Three Dimensional Bistatic Tomography Using HDTV

The thesis begins with a review of the principles of diffraction and reflection tomography; starting with the analytic solution to the inhomogeneous Helmholtz equation, after linearization by the Born approximation (the weak scatterer solution), and arriving at the Filtered Back Projection (Propagation) method of reconstruction. This is followed by a heuristic derivation more directly couched in the radar imaging context, without the rigor of the general inverse problem solution and more closely resembling an imaging turntable or inverse synthetic aperture radar. The heuristic derivation leads into the concept of the line integral and projections (the Radon Transform), followed by more general geometries where the plane wave approximation is invalid. We proceed next to study of the dependency of reconstruction on the space-frequency trajectory, combining the spatial aperture and waveform. Two and three dimensional apertures, monostatic and bistatic, fully and sparsely sampled and including partial apertures, with controlled waveforms (CW and pulsed, with and without modulation) define the filling of k-space and concomitant reconstruction performance. Theoretical developments in the first half of the thesis are applied to the specific example of bistatic tomographic imaging using High Definition Television (HDTV); the United States version of DVB-T. Modeling of the HDTV waveform using pseudonoise modulation to represent the hybrid 8VSB HDTV scheme and the move-stop-move approximation established the imaging potential, employing an idealized, isotropic 18 scatterer. As the move-stop-move approximation places a limitation on integration time (in cross correlation/pulse compression) due to transmitter/receiver motion, an exact solution for compensation of Doppler distortion is derived. The concept is tested with the assembly and flight test of a bistatic radar system employing software-defined radios (SDR). A three dimensional, bistatic collection aperture, exploiting an elevated commercial HDTV transmitter, is focused to demonstrate the principle. This work, to the best of our knowledge, represents a first in the formation of three dimensional images using bistatically-exploited television transmitters

Remote Sensing of the Oceans

This book covers different topics in the framework of remote sensing of the oceans. Latest research advancements and brand-new studies are presented that address the exploitation of remote sensing instruments and simulation tools to improve the understanding of ocean processes and enable cutting-edge applications with the aim of preserving the ocean environment and supporting the blue economy. Hence, this book provides a reference framework for state-of-the-art remote sensing methods that deal with the generation of added-value products and the geophysical information retrieval in related fields, including: Oil spill detection and discrimination; Analysis of tropical cyclones and sea echoes; Shoreline and aquaculture area extraction; Monitoring coastal marine litter and moving vessels; Processing of SAR, HF radar and UAV measurements

COMBAT SYSTEMS Volume 1. Sensor Elements Part I. Sensor Functional Characteristics

This document includes: CHAPTER 1. SIGNATURES, OBSERVABLES, & PROPAGATORS. CHAPTER 2. PROPAGATION OF ELECTROMAGNETIC RADIATION. I. – FUNDAMENTAL EFFECTS. CHAPTER 3. PROPAGATION OF ELECTROMAGNETIC RADIATION. II. – WEATHER EFFECTS. CHAPTER 4. PROPAGATION OF ELECTROMAGNETIC RADIATION. III. – REFRACTIVE EFFECTS. CHAPTER 5. PROPAGATION OF ELECTROMAGNETIC RADIATION IV. – OTHER ATMOSPHERIC AND UNDERWATER EFFECTS. CHAPTER 6. PROPAGATION OF ACOUSTIC RADIATION. CHAPTER 7. NUCLEAR RADIATION: ITS ORIGIN AND PROPAGATION. CHAPTER 8. RADIOMETRY, PHOTOMETRY, & RADIOMETRIC ANALYSIS. CHAPTER 9. SENSOR FUNCTIONS. CHAPTER 10. SEARCH. CHAPTER 11. DETECTION. CHAPTER 12. ESTIMATION. CHAPTER 13. MODULATION AND DEMODULATION. CHAPTER 14. IMAGING AND IMAGE-BASED PERCEPTION. CHAPTER 15. TRACKING. APPENDIX A. UNITS, PHYSICAL CONSTANTS, AND USEFUL CONVERSION FACTORS. APPENDIX B. FINITE DIFFERENCE AND FINITE ELEMENT TECHNIQUES. APPENDIX C. PROBABILITY AND STATISTICS. INDEX TO VOLUME 1. Note by author: Note: Boldface entries in the table of contents are not yet completed

Ocean Remote Sensing with Synthetic Aperture Radar

The ocean covers approximately 71% of the Earth’s surface, 90% of the biosphere and contains 97% of Earth’s water. The Synthetic Aperture Radar (SAR) can image the ocean surface in all weather conditions and day or night. SAR remote sensing on ocean and coastal monitoring has become a research hotspot in geoscience and remote sensing. This book—Progress in SAR Oceanography—provides an update of the current state of the science on ocean remote sensing with SAR. Overall, the book presents a variety of marine applications, such as, oceanic surface and internal waves, wind, bathymetry, oil spill, coastline and intertidal zone classification, ship and other man-made objects’ detection, as well as remotely sensed data assimilation. The book is aimed at a wide audience, ranging from graduate students, university teachers and working scientists to policy makers and managers. Efforts have been made to highlight general principles as well as the state-of-the-art technologies in the field of SAR Oceanography

