Institute of Methodologies for Environmental Analysis, National Research Council, 85050 Tito Scalo, Italy.
Satellite Application Centre (SAC), Space Technologies and Applications Centre (STAC), 85100 Potenza, Italy.
Sensors (Basel). 2023 Jun 20;23(12):5734. doi: 10.3390/s23125734.
The synergic use of satellite data at moderate spatial resolution (i.e., 20-30 m) from the new Collection 2 (C2) Landsat-8/9 (L8/9) Operational Land Imager (OLI) and Sentinel-2 (S2) Multispectral Instrument (MSI) provides a new perspective in the remote sensing applications for gas flaring (GF) identification and monitoring, thanks to a significant improvement in the revisiting time (up to ~3 days). In this study, the daytime approach for gas flaring investigation (DAFI), recently developed for identifying, mapping and monitoring GF sites on a global scale using the L8 infrared radiances, has been ported on a virtual constellation (VC) (formed by C2 L8/9 + S2) to assess its capability in understanding the GF characteristics in the space-time domain. The findings achieved for the regions of Iraq and Iran, ranked at the second and third level among the top 10 gas flaring countries in 2022, demonstrate the reliability of the developed system, with improved levels of accuracy and sensitivity (+52%). As an outcome of this study, a more realistic picture of GF sites and their behavior is achieved. A new step aimed at quantifying the GFs radiative power (RP) has been added in the original DAFI configuration. The preliminary analysis of the daily OLI- and MSI-based RP, provided for all the sites by means of a modified RP formulation, revealed their good matching. An agreement of 90% and 70% between the annual RPs computed in Iraq and Iran and both their gas-flared volumes and carbon dioxide emissions were also recorded. Being that gas flaring is one of the main sources of greenhouse gases (GHG) worldwide, the RP products may concur to infer globally the GHGs GF emissions at finer spatial scales. For the presented achievements, DAFI can be seen as a powerful satellite tool able to automatically assess the gas flaring dimension on a global scale.
利用新的陆地卫星 8/9 操作陆地成像仪（OLI）和哨兵 2 多光谱仪器（MSI）中等空间分辨率（即 20-30 米）的卫星数据协同作用，通过将重访时间（高达约 3 天）显著提高，为天然气燃烧（GF）识别和监测的遥感应用提供了新的视角。在本研究中，最近开发的用于在全球范围内利用 L8 红外辐射识别、绘制和监测 GF 地点的日间天然气燃烧调查方法（DAFI）已被移植到虚拟星座（VC）上（由 C2 L8/9+S2 组成），以评估其在理解时空域中 GF 特征的能力。在 2022 年排名第二和第三的十大天然气燃烧国——伊拉克和伊朗地区的研究结果，证明了所开发系统的可靠性，提高了准确性和敏感性（+52%）。作为这项研究的结果，实现了对 GF 地点及其行为的更真实的描述。在原始 DAFI 配置中添加了一个新的步骤，旨在量化 GF 的辐射功率（RP）。通过修正的 RP 公式，对所有地点提供的基于每日 OLI 和 MSI 的 RP 进行了初步分析，结果表明它们很好地匹配。在伊拉克和伊朗计算的年度 RP 与其天然气燃烧量和二氧化碳排放量之间也记录到了 90%和 70%的一致性。由于天然气燃烧是全球温室气体（GHG）的主要来源之一，RP 产品可以共同推断全球范围内更精细空间尺度的 GHG 天然气燃烧排放。对于所取得的成就，可以将 DAFI 视为一种强大的卫星工具，能够自动评估全球范围内的天然气燃烧规模。
