An Inertial Navigation System (INS) can individually produce the navigation data, i.e.position, velocity, of the aircraft without any help or aid. However, a large number of errors are ntroduced by sensors causing to an unacceptable drift in the output. Because of this reason, external aids are used to correct INS. Using these aids an integrated navigation structure is developed. In an integrated navigation system, INS output is used to alculate current navigation states / aid is used to supply external measurements and dierent algorithms are used to provide the most probable corrections to the state estimate using all data. One of the integrated navigation approaches is Terrain Aided Navigation (TAN). Terrain Aided Navigation is a technique to estimate the position of a moving vehicle by comparing the measured terrain profile under the vehicle to a stored map, DTED. This thesis describes the theoretical aspects implementation of a simulation environment, simulations of the implemented Kalman Filtering TAN algorithms with developed INS model. In order to perform the study, first a thorough survey of the literature on TAN navigation algorithms is performed. Then, we have developed a dynamics simulation environment. A flight profile generator is designed. Since, the main issue of this work is to correct INS, an Strapdown INS model developed using Matlab INS Toolbox. Therefore, to model a Strapdown INS, mathematical equations of INS system are derived and they are linearized to form linear error model. In addition, a radar altimeter simulator is also developed that provides measurement to the error dynamics. Then, a Kalman filter structure is designed and implemented using Matlab. The simulations are done with dierent linearization approaches using Kalman filter structure. Finally, the performance of the implemented algorithms are evaluated.

<p>Modern air battles are very dynamic and fast, and put extreme pressure on pilots. In some unpredictable situations, like new discovered threats or mission plan deviation because of enemy aircraft, the pilots might need to replan their predefined flight route. This is very difficult, if not impossible, to do since numerous factors affect it. A system that can help the pilots to do such a thing is needed. P</p><p>revious work in this field has involved methods from artificial intelligence like A*-search. In this master thesis, implementation of a replanning system based on a control theory method, Model Predictive Control (MPC), is examined. Different factors influencing the path, such as terrain and threats, are included in the algorithm. </p><p>The results presented in this thesis show that MPC solves the problem. As with every method there are some drawbacks and advantages, but as a summary the method is a very promising one and is worth further development. </p><p>Proposals of future work and different improvements of the algorithms used here are presented in this report as well.</p>

<p>There are occasions when it is preferable that an aircraft flies asclose to the ground as possible. It is difficult for a pilot to predict the topography when he cannot see beyond the next hill, and this makes it hard for him to find the optimal flight trajectory. With the help of a terrain database in the aircraft, the forthcoming topography can be found in advance and a flight trajectory can be calculated in real-time. The main goal is to find an optimal control sequence to be used by the autopilot. The optimization algorithm, which is created for finding the optimal control sequence, has to be run often and therefore, it has to be fast. </p><p>This thesis presents a terrain following algorithm based on Model Predictive Control which is a promising and robust way of solving the optimization problem. By using trajectory optimization, a trajectory which follows the terrain very good is found for the non-linear model of the aircraft.</p>

Ce travail se situe à l'intersection de deux champs de la recherche en éducation : les didactiques des sciences et les environnements informatiques pour l'apprentissage humain. Il s'inscrit dans un cadre socio-constructiviste et vise à identifier les conditions pour que des élèves puissent s'engager de manière autonome dans un travail d'investigation lors d'une classe de terrain en sciences de la Terre. <br />Nous développons l'idée que l'apprentissage des sciences s'appuie nécessairement sur la conduite d'une démarche d'investigation c'est-à-dire une démarche qui, dans le cadre de la résolution d'un problème, conduit à mettre en tension un modèle scientifique – considéré comme un outil « pour penser » - et un registre empirique constitué lors d'activités de terrain. Nous montrons également que la question de l'instrumentation est une question centrale et que l'intérêt de l'Environnement Informatique pour l'Apprentissage Humain (EIAH) que nous avons conçu réside dans le fait qu'il peut permettre de médiatiser les interactions, c'est-à-dire d'assister les élèves dans leur démarche d'investigation, et de permettre au professeur d'exercer un certain contrôle sur ce processus. Les environnements informatiques sont alors considérés comme des instruments qui sont construits par les apprenants au cours de leur activité et qui participent à la reconfiguration des processus d'apprentissage.

