Natural gas leakage occur frequently due to aging pipes and other factors, but are challenging to detect. In this study, a new, robust method for non-destructive natural gas micro-leakage detection was proposed. It combines a crop growth model with a convolutional neural network (CNN) approach to quantitatively detect underground natural gas leakage using unmanned aerial vehicle (UAV) hyperspectral imagery. The environmental stress on wheat was used as an indicator to reflect the intensity of natural gas leakage. First, a crop growth model (Simple Algorithm For Yield, SAFY) was used to simulate the growth of wheat, and the environmental stress factor in the model was used to construct the natural gas stress index (Kgs). Subsequently, CNN models were used to estimate the Kgs value with a hyperspectral image as the input. Finally, the CNN estimated Kgs was used to detect the natural gas leakage in the study area. Results showed that the SAFY model Kgs value could effectively identify natural gas leakage, with statistically significant differences (p-value < 0.05) among three leakage levels. Furthermore, compared to a single spectral index, Kgs had superior robustness throughout the wheat growth period. The CNN-1D model with InceptionV2 architecture exhibited the best accuracy in estimating Kgs, with a robust nRMSE of 6.9%. Overall, the combined CNN and SAFY models could accurately detect natural gas leakage, and this approach is more robust than traditional spectral index based methods. This study provides a new method for non-destructive detecting of natural gas micro-leakage. Index Terms-Hyperspectral image; SAFY model; natural gas micro-leakage; CNN.
I. INTRODUCTIONATURAL gas is a safe, environmentally friendly, and high-quality energy source, and occupies an important market position. Pipelines are common methods of transport and underground storage is widespread [1]. However, both are susceptible to damage from natural or human factors, and the resulting gas leakage can be hazardous and result in economic losses [2]. Therefore, it is important to detect natural gas leakage in a timely and accurate manner.