# Single-blind validation of space-based point-source detection and quantification of onshore methane emissions

## TL;DR

This study tests satellite systems' ability to detect and measure methane emissions from onshore sources, finding they perform well compared to airborne methods.

## Contribution

First single-blind satellite methane detection test with multiple teams and satellites, providing performance benchmarks.

## Key findings

- 71% of methane emissions were correctly identified by satellite teams.
- 75% of quantified emissions were within ±50% of actual values.
- GHGSat's system quantified low emissions (0.2 t/h) with 13% accuracy.

## Abstract

Satellites are increasingly seen as a tool for identifying large greenhouse gas point sources for mitigation, but independent verification of satellite performance is needed for acceptance and use by policy makers and stakeholders. We conduct to our knowledge the first single-blind controlled methane release testing of satellite-based methane emissions detection and quantification, with five independent teams analyzing data from one to five satellites each for this desert-based test. Teams correctly identified 71% of all emissions, ranging from 0.20 [0.19, 0.21] metric tons per hour (t/h) to 7.2 [6.8, 7.6] t/h. Three-quarters (75%) of quantified estimates fell within ± 50% of the metered value, comparable to airplane-based remote sensing technologies. The relatively wide-area Sentinel-2 and Landsat 8 satellites detected emissions as low as 1.4 [1.3, 1.5, 95% confidence interval] t/h, while GHGSat’s targeted system quantified a 0.20 [0.19, 0.21] t/h emission to within 13%. While the fraction of global methane emissions detectable by satellite remains unknown, we estimate that satellite networks could see 19–89% of total oil and natural gas system emissions detected in a recent survey of a high-emitting region.