A model has been developed using the general-purpose Navier-Stokes solver CFX4 to simulate Atmospheric Boundary Layer flow over complex terrain. This model has been validated against the measured data from the Askervein Hill experiment, and has been shown to perform well. The CFD model is also compared to the WAsP linear model of wind flow over topography, and a significant improvement is noted for flow over complex topography. Boundary conditions, gridding issues and sensitivity to other solver parameters have all been investigated. An advanced roughness model has been developed to simulate flow over forest canopies, using a resistive body force within the canopy volume. The model is validated against measured data for simple 2D cases, and for a complex 3D case over real topography. The model is shown to give a more physically realistic profile for the wind speed in and just above forest canopies than the standard roughness length model used in most CFD simulations. An automated methodology for setting up CFD simulations using the models described has been developed. A custom pre-processing package to implement this has been written, to enable the use of the CFD methodology in a commercial environment.

Dans le contexte des réseaux complexes, la structure communautaire du réseau devient un sujet important pour plusieurs domaines de recherche. Les communautés sont en général vues comme des groupes intérieurement denses. La détection de tels groupes offre un éclairage intéressant sur la structure du réseau. Par exemple, une communauté de pages web regroupe des pages traitant du même sujet. La définition de communautés est en général limitée à une partition de l'ensemble des nœds. Cela exclut par définition qu'un nœd puisse appartenir à plusieurs communautés, ce qui pourtant est naturel dans de nombreux (cas des réseaux sociaux par exemple). Une autre question importante et sans réponse est l'étude des réseaux et de leur structure communautaire en tenant compte de leur dynamique. Cette thèse porte sur l'étude de réseaux dynamiques et la détection de communautés recouvrantes. Nous proposons deux méthodes différentes pour la détection de communautés recouvrantes. La première méthode est appelée optimisation de clique. L'optimisation de clique vise à détecter les nœds recouvrants granulaires. La méthode de l'optimisation de clique est une approche à grain fin. La seconde méthode est nommée détection floue (fuzzy detection). Cette méthode est à grain plus grossier et vise à identifier les groupes recouvrants. Nous appliquons ces deux méthodes à des réseaux synthétiques et réels. Les résultats obtenus indiquent que les deux méthodes peuvent être utilisées pour caractériser les nœds recouvrants. Les deux approches apportent des points de vue distincts et complémentaires. Dans le cas des graphes dynamiques, nous donnons une définition sur la relation entre les communautés à deux pas de temps consécutif. Cette technique permet de représenter le changement de la structure en fonction du temps. Pour mettre en évidence cette relation, nous proposons des diagrammes de lignage pour la visualisation de la dynamique des communautés. Ces diagrammes qui connectent des communautés à des pas de temps successifs montrent l'évolution de la structure et l'évolution des groupes recouvrantes., Nous avons également appliquer ces outils à des cas concrets.

Reljefo atvaizdavimas naudojamas geodezijoje, geoinformacinėse sistemose, kompiuteriniuose žaidimuose ir kitur. Dažniausiai išmatuoti reljefo duomenys nėra pakankamai tikslūs, ir su jais atvaizduojami paviršiai atrodo nenatūraliai. Šiame darbe aptariami trys pagrindiniai, viešai prieinami viso Žemės paviršiaus aukščių duomenų šaltiniai: GTOP30, ASTER GDEM ir SRTM. Nagrinėjami populiariausi reljefo interpoliavimo metodai tokie kaip bitiesinis, bikubinis, atvirkščiai proporcingo atstumo ir natūralių kaimynų. SRTM duomenų interaktyviai peržiūrai buvo sukurtas ArcGrid Viewer įrankis, leidžiantis peržiūrėti ArcGrid formatu išsaugotus reljefus. Interpoliavimo metodų tyrimui buvo sukurtas atskiras GeoSG įrankis. Su juo vienu metu galima stebėti kelis paviršius ir atlikti paviršių interpoliavimą bitiesiniu, bikubiniu, atvirkščiai proporcingo atstumo ir natūralių kaimynų metodais. Su šiuo įrankiu atliktas interpoliavimo metodų tikslumo įvertinimas. Nustatyta, kad geriausiai interpoliuoja bikubinis metodas, o blogiausiai – atvirkščiai proporcingo atstumo metodas. / Terrain rendering is used in geodesy, geographic information systems, computer games and other fields. Usually measured terrain data isn’t sufficiently precise, and if used for rendering, the result looks unnatural. This paper analyzes three main topographic data sources of planet Earth, that are publicly available: GTOP30, ASTER GDEM and SRTM. It compares the most often used methods for terrain data: bilinear, bicubic, inverse distance weighted and natural neighbor interpolation. To monitor SRTM data interactively an ArcGrid Viewer tool was created. It can be used to see terrain files in ArcGrid format. To study interpolation methods, a separate GeoSG tool was created. It can display several terrains at once and interpolate terrain data using bilinear, bicubic, inverse distance weighted and natural neighbor methods. This tool is used to evaluate interpolation methods. Results showed, that the best method for interpolation is the bicubic interpolation method, the worst – inverse distance weighted interpolation method.

