[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.