Flight, by examining models to predict the likelihood of penetration of a fragment fired at a target. Empirical live-fire fragment test data are used to create an empirical model of a flash event. The resulting model provides an initial back-face flash modeling capability that can be implemented in joint survivability analysis models

    Subspace-based methodologies for the non-cooperative identification of aircraft by means of a synthetic database of radar signatures

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    Una de las principales preocupaciones dentro del mundo de la aviaci贸n es la identificaci贸n r谩pida, eficaz y fiable de cualquier objeto observado que se encuentre a cualquier distancia y bajo cualquier condici贸n atmosf茅rica. Gracias a los avances en tecnolog铆a radar, esto se ha conseguido. De hecho, los radares son los sensores m谩s adecuados para el reconocimiento de blancos en vuelo ya que pueden operar en cualquier condici贸n. El reconocimiento de blancos mediante radar es hoy un hecho, existiendo sistemas IFF (Identification Friend or Foe) capaces de comunicarse con una aeronave haciendo posible que ella misma se identifique por s铆 sola. Sin embargo, esta necesidad de comunicaci贸n directa puede ser un inconveniente en ciertos momentos. As铆, aparecen las t茅cnicas no cooperativas o NCTI (Non-Cooperative Target Identification), que no establecen ninguna comunicaci贸n con el blanco y normalmente hacen uso de radares de alta resoluci贸n. 脡stos ven los blancos como compuestos por diversos puntos que dispersan la energ铆a emitida por el radar, generando as铆 una imagen de la reflectividad de un blanco, lo que se ha llamado su firma radar. Comparando dicha firma radar con una base de datos de firmas radar de blancos conocidos es posible establecer, mediante una serie de algoritmos de identificaci贸n, el tipo de blanco iluminado por el radar. Uno de los temas m谩s cuestionados es c贸mo poblar y actualizar esta base de datos de firmas radar. De manera ideal, la base de datos deber铆a de contener medidas de blancos reales en vuelo; desafortunadamente, la principal desventaja de esta estrategia radica en la dificultad de obtener firmas radar de aviones neutrales o enemigos. Por esta raz贸n, esta tesis propone utilizar firmas radar de blancos ideales, generadas mediante simulaciones electromagn茅ticas, como base de datos. Con el avance de las herramientas de predicci贸n electromagn茅tica es posible obtener de manera r谩pida y a bajo coste firmas radar de cualquier blanco deseado y en cualquier orientaci贸n. De este modo, el principal objetivo de esta tesis yace en el desarrollo de algoritmos eficientes de identificaci贸n de aeronaves en vuelo de manera no cooperativa, con altas tasas de acierto y empleando una base de datos de blancos obtenida mediante simulaci贸n electromagn茅tica. El escenario propuesto consiste en la comparaci贸n de firmas radar reales obtenidas en una campa帽a de medidas con una base de datos compuesta por firmas radar simuladas, con ello se pretende por un lado, simular un escenario m谩s realista, en el que las firmas de los blancos recogidas por el radar no tienen porqu茅 tener la misma calidad que aquellas de la base de datos y por otro, comprobar que la identificaci贸n de un avi贸n real mediante simulaciones es posible

    Removal of antagonistic spindle forces can rescue metaphase spindle length and reduce chromosome segregation defects

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    Regular Abstracts - Tuesday Poster Presentations: no. 1925Metaphase describes a phase of mitosis where chromosomes are attached and oriented on the bipolar spindle for subsequent segregation at anaphase. In diverse cell types, the metaphase spindle is maintained at a relatively constant length. Metaphase spindle length is proposed to be regulated by a balance of pushing and pulling forces generated by distinct sets of spindle microtubules and their interactions with motors and microtubule-associated proteins (MAPs). Spindle length appears important for chromosome segregation fidelity, as cells with shorter or longer than normal metaphase spindles, generated through deletion or inhibition of individual mitotic motors or MAPs, showed chromosome segregation defects. To test the force balance model of spindle length control and its effect on chromosome segregation, we applied fast microfluidic temperature-control with live-cell imaging to monitor the effect of switching off different combinations of antagonistic forces in the fission yeast metaphase spindle. We show that spindle midzone proteins kinesin-5 cut7p and microtubule bundler ase1p contribute to outward pushing forces, and spindle kinetochore proteins kinesin-8 klp5/6p and dam1p contribute to inward pulling forces. Removing these proteins individually led to aberrant metaphase spindle length and chromosome segregation defects. Removing these proteins in antagonistic combination rescued the defective spindle length and, in some combinations, also partially rescued chromosome segregation defects. Our results stress the importance of proper chromosome-to-microtubule attachment over spindle length regulation for proper chromosome segregation.postprin

    Psr1p interacts with SUN/sad1p and EB1/mal3p to establish the bipolar spindle

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    Regular Abstracts - Sunday Poster Presentations: no. 382During mitosis, interpolar microtubules from two spindle pole bodies (SPBs) interdigitate to create an antiparallel microtubule array for accommodating numerous regulatory proteins. Among these proteins, the kinesin-5 cut7p/Eg5 is the key player responsible for sliding apart antiparallel microtubules and thus helps in establishing the bipolar spindle. At the onset of mitosis, two SPBs are adjacent to one another with most microtubules running nearly parallel toward the nuclear envelope, creating an unfavorable microtubule configuration for the kinesin-5 kinesins. Therefore, how the cell organizes the antiparallel microtubule array in the first place at mitotic onset remains enigmatic. Here, we show that a novel protein psrp1p localizes to the SPB and plays a key role in organizing the antiparallel microtubule array. The absence of psr1+ leads to a transient monopolar spindle and massive chromosome loss. Further functional characterization demonstrates that psr1p is recruited to the SPB through interaction with the conserved SUN protein sad1p and that psr1p physically interacts with the conserved microtubule plus tip protein mal3p/EB1. These results suggest a model that psr1p serves as a linking protein between sad1p/SUN and mal3p/EB1 to allow microtubule plus ends to be coupled to the SPBs for organization of an antiparallel microtubule array. Thus, we conclude that psr1p is involved in organizing the antiparallel microtubule array in the first place at mitosis onset by interaction with SUN/sad1p and EB1/mal3p, thereby establishing the bipolar spindle.postprin
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