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Satellite Data

Understanding Satellite Emissions Monitoring

Published on December 10, 2025

How public satellites from NASA, ESA, and JAXA are used to measure greenhouse-gas and air-quality emissions from orbit, and what that data is good for.

Overview

Satellite emissions monitoring uses spectrometers in low Earth orbit to measure trace-gas concentrations in the atmospheric column above an asset. Six active greenhouse-gas missions across NASA, ESA, and JAXA, paired with broader Earth-observation constellations, supply the raw measurements Floodlight uses to produce facility-level emission estimates without relying on self-reported activity data.

How It Works

Each mission carries a spectrometer tuned to the absorption lines of specific gases: TROPOMI on Sentinel-5P for NO2, CO, SO2, and CH4; OCO-2 and OCO-3 for CO2; the GOSAT lineage (GOSAT, GOSAT-2, GOSAT-GW) for CO2 and CH4. Floodlight ingests the public retrievals, traces each reading backward through 3D wind fields to its likely source, and applies a Bayesian inversion to convert column concentrations into facility-level emission rates. Every figure ships with a published margin of error.

Key Benefits

  • Independent of self-reported activity data
  • Facility-level attribution with published uncertainty on every estimate
  • Global coverage across NASA, ESA, and JAXA missions
  • Refresh on the satellite overpass cadence, typically days to weeks
  • Audit-ready provenance from raw radiance to delivered figure

Applications

Banks use the data for climate-VaR underwriting and regulatory stress testing. Corporates use it for Scope 1 disclosure that does not depend on self-reported inventories. Cities map emissions block-by-block to target the streets, sectors, and infrastructure that drive their citywide budget. Regulators use it as an independent check on bottom-up inventories.

Floodlight - Climate Risk Intelligence