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Helicopters are essential for any mission of humanitarian or assisting nature in disaster areas. Very often they have to cope with missing infrastructure and extreme environmental conditions. Besides darkness and adverse weather, dust and snow are two of the most dangerous conditions for helicopter landing. At the time being, helicopter pilots have no adequate sensors to get information on height...
Synthetic aperture radar (SAR) is active and coherent microwave high resolution imaging system, which has the capability to image in all weather and day-night conditions. SAR transmits chirp signals and the received echoes are sampled into In-phase (I) and Quadrature (Q) components, generally referred to as raw SAR data. Raw data compression is an essential future requirement for high resolution space...
In this paper, ground penetrating radar and tomography are combined to detect and identify hidden targets, such as underground facilities and hard and deeply buried targets. Past experience in below-ground imaging is described, current measurement results are presented, and future plans are discussed.
Cross-correlation based image subtraction for detection of targets within an urban structure from synthetic aperture radar images is presented. In surveillance operations requiring re-imaging of the same scene, small displacements in array element locations may cause large phase and amplitude offsets. Subsequently, clutter will not cancel out, but will rather persist when subtracting two images, one...
A stylized compressed sensing radar is proposed in which the time-frequency plane is discretized into an N by N grid. Assuming that the number of targets K is small (i.e. KLtN2), then we can transmit a sufficiently ldquoincoherentrdquo pulse and employ the techniques of compressed sensing to reconstruct the target scene. A theoretical upper bound on the sparsity K is presented. Numerical simulations...
The fractal geometry proved to be the most appropriate mathematical instrument in describing natural scenes, by means of few effective and reliable geophysical parameters. In this paper we describe a complete processing chain for the retrieving of SAR image fractal parameters and for change detection purposes. We present an overall framework employing fractal based models, algorithms and tools to...
In this paper we describe a joint waveform design methodology for distributed imaging RADARs using the concepts of compressive sensing. Compressive sensing is an active area of research that offers the promise of good object reconstruction with a sparse measurement set. The measurement set of the scene is based on a set of dasiaprobes,psila the radar waveforms. The set of measurements must satisfy...
Antenna beam pointing accuracy and stability are key issues for obtaining reliable and high quality remote sensing data in space-borne SAR sensors. A wide set of causes, related to technological aspects and environmental conditions acting at both bus and payload level, contribute to misalign the actual antenna bore sight from the theoretical direction. Even very small error angles on the yaw, pitch...
This work focuses on the classification task performed into a multi-sensor system for the coastal surveillance. The system is composed of two platforms of sensors: a land based platform, equipped with a land based radar, an automatic identification system (AIS) and an infrared camera (IR); an airborne platform, carrying an airborne radar that can operate in a spotlight synthetic aperture radar (SAR)...
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