This paper introduces a real-time compact optronic SAR processor that has the capability to generate ENVISAT/ASAR image swaths of 100 km x 100 km in 10 seconds exhibiting slant plane sampling distances of 4 meters in azimuth and 1 meter in range. It may be instantaneously reconfigured to process data from any of the 7 ASAR image swath modes. In this respect, numerous SAR image sets may be produced immediately on-demand without bottleneck. A rapid SAR processor that also provides fine ground sampling distances in both azimuth and range directions could provide benefits for such applications as ship detection, landslide and flood monitoring, snow and ice coverage and glacier monitoring.
Synthetic aperture (SA) techniques are currently employed in a variety of imaging modalities, such as radar (SAR) and ladar (SAL). The advantage of fine resolution provided by these systems far outweighs the disadvantage of having large amounts of raw data to process to obtain the final image. Digital processors have been the mainstay for synthetic aperture processing since the 1980's; however, the original method was optical that is, it employed lenses and other optical elements. This paper provides a global review of a compact light weight optronic processor that combines optical and digital techniques for ultra-fast generation of synthetic aperture images. The overall design of the optronic processor is detailed, including the optical design and data control and handling. As well, its real-time capabilities are demonstrated. Example ENVISAT/ASAR images generated optronically are also presented and compared with ENVISAT Level 1 products. As well, the extended capabilities of optronic processing, including wavefront correction and interferometry are discussed. Finally, a tabletop synthetic aperture ladar system is introduced and SAL images generated using the exact optronic processor designed for SAR image generation are presented.
Wavefront sensing is one of the key elements of an Adaptive Optics System. Although Shack-Hartmann WFS are the most commonly used whether for astronomical or biomedical applications, the high-sensitivity and large dynamic-range of the Pyramid-WFS (P-WFS) technology is promising and needs to be further investigated for proper justification in future Extremely Large Telescopes (ELT) applications. At INO, center for applied research in optics and technology transfer in Quebec City, Canada, we have recently set to develop a Pyramid wavefront sensor (P-WFS), an option for which no other research group in Canada had any experience. A first version had been built and tested in 2013 in collaboration with NRC-HIA Victoria. Here we present a second iteration of demonstrator with an extended spectral range, fast modulation capability and low-noise, fast-acquisition EMCCD sensor. The system has been designed with compactness and robustness in mind to allow on-sky testing at Mont Mégantic facility, in parallel with a ShackHartmann sensor so as to compare both options.
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