Electromagnetic characterization of barefaced terrain for oil sand exploration

The scant difference in the electromagnetic (EM) reflectivity of barefaced terrain often imposes challenges in differentiating between such terrain types and deployment of synthetic aperture radar to oil sand exploration. Microwave remote sensing has a proven ability to provide valuable information about targets. However to derive geoscientific information, a profound understanding of the EM interaction with terrain is vital. The challenge is to identify scattering characteristics relevant to oil sand fields. While various terrain identification methods and signature databases have been developed in the optical domain, only few examples of barefaced terrain discrimination in the microwave domain have been reported. In this thesis a three step multi-sensor approach has been used to identify EM signature of barefaced terrain encompassing homogeneous and heterogeneous materials, in the optical and microwave range. The combined method also led to the development of a large database of hyperspectral reflectivity, dielectric and backscattering data relevant to geointelligence analysis. The geochemical signature identification and prediction (GSIP) process required spectral data acquisition, chemometric model implementation and postprocessing to determine the spectral fingerprints and components of two strains of Nigerian oil sands. The results were compared with available hydrocarbon databases and four new features of Nigerian oil sands were observed. The dielectric discrimination statistical model (DDSM) involved three studies of the dielectric properties of oil sands and other barefaced terrain with different weight percentage of moisture and statistical processing of data to identify the 1 – 2 GHz and 5 – 7 GHz as most suitable frequency bands for microwave imaging. The GSIP and DDSM provided new empirical data on the geochemical and electrical behaviour of oil sand particularly the contrasting effects of bitumen, sand and moisture. Finally computer EM (CEM) models of barefaced terrain and sensors were used to identify the backscattering behaviour of the terrain for analysis in 2D/3D format. The results provided good agreement with classical surface roughness models particularly the Surface Perturbation and Kirchoffs Scattering model. They also enabled the investigation of the effect of wide variations in the sensor and terrain parameters on backscattering in order to evolve a radar signature necessary for identification of oil sand terrain for petroleum exploration. A laboratory scatterometer system (LSS) was developed and deployed in three imaging scenarios to verify aspects of the derived microwave EM signature of the terrain. The LSS measurements and the results from the CEMs were complimentary

Sensors, measurement fusion and missile trajectory optimisation

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

Processing of optic and radar images.Application in satellite remote sensing of snow, ice and glaciers

Ce document présente une synthèse de mes activités de recherche depuis la soutenance de ma thèse en 1999. L'activité rapportée ici est celle d'un ingénieur de recherche, et donc s'est déroulée en parallèle d'une activité ``technique'' comprenant des taches d'instrumentation en laboratoire, d'instrumentation de plateformes en montagne, de raids scientifiques sur les calottes polaires, d'élaboration de projets scientifiques, d'organisation d'équipes ou d'ordre administratif. Je suis Ingénieur de recherche CNRS depuis 2004 affecté au laboratoire Gipsa-lab, une unité mixte de recherche du CNRS, de Grenoble-INP, de l'université Joseph Fourier et de l'université Stendhal. Ce laboratoire (d'environ 400 personnes), conventionné avec l'INRIA, l'Observatoire de Grenoble et l'université Pierre Mendès France, est pluridisciplinaire et développe des recherches fondamentales et finalisées sur les signaux et les systèmes complexes.}Lors de la préparation de ma thèse (mi-temps 1995-99) au LGGE, je me suis intéressé au traitement des images de microstructures de la neige, du névé et de la glace. C'est assez naturellement que j'ai rejoint le laboratoire LIS devenu Gipsa-lab pour y développer des activités de traitement des images Radar à Synthèse d'Ouverture (RSO) appliqué aux milieux naturels neige, glace et glaciers. Etant le premier à générer un interférogramme différentiel des glaciers des Alpes, j'ai continué à travailler sur la phase interférométrique pour extraire des informations de déplacement et valider ces méthodes sur le glacier d'Argentière (massif du Mont-Blanc) qui présente l'énorme avantage de se déplacer de quelques centimètres par jour. Ces activités m'ont amené à développer, en collaboration avec les laboratoires LISTIC, LTCI et IETR, des méthodes plus générales pour extraire des informations dans les images RSO.Ma formation initiale en électronique, puis de doctorat en physique m'ont amené à mettre à profit mes connaissances en traitement d'images et des signaux, en électromagnétisme, en calcul numérique, en informatique et en physique de la neige et de la glace pour étudier les problèmes de traitement des images RSO appliqués à la glace, aux glaciers et à la neige

MF radar interferometry

This thesis describes the development, operation and observations of interferometry experiments on two medium frequency spaced antennae radar operated by the Department of Physics and Astronomy of the University of Canterbury; the 2.4 MHz radar at Birdlings Flat near Christchurch, New Zealand, and the 2.9 MHz radar at Scott Base on Ross Island in the Antarctic. These radars are of a standard design and detect scattering from the D and lower E regions of the ionosphere in the mesosphere and lower thermosphere. The interferometry techniques used were those of temporal, spatial and frequency domain interferometry which provide information on Doppler shifting and the directional and radial distribution of backscattered signals received by the radars. This project represents the first time that these techniques have been operated together on radars of the type used in this project. The techniques were also carried out in conjunction with the standard procedures used on these radars, that of Spaced Antennae Drifts with Full Correlation Analysis (FCA). Various forms of interferometric analyses were carried out and comparisons were made between the results of interferometric analyses and those of more conventional techniques. For example a study was made of the relationship between interferometric and FCA velocities in which it was found that there was good agreement between the two methods, particularly when the scattering region does not change rapidly as it moves. Other analysis techniques investigated included examination of the angular distribution of scattering and aspect sensitivity, the statistical distributions of scattered signals, post beam steering, vertical velocities and momentum fluxes. Frequency domain interferometry provided enhanced measurement of range and the scattering depth or distribution of range of scattered signals. Measurements of scattering depth clearly identified examples of thin layers or localized scatter. These localized scattering events appeared to be associated with either steady flow or long period variations in steady flow, for example with the semidiurnal solar tide. Aside from these events much of the scatter was observed to be anisotropic and also appeared to originate from a number of distributed scattering centres spread horizontally and vertically in a manner consistent with Fresnel scattering models