Šiame darbe nagrinėjama panoraminio vaizdo tyrimo metodikos ir taikymo problematika. Aptariami pagrindiniai algoritmai naudojami ArcGIS programoje. Darbe pateikiama keletas pavyzdžių, kaip panoraminio vaizdo tyrimai taikant GIS programinę įrangą yra pritaikomi praktikoje. Antroje darbo dalyje yra atliekamas tyrimas, kurio tikslas išsiaiškinti, ar racionalu ir reikalinga būtų taikyti panoraminio matomumo tyrimus žemėlapyje, nekilnojamo turto reklama užsiimančiuose interneto puslapiuose. Tyrimo rezultatai atskleidžia, kad vietovės vaizdingumas yra svarbus veiksnys renkantis nekilnojamą turtą, o žmonės yra pasiruošę naudotis naujomis žemėlapio funkcijomis suteikiančiomis daugiau galimybių atliekant nekilnojamo turto vertinimą, tačiau panoraminio matomumo įrankio diegti į sistemas nerekomenduojama, dėl darbe aptariamų šios funkcijos trūkumų. Kita vertus autorius siūlo diegti naujas funkcijas, kurios pagerintų nešališką nekilnojamo turto vertinimą. / Work is developing the problem of methodology and applications of viewshed. Author is writing about main algorithms of this GIS function in ArcGIS program. Few practicable applications of viewshed are presented at work also. Item, some problems of these algorithms and applications of viewshed are developing. In second part of work author presents research about applications of viewshed for the internet web sites where is presented commercial of realty. The result consequent upon the research said that visibility is one of the main criterions of realty. Also Purchasers are ready for innovations of geographical information systems. On the other hands realty needs new GIS and mapping applications. In the conclusion of work author says that it is not worth to add the tool if viewshed to GIS systems to web pages of commercial of realty, because this tool have some problems for applications. On the other hand author suggests add some other functions to these maps which will improve neutral evaluation of realty.

Ecological land classification (ELC) is used to classify forest types in Ontario based on ecological gradients of soil moisture and nutrient fertility determined in the field. If ELC could be automated using terrain surfaces generated from airborne Light Detection and Ranging (LiDAR) remote sensing, it would enhance our ability to carry out forest ecosite classification and inventory over large areas. The focus of this thesis was to determine if LiDAR-derived terrain surfaces could be used to accurately quantify soil moisture in the boreal forest at a study site near Timmins, Ontario for use in ELC systems. Analysis was performed in three parts: (1) ecological land classification was applied to classify the forest plots based on soil texture, moisture regime and dominant vegetation; (2) terrain indices were generated at four different spatial resolutions and evaluated using regression techniques to determine which resolution best estimated soil moisture; and (3) ordination techniques were applied to separate the forest types based on biophysical field measurements of soil moisture and nutrient availability. The results of this research revealed that no single biophysical measurement alone could completely separate forest types; furthermore, the best LiDAR-derived terrain variables explained only 36.5% of the variation in the soil moisture in this study area. These conclusions suggest that species abundance data (i.e., indicator species) should be examined in tandem with biophysical field measurements and LiDAR data to improve classification accuracy. / Thesis (Master, Geography) -- Queen's University, 2010-12-16 18:52:04.81

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