For this study, multiple working sessions were conducted with operators to capture facility configurations, called prototypical sites (PSs), that serve as representative models for their production sites. Development of the PSs and classification methods are described in SI Section S-6. Given a PS to represent a site, 300 the scale of the site (Site Information) can be developed from regulatory reporting or similar inventory data. Using reported data scales individual sites to the appropriate equipment complexity and throughput In this study the General Aviation Operations (GAO) aircraft had a high detection limit (10s to 100s kg/h ), an observation time of a few seconds and spatial resolution no better than the scale of a major equipment (e.g., tanks, compressors, flares) group. Aerial detections were first classified (approximately) as 325 maintenance versus failure conditions , then all failure-induced emissions were aggregated into a single category to simulate in MAES. This is equivalent to aggregating all failures to the facility level. To compare aerial and simulated data, MAES results were similarly binned in time (seconds) and space (facility). The frequency of detected emitters was calculated from the frequency observed by the aerial method, while the estimated durations were varied from 3 to 14 days. Results of the simulation are not sensitive to the failure 330 duration for the purposes used here, see SI Section S-7.