恒星的连续谱是由于黑体辐射导致的光辐射强度随波长(频率)连续光滑变化的光谱。 每条观测到的光谱数据中都会包含连续谱、 谱线和噪声。 恒星的分类主要是依据光谱的谱线、 连续谱的相对强度以及光谱的其他特征。 恒星连续谱的分布以及谱线的轮廓是由恒星大气内的物理因素决定的, 也可以根据连续谱及谱线对恒星大气的物理参数进行估计。 因而处理光谱的主要问题就是提取连续谱, 并且通过归一化进行谱线的提取。 恒星连续谱提取的算法主要有多项式逼近、 中值滤波、 形态滤波以及小波滤波等, 但是这些方法对于低质量光谱处理的鲁棒性不是很好, 因此有必要研究一种新的算法对低质量光谱的连续谱进行提取。 在仔细分析恒星低质量连续谱的基础上, 提出一种基于蒙特卡罗方法的低质量恒星连续谱拟合方法。 该方法对恒星光谱筛选过程中不在范围内的点利用蒙特卡罗均匀分布进行自动插值, 让每一个波长都对应一个流量点, 然后对这些流量点进行低阶多项式迭代拟合, 从而得到连续谱。 为了验证算法对不同信噪比的低质量光谱连续谱提取的鲁棒性, 利用不同的信噪比在原始光谱中加入不同的高斯白噪声对低质量光谱进行模拟。 结果表明蒙特卡罗算法对不同信噪比的低质量光谱的拟合具有较高的精度与较强的鲁棒性。

The stellar continuum is a sort of spectrum whose light intensity changes continuously and smoothly with wavelength (frequency) due to blackbody radiation. Each observed spectrum contains continuous spectra, spectral lines and noises. The classification of stellar is mainly based on the spectral lines of the spectrum, relative intensity of the continuum and other characteristics of the spectrum. The distribution of the stellar continuum and the contour of the lines are determined by the stellar atmospheric parameter, so the stellar atmospheric parameter can be estimated from the continuum and the spectral lines. Therefore, the main problem of the spectral data processing is to extract the continuum and the lines. The current algorithms for stellar continuous spectral extraction are mainly polynomial approximation, median filtering, morphological filtering and wavelet filtering. However, these methods for the robustness of low-quality spectral processing are not very satisfying. Therefore, it is necessary to study a new algorithm for extracting the continuous spectrum from the low-quality spectra. In this paper, a fitting method for low-quality stellar spectrum based on Monte Carlo is proposed after careful analyses of low-quality stellar continuum. The method is used to automatically interpolate at the point where the spectrum is not in the range of the star spectrum with Monte Carlo, so each wavelength corresponds to a flow point, and then the low-order polynomial iterations are fitted to these flow points for obtaining the continuous spectrum. In order to verify the robustness of the algorithm for low-quality spectral continuum extraction with different SNRs, we use different SNRs to simulate different low-quality spectrum by adding different Gaussian white noise to the original spectrum. The result shows that the proposed algorithm has high accuracy and robustness to the fitting of low-quality spectrum with different SNRs.