Landsat
The longest continuously running family of civilian land-imaging satellites, providing a multi-decade record of land change.
Landsat is a joint US programme whose satellites have observed the land surface since the early 1970s. The archive is the single most important asset for historical land-cover reconstruction: it lets an analyst look at what a site looked like before a project began, which is precisely what a credible baseline demands.
Modern Landsat instruments record eleven bands at thirty-metre resolution with a sixteen-day revisit. Radiometric calibration and consistent processing across decades make the record comparable over time, an unusual and valuable property among Earth-observation archives.
For carbon work, Landsat is typically used for long-run change detection and for establishing historical forest cover, while higher-cadence sensors handle ongoing monitoring. Where Landsat and Sentinel-2 are harmonised, analysts gain both a long past and a dense present.
Frequently asked questions
How far back does Landsat go?
The archive begins in 1972, giving more than five decades of land observations at varying resolution.
Why does historical imagery matter for carbon projects?
Additionality and baselines are counterfactual claims. Historical imagery shows what actually happened on and around a site before intervention.