Nano-JASMINE: cosmic radiation degradation of CCD performance and centroid detection

摘要

Nano-JASMINE (NJ) is a very small astrometry satellite project led by the National Astronomical Observatoryof Japan. The satellite is ready for launch, and the launch is currently scheduled for late 2013 or early 2014.The satellite is equipped with a fully depleted CCD and is expected to perform astrometry observations for starsbrighter than 9 mag in the zw-band (0.6 µm–1.0 µm). Distances of stars located within 100 pc of the Sun canbe determined by using annual parallax measurements. The targeted accuracy for the position determination ofstars brighter than 7.5 mag is 3 mas, which is equivalent to measuring the positions of stars with an accuracyof less than one five-hundredth of the CCD pixel size. The position measurements of stars are performed bycentroiding the stellar images taken by the CCD that operates in the time and delay integration mode. Thedegradation of charge transfer performance due to cosmic radiation damage in orbit is proved experimentally.A method is then required to compensate for the effects of performance degradation. One of the most effectiveways of achieving this is to simulate observed stellar outputs, including the effect of CCD degradation, and thenformulate our centroiding algorithm and evaluate the accuracies of the measurements. We report here the plannedprocedure to simulate the outputs of the NJ observations. We also developed a CCD performance-measuringsystem and present preliminary results obtained using the system.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.