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。

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.

A flat field calibration is automatically applied to all CCD Images that are loaded thereafter.

此后载入的所有CCD图片将针对此平场图片做校正.

A method of field calibration technique for wheelset profile non-contact measurement was proposed by using second-order polynomial warping technique.

本文利用二元二次多项式变形技术，提出了一种轮对外形尺寸非接触测量的现场标定方法。