## 7 Conclusions  
In this study, the 30 m resolution GF5-02-AHSI imaging spectrometer and EnMAP payload used, known for their high sensitivity and detection accuracy, have been proven effective in detecting, quantifying, and attributing strong methane plumes to their source facilities. Using the matched filtering method, we identified a total of 16 methane emission point sources in Changzhi, China, and the Permian Basin, with the majority in Changzhi being concentrated in the southeastern region. By employing the IME method to estimate emission rates, our findings indicated that the emission intensities ranged between 1.7 and 75.1 t/h. The high-frequency monitoring capability of the Sentinel-2 satellite, combined with its 20 m spatial resolution, enabled the effective high-frequency monitoring of methane point sources. This approach provided a robust tool for the timely identification and response to methane leaks. The methane emission rates from the Sanyuan Nanyao Coal Mine in Shanxi and the EOG Shale Gas Well in Eddy County varied across different time scales, underscoring the importance of continuous monitoring. Through a comparative analysis of methane emissions in two distinct regions, we observed the differences in the emission characteristics between coal mines and oil and gas facilities. Methane emissions from coal mines may persist for a longer duration but may exhibit lower extreme emission levels compared to oil and gas facilities. We have demonstrated the value of Sentinel-2 satellite observations in detecting and quantifying anomalous methane point sources, leveraging their 20 m pixel resolution and frequent revisit rate. Our methane retrieval utilized reflectance measurements from only two coarse-resolution shortwave infrared (SWIR) bands (band 11, approximately 1560-1660 nm; and band 12, approximately 2090-2290 nm). However, the contrast between these bands and/or with non-plume reference scenes enabled the detection and quantification of sources greater than approximately 3 tons per h under favorable surface reflectance conditions. Our demonstration of Sentinel-2's capability for the high-frequency monitoring of super-emitter methane point sources can be readily extended to other multispectral satellite instruments with similar spectral bands, including Landsat 7 and Landsat 8. In the future, these satellite observation systems could serve as early warning systems to identify high emissions from industrial facilities, enabling prompt corrective actions and significant reductions in total methane emissions at regional and national scales. The integration of multispectral satellite data with targeted instruments like GHGSat for more precise detection, combined with global mapping instruments that can contextualize point source emissions within a regional framework, will be particularly effective. However, attention must be paid to the uncertainties associated with the retrieval of concentration enhancements, which are influenced by limitations in spectral resolution and signal-to-noise ratio. Additionally, in the Changzhi region, the heterogeneity of the surface has led to higher detection limits, posing a significant challenge to the automatic extraction of plumes. Consequently, many point sources with lower emission rates may remain undetected and unquantified, resulting in a conservative estimate of total emissions. Looking ahead, beyond the already operational GF5-02, PRISMA, EnMAP, and EMIT satellites, the upcoming high-resolution imaging spectrometers such as CHIME and Carbon Mapper will further improve the revisit frequency for characterizing global methane point sources. When combined with dense ground-based monitoring networks, these observations are expected to inform Methane Alert and Response Systems (MARSs) [57], aiding in the compilation of robust methane inventories and the evaluation of emission reduction policies. Original draft preparation and formal analysis, X.C. ; review and editing, Y.B. and Q.H. ; software, Z.Y. and Z.L. ; validation, B.L.