We report the development of MuSCAT3, a four channel simultaneous imager installed on the 2m Faulkes Telescope North at Haleakala Observatory on Maui, Hawai’i. MuSCAT3 has a capability of 4-color simultaneous imaging in g (400–550 nm), r (550–700 nm), i (700–820 nm), and zs (820–920 nm) bands with four independent 2048×2048 pixel CCDs, each having a field of view of 9.1×9.1 arcmin2 with a pixel scale of 0.27 arcsec per pixel. The development of MuSCAT3 started from September 2019, and MuSCAT3 achieved its first light on September 28th, 2020. The Las Cumbres Observatory started science operations of MuSCAT3 since November 4th, 2020, although a part of its capabilities are still limited.
For efficient visual inspection of moving targets, such as walls, surfaces of structures, roads, assembly lines, and so on in real-time, inspection systems must have a simple yet robust design capable of operating at high speed. However, high-speed motion degrades image quality due to motion blur and defocusing which are conventionally compensated separately. In this research, we propose a focus adjustable motion-blur compensation method using one deformable mirror capable of back-and-forth movement and curvature bending. The deformable mirror, installed between a target and a 2D camera, simultaneously tracks the moving target and adjusts the focus to achieve high-quality images in real-time without image processing. Through the experiment using a camera having VGA resolution and frame rate of 30Hz, a deformable mirror with a pupil size of 10mm and 43 actuators for deformation and tip/tilt, and a moving target, the results showed that our system improved motion blur and focusing at the same time with only one device. As future work, entire system can be packaged into inspection system.
We report the development of a four-color simultaneous camera for the 1.52-m Telescopio Carlos Sánchez in the Teide Observatory, Canaries, Spain. The instrument, named MuSCAT2, has a capability of four-color simultaneous imaging in g (400 to 550 nm), r (550 to 700 nm), i (700 to 820 nm), and zs (820 to 920 nm) bands. MuSCAT2 equips four 1024 × 1024 pixel CCDs, having a field of view of 7.4 × 7.4 arc min2 with a pixel scale of 0.44 arc sec per pixel. The principal purpose of MuSCAT2 is to perform high-precision multicolor exoplanet transit photometry. We demonstrate photometric precisions of 0.057%, 0.050%, 0.060%, and 0.076% as root-mean-square residuals of 60 s binning in g, r, i, and zs bands, respectively, for a G0 V star WASP-12 (V = 11.57 ± 0.16). MuSCAT2 has started science operations since January 2018, with over 250 telescope nights per year. MuSCAT2 is expected to become a reference tool for exoplanet transit observations and substantially contributes to the follow-up of the Transiting Exoplanet Survey Satellite and Planetary Transits and Oscillations of stars space missions.
In this paper, motion-blur compensation method for micro fabricated objects using a galvanometer mirror with back-and-forth rotation is proposed. Motion-blur compensation is expected to extend exposure time without motion blur because longer exposure time can decrease the intensity of illumination to avoid shape expansion of a target object by heat of illumination. Dealing with this demand, a galvanometer mirror is installed between the target and a 2D high-speed camera, and controls the optical axis of the camera to follow the moving target. Each continuous images are taken during the motion of the stage, and finally taken images are integrated into one image by patching for detecting fabrication error using image processing. The experimental system that consists of a high-speed camera, a galvanometer mirror and a high-precision stage is developed and a 20mm=/s moving drilled silicon nitride sheet having holes of about 40 μm in diameter are lattice-shaped at a pitch of 60 μm is captured without motion blur by using this system. Comparing captured images with still images in diameter, roundness and curvature of the each holes, the effectiveness of this system is validated.