The Contribution of the Earth Observation to the Monitoring of Gas Flaring

Kurzfassung

Global climate changes, which can be observed in the last years, cause a challenge for the society by bringing up new risks of natural hazards and changing natural conditions. One of the important drivers for climate change is the emission of the greenhouse gases to the atmosphere, coming from e.g. industrial sites for conventional energy production, such as oil refineries. During the production of crude oil, natural gas is also being extracted as a side product. Flaring is the cheapest way to dispose of this gas. There are several alternative ways to process it, in order to avoid wasting resources and preventing atmospheric pollution, but nevertheless, they all require investments in infrastructure and are rather unprofitable. Thus, the amount of the flared gas remains high and constitutes a significant problem for the natural environment and climate. Gathering information about gas flaring, e.g. the amount of the gas burned in a specific region of interest, is a complex challenge. Quantification of gas flares in terms of greenhouse gases (GHG) emissions depends on many factors. This comprises not only technical parameter, but also the public availability of needed information. This is especially a hindering aspect in the countries, where such information is not published. Therefore, for the purpose of monitoring, an objective, independent and reliable data source is required. Satellite imagery is very well suited for this task: it can be collected almost permanently, independent of different political and economic institutions, worldwide. Monitoring and mapping of gas flaring have been first introduced to the remote sensing community by Croft in 1978. Recent development of thermal sensor systems, especially with higher spatial resolution, covering wavelengths of the electromagnetic spectrum in the longwave- (LWIR) and in the midwave-infrared (MWIR) opened new possibilities. Especially the NOAA Visible/Infrared Imager Radiometer Suite (VIIRS) and the Sentinel-3 sensor systems can provide necessary information. Nevertheless, until now, there is only one data-base, which is dedicated to collect information on gas flaring, based on VIIRS data, initiated by the World Bank. The German Aerospace Center (DLR) initiated the mission FireBIRD, in order to provide sensor systems that are specially designed for hot-spot recognition and analysis of high-temperature events. The mission consists of two small satellites TET-1 (Technologie Erprobungsträger, eng. OOV: On-Orbit Verification) and BIROS (Berlin InfraRed Optical System), both collect data in the MWIR and LWIR thermal spectrum. Higher data level products include a fire-mask; information on fire area, temperature and calculated fire radiated power (FRP). First investigations on mapping gas flare are presented. The presented study compares the existing data-base on gas flaring, analyses the features of the sensors used and gives an overview on the further needs in this field.