一种快速求红移和证认谱线的新方法--伪三角法

对于河外天体，谱线证认和红移确定是光谱分析的第一步。本文在仔细分析天体光谱特点的基础上，提出了一种全新的求红移和证认谱线的新方法--伪三角法。该方法利用最强的三根谱线的波长信息构造“三角形”，通过将最大角的“余弦”与已知模板的“余弦”表相匹配，反推得到相应的标准谱线波长，并进而得到红移值。通过这个红移值，可以得到所有的谱线的标准位置，这就相当于谱线证认。结果表明：这种方法在大大减少运算量的同时，保持了较高的正确识别率和极低的误识率。这对海量光谱数据的处理具有重要的意义。同时，该方法立意新颖，简单明了，容易实现。缺点是对于谱线少于3根的光谱以及噪声很大的光谱不能有效地处理。

A Pseudo-triangle Technique for Redshift Identification of Celestial Spectra

In this paper,we present a novel technique for redshift identification.Redshift is a key parameter of celestial spectra.In the literature,there are few reports on redshift identification due to either no many people working on the problem or perhaps industrial confidentiality.Our technique is a pseudo triangle technique.It consists of the following three major steps:in the first step,the three wavelengths corresponding to the three highest intensity values of an unknown spectrum are selected to construct a pseudo triangle,and the largest angle of this triangle is calculated which is independent of redshift value.In the second step,the obtained angle is used as an index to retrieve the corresponding three model wavelengths via a pre calculated look up table,which is composed of all the combinations of all the feature wavelengths of the model spectrum.And finally,based on the three corresponding wavelengths,the corresponding redshift value is derived. The main characteristic of our technique is its simplicity and efficiency,which is demonstrated by experiments on simulated data as well as on real celestial spectra.It is shown that the correct identification rate can reach as high as 86%.Taking into account the high noisy nature of celestial spectra,such a result is considered a good one.