Increasing the Range and Accuracy of Current Bright Object High Precision Astrometry

匹兹堡大学解冻折射器的多通道天体测量光度计(MAP)将进行升级，将震级限制从目前的12级扩展到15级，并将升级以将其精度提高到当前系统的两倍。对于一夜的观测，精确的、相对的天体测量将能够达到几毫角秒。该仪器的独特之处包括：扫描整个恒星场的朗奇光栅以调制恒星流量，使用产生的信号的相位测量恒星之间的角距离，以及用雪崩光电二极管取代旧的光电倍增管。

AST-0138222Gatewood, George D.The Multichannel Astrometric Photometer (MAP) at the Thaw Refractor of the University of Pittsburgh will be upgraded to extend the magnitude limit from its current level of twelve to fifteen and will be upgraded to increase its precision by a factor of two better than the current system. Precise, relative astrometry to a few milliarcseconds for a night's observing will be enabled. Unique aspects of the instrument include: a Ronchi grating scanned across the star field to modulate the stellar flux, angular distances between stars measured using the phase of the resulting signals, and the replacement of the old photomultipliers with avalanche photodiodes.***