在开放光路条件下,污染气体与大气成分的光谱特征相互混叠,难以直接对污染气体进行识别。提出了一种自适应特征提取算法,预先生成各种大气条件下的光谱特征,利用Lasso算法进行快速特征优选,选择最优目标/背景组合重构背景光谱,提取目标特征。为了验证所提算法的有效性,开展了不同背景下的甲烷遥测实验、不同相对湿度条件下的氨气遥测实验,以及室内近距离乙烯探测实验。将所提算法与Harig算法进行对比,结果表明:所提算法能更好地扣除背景,具有较强的实用性。

Under the open light path condition, the spectral characteristics of polluted gases and atmospheric components are overlapped, making it difficult to directly identify the polluted gases. This study proposes an adaptive feature extraction method, which pre-generates the spectral features under various atmospheric conditions. The rapid feature extraction is performed using the Lasso algorithm for selecting the optimal target-background combination, reconstructing the background spectrum, and extracting the target features. The effectiveness of the proposed algorithm is verified via the methane remote detection under different backgrounds; the ammonia gas detection is also performed under different relative humidity conditions along with the indoor close-range ethylene detection. The proposed method is compared with the Harig's method. The results show that the proposed method can well eliminate background and possesses strong practicability.