Thesis (M.S.)--Oregon State University, 1988. / Typescript (photocopy). Includes bibliographical references (leaves 80-82). Also available on the World Wide Web.

Thesis (M.S.)--Rochester Institute of Technology, 2008. / Typescript. Includes bibliographical references (p. 239).

Project report (M. For.)--Virginia Polytechnic Institute and State University. M.S. 1993. / Abstract. Includes bibliographical references (leaves 32-62). Also available via the Internet.

The improved spatial resolution of the data from the SPOT satellite provides a substantially better basis for monitoring urban land use and growth with remote sensing than Landsat data. The purpose of this study is to delineate the road network in 20-m resolution SPOT-images of urban areas automatically. The roads appear as linear features. However, most edge and line detectors are not effective in detecting roads in these images because of the low signal to noise ratio, low contrast and blur in the imagery. For the automatic recognition of roads, a new line detector based on surface modelling is developed. A line can be approximated by a piecewise straight curve composed of short linear line-elements, called linels, each characterized by a direction, a length and a position. The approach to linel detection is to fit a directional surface that models the ideal local intensity profile of a linel in the least square sense. A Gaussian surface with a direction of invariance forms an adequate basis for modelling the ideal local intensity profile of the roads. The residual of the least squares fit as well as the parameters of the fit surface characterize the linel detected. The reliable performance of this line operator makes the problems of linking linels more manageable. / Master of Science

This Thesis deals with the national legal aspects of a particular space application: remote sensing by satellites, also referred to as earth observation systems. / Governments have been the leading providers and users of satellite imagery data since the advent of earth observation satellites (i.e. almost 40 years ago). However, this has changed, particularly in the United States, with several private companies having acquired and launched their own imaging satellite systems. This new trend towards commercialization and privatization of the remote sensing industry, which appeared firstly in the United States and which is now being extended to Canada, required a change in policy. The role played by the government policies and regulations in shaping the prospects for the emerging commercial remote sensing satellite firms is of critical importance. In this context, these policies and regulations will determine the conditions that will enable commercial firms to realize their competitive potential in both the domestic and international marketplace. / In this Thesis, a brief overview of the technical and historical legal backgrounds of remote sensing is provided. Then, the international legal framework of remote sensing is briefly analyzed. Finally, a thorough analysis of the policies, laws and regulations applicable within the United States and Canada is presented.

No description available.

No description available.

Cette thèse s’intéresse à la conception d’antennes ultra large bande reconfigurables. Cette étude a été motivée par le souhait de regrouper l’ensemble des antennes d’observation présentes sur les satellites en un panneau rayonnant unique afin de pouvoir réduire la taille de ces derniers. Les travaux présentés dans ce mémoire sont donc principalement axés sur la conception d’antennes spirales et sur les améliorations qui peuvent leur être apportées. Ainsi, une nouvelle topologie d’antenne spirale carrée reconfigurable en un réseau de quatre antennes spirales carrées plus petites sur la même ouverture rayonnante est exposée. Cette reconfiguration permet d’augmenter l’efficacité de surface de la structure tout en offrant de nouvelles possibilités d’utilisation à l’antenne et en améliorant ses performances. Les caractéristiques et les performances des deux configurations en états figés sont détaillées. Les maquettes réalisées et les résultats de mesure sont également présentés afin de valider le fonctionnement de l’antenne. Ensuite, différentes améliorations de cette structure sont présentées ainsi qu’une application possible. Enfin, une solution permettant d’améliorer le fonctionnement des antennes spirales imprimées au-dessus d’un plan de masse est décrite. En effet, cette solution permet de supprimer un nul de rayonnement lorsque l’antenne se situe à une demi-longueur d’onde du plan de masse. Sa bande passante d’utilisation peut ainsi être potentiellement doublée sans perdre la moitié de l’énergie comme avec l’utilisation d’absorbants. Cette technique consiste à ajouter un élément rayonnant parasite au-dessus de l’antenne. Cet élément est excité par couplage à l’antenne spirale et rayonne à la fréquence du nul de rayonnement. Cet élément étant faible bande, il ne dégrade pas le fonctionnement de l’antenne aux autres fréquences de la bande passante. Une structure utilisant ce concept a été réalisée afin de valider son fonctionnement. / This thesis focuses on the design of ultrawideband reconfigurable antennas. The objective of this study is to integrate all the antennas of observation on satellites into a single radiating panel and make it reconfigurable. Works presented in this document are focused on the design of spiral antennas and on their possible improvements. Thereby, a new topology of square spiral antenna reconfigurable into an array of four smaller square spiral antennas is shown. This reconfiguration allows increasing the surface efficiency of the structure while offering new possibilities of utilization to the antenna and improving its performance. Characteristics and performance of both configurations in frozen states are presented. Breadboards and measurements are also presented in order to validate the functioning of the antenna. Then, several improvements of this structure are studied and a possible application. Finally, a solution for improving the functioning of spiral antennas printed over a metallic ground plane is presented. This solution permits to remove a null of radiation when the distance between the antenna and the ground plane is a multiple of the half wavelength. In this way, its bandwidth can be doubled without losing the half of the energy like with absorbers. This technique consists in adding a parasitic radiating element over the antenna. This element is fed by coupling to the spiral antenna and radiates at the frequency of the null of radiation. This element is narrowband, so antenna performance remains unchanged at the other frequencies of the bandwidth. A structure using this concept has been made in order to validate its functioning.

Satellite technology represents the only technique for measuring sea surface temperatures (SSTs) on a global scale. SSTs are important as boundary conditions for climate and atmospheric boundary layer models which attempt to describe phenomena of all scales, ranging from local forecasts to predictions of global warming. Historical use of infrared satellite measurements for SST determination has been based on a theory which assumes that the atmosphere is 'thin', i.e., that atmospheric absorption of infrared radiation emitted from the sea surface has very little effect on the radiant intensity that is measured by satellites. However, a variety of independent radiative transfer models point to the possibility that the so-called 'thin approximation' is violated for humid atmospheres such as those found in the tropics, leading to errors in the retrieved SST that would be unacceptable to those who make use of such products. Furthermore, such tropical regions represent a significant portion of the globe, where coupled ocean-atmosphere disturbances can have global effects (e.g., the tropical Pacific El Nino-Southern Oscillation events). This study evaluates the thin approximation empirically, by combining radiative transfer theory and satellite data from the Eastern Atlantic ocean region studied during the Atlantic Statocumulus Transition Experiment (ASTEX). Six months of satellite data from May, June, and July of 1983 and 1984 are analyzed. To the degree that the data may be considered representative of globally valid relationships between measured variables, it is shown that the thin approximation is not appropriate for the tropics. This suggests that new methods are necessary for retrieving SSTs from the more humid regions of the globe. / Graduation date: 1993

Thesis (M.S. in Space Systems Operations)--Naval Postgraduate School, September 2003. / Thesis advisor(s): Richard Olsen, Richard Harkins. Includes bibliographical references (p. 43). Also available online.