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ABSTRACT We propose a data reduction approach called global optimization-based reference star differential imaging (G-RDI), which can be used for exoplanet imaging survey, where large numbers of target stars from the same young stellar association are imaged and where no field rotation is needed. One of the unique features of our G-RDI is that we select reference stars from other scientific target stars in the same stellar association to optimize for high-contrast imaging with a target star, which maximizes the observational efficiency and also delivers good performance to remove the speckle noise so that high contrast is achievable even at a small inner working angle (IWA) to the host star of being imaged. We proposed the G-RDI that is optimized for high-contrast exoplanet imaging at a small IWA and to provide a contrast that is significantly better than the current reference star differential imaging (RDI) method. In addition, we also propose the use of multiple reference stars and found that our G-RDI can further deliver better performance in that case. The result was compared with other exoplanet data reduction techniques, including the traditional RDI, and it indicated that our G-RDI with two reference stars can significantly improve the contrast performance at a small IWA with a high observational efficiency – two critical features that current data reduction techniques cannot offer. This approach could be used with both equatorial and alt-azimuth mount telescopes, and provides a new option for future exoplanet imaging surveys with high observational efficiency at a small IWA. 

Abstract We have developed a portable solar adaptive optics (PSAO) for diffraction-limited imaging based on today’s multi-core personal computer. Our PSAO software is written in LabVIEW code, which features block-diagram function based programming and can dramatically speed up the software development. The PSAO can achieve a ~1000 Hz open-loop correction speed with a Shack–Hartmann Wave-front Sensor (SH-WFS) in 11 × 11 sub-aperture configuration. The image shift measurements for solar wave-front sensing are the most time-consuming computations in a solar adaptive optics (AO) system. Since our current LabVIEW program does not fully support multi-core techniques for the image shift measurements, it cannot fully take advantage of the multi-core computer’s power for parallel computation. In order to accelerate the AO system’s running speed, a dedicated message passing interface/open multi-processing parallel programming technique is developed for our LabVIEW-based AO program, which fully supports multi-core parallel computation in LabVIEW programming. Our experiments demonstrate that the hybrid parallel technique can significantly improve the running speed of the solar AO system, and this work paves the way for the applications of a low-cost and duplicable PSAO system for large solar telescopes.