High resolution observation by means of tomographic adaptive optics

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Researches carried out in this project were to establish the adaptive optics systems of practical use in order to improve the spatial resolution of large telescopes.(1) The wavefront tilt correcting system, the so-called image stabilizer, optimized for the Coude infrared spectrograph of Okayama 188cm telescope was assembled and calibrated for actual usage. In order to enhance the efficieny of this system, an adptive control system of the servo loop was designed, tested, and implemented.(2) A joint experiment with the CFHT group to evaluate the internal dome seeing at the existing telescope enclosure is outlined and a special original instrument, named a dome-seeing monitor, was fabricated and calibrated.(3) A deformable mirror, 50mm in diameter, 0.5mm in thickness, mounted on 37 piezo actuators was fabricated and calibrated.(4) A new type parallel-read CCD with skipper architecture to reduce the read noise and ensure fast frame rate was designed and manufactured in collaboration with the JPL.An electronic system to evaluate the performance of this system is under construction.(5) Control algorithm to calculate the drive signal from wavefront error was etablished.(6) Simulation of curvature sensing to evaluate the vertical structure of the turbulent atmosphere was made.(7) Practical problems of evaluating the 3D structure of turbulent air using tomographic methods were assecced and possible ways to solve these difficulties were studied.These achievements are in line with the original research goals of the present project and opened a practical way to establish an adaptive optives system useful for astronomy.