Reporting & assurance → Measurement reconciliation compares independent site-level (top-down) methane measurements, for example from an aerial, satellite, drone or continuous-monitor survey, with the source-level (bottom-up) inventory of the same asset, and keeps a log of what your organisation decided.
Framework only
EmitLedger provides the framework and the arithmetic, not the rules. Reconciliation thresholds (for example which difference needs an investigation, or how many campaigns a year are expected) and the OGMP 2.0 and other pack rules about reconciliation are subject-matter-expert (SME) content, set by your organisation’s methodology owner or added to a pack by an SME. Until then the page shows the comparison and never marks a result as passing or failing.
Add a measurement
Data providers and administrators can add measurements.
- Click Add measurement and choose the asset.
- Enter the Campaign (optional), the dates Measured from and Measured to, the Technology (a free label, e.g. aerial LiDAR) and the Provider.
- Enter the Measured CH₄ value and its Unit: a CH₄ mass rate (g/s, kg/s, kg/h, t/h, kg/d, t/d) or a mass for the whole window (kg, t).
- If the provider reports it, enter the Uncertainty (95 % confidence), as ± % of the value or in the value’s unit, and the Detection threshold.
- Add Coverage notes and attach the provider’s report under Evidence.
The value and unit are stored exactly as entered. A measurement used by a reconciliation cannot be deleted.
Compare with the inventory
Reviewers, methodology owners and client admins can compare.
- Click Compare on a measurement.
- Choose the window (From month, To month) and the Annualisation basis: Rate × calendar hours of the window, Rate × operating hours (enter the hours) or Measured mass as is.
The basis is your methodological choice: scaling a measured rate to a month or a year assumes the rate is representative of the whole window.
The bottom-up side is the current Scope 1 CH₄ results of the asset for those months (operational control), with their combined uncertainty (Data quality). The Reconciliations table and the detail show:
- Bottom-up (t CH₄) and Top-down (t CH₄), each with its 95 % range;
- the Difference (top-down − bottom-up), in t and in % of the inventory, and the Top-down / bottom-up ratio;
- whether the two 95 % ranges overlap, and whether the difference lies within the Combined uncertainty of the difference;
- warnings such as Below detection threshold, Measurement dates outside the window, or Some results are CO₂e only (the bottom-up CH₄ may then be understated).
When an uncertainty is not known, the figures that depend on it show a dash rather than zero. The numbers are a snapshot: after the inventory or the measurement changes, the row says Measurement changed: recompute, and Recompute refreshes it.
Record a decision
Open a reconciliation and use Record decision. Choose the Outcome (Accepted, Inventory adjusted, Measurement rejected or Under investigation) and write the Rationale; you can attach evidence to each decision. The latest decision sets the status. The decision log cannot be edited or deleted.
A reconciliation never changes inventory results. To adjust the inventory, request a restatement, make the correction through it, and link it to an Inventory adjusted decision; that outcome requires the link.
On the methane dashboard
The Methane dashboard shows a Site-level measurement reconciliation panel with the number of measurements and reconciliations in the period, how many have ranges that do not overlap, and a link to this page.