Optical feeder-links play crucial role in closing the global broadband coverage gaps. Point-to-point GEO satellite links provide advantage of uninterrupted availability limited only by ground conditions at the cost of higher SWaP to be able to close the link budget. By increasing field-of-view of the on-board optical terminals to approximately 1◦ × 4◦ , coverage over large enough area for exploitation of site diversity with more than ten optical ground stations and thus network availability above 99.9% can be achieved. We discuss design challenges and constraints together with trade-off evaluation towards the final design. We present optical and mechanical design of a payload prototype, including telescope with 250mm aperture, capable of tracking multiple optical ground stations over entire Mediterranean region. The tracking system concepts are presented to show potential compensation of the orbital effects that arise due to platform vibrations and orbital inclination. The preliminary results of the breadboard´s verification and acceptance process are presented. Insight into manufacturing, assembly, integration and testing stage of the individual prototype sub-assemblies will be given. Finally, system trade-off between various concepts as well as between the traditional use of multiple optical payloads and the presented baseline will be shown and discussed. The goal is to demonstrate the practical application potential of the multiple optical receive systems for future optical GEO feeder-links.
Micro-satellites equipped with multispectral payloads are now under development to acquire information on the radiation reflected and emitted from the earth in the vis-NIR-TIR bands. In this framework, we are studying different approaches based on the compressive sampling technique supported by innovative multispectral detectors, where the image sampling is performed on the telescope focal plane with a Digital Micromirror Device (DMD). We will describe in the paper the possibilities and the constraints given by the use of the DMD in the focal plane. The optical design of the telescope, relay system and detector in two different application cases will be provided.
Information is presented as to the design of a versatile pattern light projection device that has been essential in
the development of the Artemis Broad Spectrum Vision System for imaging of spatial tissue oxygen-saturation
measurement as well as of near infrared fluorescent-labeled tumors to facilitate their surgical removal. The
combined technology for molecular imaging (Artemis Camera) and image-guided projection of light (Artemis
DMD-Projection System) is of significant benefit for various clinical applications. In case of tissue oxygen
measurements, the application of illumination patterns of specific near-infrared light and concomitant read out of
reflected light from non-illuminated areas theoretically will reveal information from deeper structures. As
regards tumor surgery, photodynamic therapy for elimination of tumor tissue is the most exciting and even more
demanding, in that the areas to be illuminated perfectly have to match the areas where cancerous tissue is
detected. Several performance criteria had to be met for the projection system: mixing wavelengths from
different light sources via a 3-channel prism; apochromatic from 430 to 1,000 nm; the projector's zoom-function
to follow the Artemis camera zoom settings; the angle of projection to adapt to the full working distance range;
and the integration of O2view´s custom camera controls with the DLP-chip.
The realization of an integrated, flexible, and robust CIM vision system, suitable for performing quality-assurance surface inspections is discussed. The optimized combination of advanced optics, optomechanics, and flexible image sensor realizes a high 'virtual resolution' without penalizing the pixel transfer rate. High computation rates are obtained by complementing the fractal inspection algorithm with a dynamic hologram, a modular data flow processor, and the system computer. The integrated vision system is validated for the surface quality inspection of concrete tiles in an industrial environment. The overall system performance is discussed in detail and the potential of the system for other application fields will be addressed.
A novel active vision system for CIM production and inspection applications has been developed in the framework of ESPRIT II project No. 5194 (CIVIS). The system consists of a unique, integrated combination of novel components: camera head, data acquisition electronics, a custom digital image processor, control hardware and a commercial framestore, all under the direction of control and processing software on a PC-486 platform. The camera head incorporates a fast zoom lens in combination with a pan/tilt mirror system, allowing region-of-interest acquisition. The special 256 X 256 MOS image sensor offers programmable resolution and random pixel access. The unique combination of optics, optomechanics and versatile image sensor has a high `virtual resolution,' corresponding to more than 1k X 1k pixels but without the overhead of a high pixel transfer rate. The fast computation of the algorithm employed for the fractal inspection of surfaces is realized with an unusual combination of an electrically switchable hologram (for performing all linear operations at the speed of light in the optical domain), a module-based digital processor and the host computer. In this way, active vision for the inspection of concrete tile surfaces has been implemented by acquiring only relevant image data and elegantly processing them in the most appropriate domain.
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