0.5秒测角仪光栅盘最大间隔误差是用三十六面棱体与光栅盘“全组合”测量的。用“全组合”法测得两台样机的误差数据见表1,误差曲线如图1所示。每条误差曲线可以看作是由许多不同频率的谐波综合的结果(组成误差曲线的第n次谐波是一个正弦波或余弦波)。误差曲线分析的目的就是要把误差曲线分离成不同频率的正弦波,并且求出这些正弦波的幅值,从而找到误差的分布规律,拟定消除这些误差的方法。为此我们对误差曲线作富里叶变 0.5 second goniometer The maximum gap error of a grating disk is measured with a “full combination” of thirty-six prism faces and a grating disk. The error data of the two prototypes measured by the “all-combinations” method are shown in Table 1, and the error curve is shown in Figure 1. Each error curve can be viewed as a result of a combination of harmonics at many different frequencies (the nth harmonic that forms the error curve is a sine or cosine wave). The purpose of the error curve analysis is to separate the error curve into sine waves of different frequencies, and to find the amplitude of these sine waves to find the distribution of errors, and to develop ways to eliminate these errors. To this end, we make a Fourier transform of the error curve