Sparsity-Inducing Super-Resolution Passive Radar Imaging with Illuminators of Opportunity

Multiple illuminators of opportunity (IOs) and a large rotation angle are often required for current passive radar imaging techniques. However, a large rotation angle demands a long observation time, which cannot be implemented for actual passive radar system. To overcome this disadvantage, this paper proposes a super-resolution passive radar imaging framework with a sparsity-inducing compressed sensing (CS) technique, which allows for fewer IOs and a smaller rotation angle. In the proposed imaging framework, the sparsity-based passive radar imaging is modeled mathematically, and the spatial frequencies and amplitudes of different scatterers on the target are recovered by the log-sum penalty function-based CS reconstruction algorithm. In doing so, a super-resolution passive radar imagery is obtained by the frequency searching approach. Simulation results not only validate that the proposed method outperforms existing super-resolution algorithms, such as ESPRIT and RELAX, especially in the cases with low signal-to-noise ratio (SNR) and limited number of measurements, but also have shown that our proposed method can perform robust reconstruction no matter if the target is on grid or not

Sparsity-Inducing Super-Resolution Passive Radar Imaging with Illuminators of Opportunity

Multiple illuminators of opportunity (IOs) and a large rotation angle are often required for current passive radar imaging techniques. However, a large rotation angle demands a long observation time, which cannot be implemented for actual passive radar system. To overcome this disadvantage, this paper proposes a super-resolution passive radar imaging framework with a sparsity-inducing compressed sensing (CS) technique, which allows for fewer IOs and a smaller rotation angle. In the proposed imaging framework, the sparsity-based passive radar imaging is modeled mathematically, and the spatial frequencies and amplitudes of different scatterers on the target are recovered by the log-sum penalty function-based CS reconstruction algorithm. In doing so, a super-resolution passive radar imagery is obtained by the frequency searching approach. Simulation results not only validate that the proposed method outperforms existing super-resolution algorithms, such as ESPRIT and RELAX, especially in the cases with low signal-to-noise ratio (SNR) and limited number of measurements, but also have shown that our proposed method can perform robust reconstruction no matter if the target is on grid or not

Space station systems: A bibliography with indexes (supplement 6)

This bibliography lists 1,133 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1987 and December 31, 1987. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems. The coverage includes documents that define major systems and subsystems, servicing and support requirements, procedures and operations, and missions for the current and future Space Station

Metaphysics and the Moving Image

The various forms of cross-pollination and encounter between film and philosophy have generated thought experiments which make it possible to think beyond what the two fields can do for each other to what they can do together. My guiding intuition in this thesis is that the distinct historical evolutions of film and philosophy intersect in the speculative domain of the Western metaphysical paradigm, as the film medium technologically and aesthetically reestablishes conditions for “truth” within a contemporary intellectual climate which is often described as politically “post-truth.” As the long age of metaphysics comes to a close at the turn of the 19th century, ushered in by Nietzsche’s bold declaration “God is dead” and subjected thereafter to standardized modes of critique from both continental and analytical philosophic traditions, I explore how the emergence of film at this time and its representation of what André Bazin calls “the world in its own image” marks a migration of metaphysics from rational speculation through concepts to mechanical revelation through images and sounds. The rebirth of the world in its own image in the wake of the death of God is the self-affirmation of life and marks the first principle of a new "cine-metaphysics." I take seriously what appears as a mere historical coincidence (claiming that it is not a coincidence) and seek to analyze its implications for film-philosophy. With the birth of film following the death of God, I suggest that the world’s radical exposure and dramatic appearance onscreen and on its own terms, as it were, constitutes the basis not just for a continuation or return but rather a transformation of the philosophical tradition of metaphysics, rendering metaphysics “physical” and yielding a series of ontologically perspicuous figures of cinematic space-time brought to light by various aesthetic incarnations of the world in its own image. Through both theoretical and hermeneutic investigations into the metaphysical legacy of the moving image, one of my main conclusions is that in philosophy metaphysical thinking tends to result in conceptual abstraction or confusion, or is at least accused of such results, whereas cinema, conceived of as enacting the very object of metaphysical thought, can bring about the audiovisual clarity of the everyday