Reference Stars: Star with known position and/or magnitude, that are used to find the plateconstants and photometric calibration of an image.
参考星：已知位置和/或星等的恒星，用于确定图片的底片常数和光度校准。
2
Using the radio buttons in this section, you can set the software to use linear, quadratic or cubic fits for the plateconstants. Small field CCDs usually require no more than a linear fit.
使用本类里的单选按钮，你可以选择使用底片常数的一次、二次或三次拟合。
3
In this article, the fracture analysis on mode I crack of orthotropic functionally gradient materials is studied, under which the elastic constants changed exponentially along thickness of the plate.