Glossary:Measurement

Acquiring emissions data directly from the environment at a specific place and time.

Continuous measurement - Methane detection technology installed at a facility to provide repeated emissions measurements at high temporal resolution. Typical continuous measurement technologies may acquire measurements multiple times per second or multiple times per day.

Bottom-up Measurement - A measurement that occurs at a granular scale (e.g., component) that is used to estimate emissions more broadly. Bottom-up measurements are often averaged into emissions factors and combined with activity factors to build a bottom-up inventory.

Top-Down Measurement – Methane measurements taken at spatial scales greater than the equipment scale. Typical top-down measurement scales include site, region and basin. In the production segment, net emissions from a spatially distinct set of equipment, such as a well-pad, a compressor station, or a central processing facility, or from a set of such facilities. Top-down measurements can also include linear assets such as pipelines, when a pipeline is examined.

Site-Level Measurements – Methane measurements of the entirety of emissions from individual sites. This can be based on non-continuous “snapshot“ technology approaches, which take a measurement at a discrete moment in time and does not automatically repeat at a high frequency: continuous monitoring technologies: or a combination of both.