高光谱遥感识别地下储存天然气微泄漏点

如何及时准确探测天然气地下储存库或管道出现的微泄漏点目前尚是一个难题。通过野外可控系统模拟天然气微泄漏实验，研究天然气微泄漏对地表植被的影响及遥感特征变化，从而间接探测天然气微泄漏点。实验以草地与大豆为研究对象，测量了胁迫区与对照区植被的冠层光谱，进行奇异值剔除和平滑处理，对一阶微分处理后的植被冠层光谱再进行连续小波变换分析，发现对照组与胁迫组植被冠层光谱小波能量系数在685和715 nm处差异较大，且规律稳定，用其构建归一化指数(DW₆₈₅-DW₇₁₅)/(DW₆₈₅+DW₇₁₅)(DW)，并与PRI，NPCI，NDVI，D₇₂₅/D₇₀₂指数进行对比分析，经J-M距离检验，结果表明归一化指数DW在识别天然气微泄漏胁迫下的草地和大豆具有较好的识别效果，且比PRI，NPCI，NDVI，D₇₂₅/D₇₀₂指数具有更好的普适性与稳健性。该结果表明，通过高光谱技术间接检测天然气微泄漏点具有可行性，为以后的工程应用提供技术支持和理论基础。

Detection of Microleakage Point of Underground Natural Gas Using Hyperspectral Remote Sensing

It is a challenge to timely detecte microleakage of natural gas which is stored in underground repository or pipeline. The response and other remote sensing characteristics of stressed vegetation were used to indirectly detect the microleakage point of natural gas via controlled experiments in the field. In detail, the canopy reflectance of stressed area and control area of soybean and grassland were measured respectively. Singular values were removed and spectrum was smoothed, then spectra of the canopy reflectance was analyzed using the method of continuous wavelet based on first-derivative, which showed that wavelet energy coefficients of stressed and control canopy reflectance at 685 and 715 nm were good features to separate the stressed and control groups. (DW₆₈₅-DW₇₁₅)/(DW₆₈₅+DW₇₁₅) (DW) was designed in this paper using 685 and 715 nm and compared to PRI, NPCI, NDVI, and D₇₂₅/D₇₀₂, which showed that better performance, universality and robustness were possessed by DW in identifying the stressed grassland and soybean. The results showed that it is feasible to indirectly detect natural gas microleakage points through hyperspectral technology, which can provide technical support and theoretical basis for future engineering applications.