For astrometric purposes, dark frame and flat field calibration is recommended.

出于天文测量要求，暗场图和平场图校准是被推荐的。

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Astrometric Limit: The maximum residual in the place of a reference star, specified in arc seconds.

天文测量误差极限：参考星位置对应的最大误差，用角秒表示。

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If you save the images after astrometric data reduction has been performed, the software will add WCS keywords to the FITS header.

如果你的图片经过天文测量数据分类转换后储存，本软件将在FITS文件头部分添加wcs关键词。

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It will have two telescopes mounted at opposite ends of a ten-metre boom, and will be able to measure astrometric wobbles as small as a millionth of an arcsecond.

ECONOMIST: A roadmap for planet-hunting

By using an entirely different planet-hunting approach, it should be able to plug this gap, and provide a means of calibrating the census figures resulting from the radial-velocity and astrometric searches.

ECONOMIST: A roadmap for planet-hunting

Astrometric and radial-velocity searches for planets are neatly complementary.

ECONOMIST: A roadmap for planet-hunting