EO missions

EO data spans a range of modalities and thematic focuses, presenting distinct trade-offs in spatial detail, temporal revisit, and access regimes. To ground the subsequent discussion of processing baselines and retrieval pipelines, Table 2.1 establishes a concrete taxonomy of the missions that recur most often in large-scale mapping, covering both open-access constellations and commercial platforms, alongside their core specifications and typical applications.

Table 2.1: Earth observation missions that recur in large-scale mapping. Revisit times assume full constellation availability; spatial resolution ranges reflect different acquisition modes or spectral bands. Coverage: 🌐 = global (land & ocean), 🌿 = land surfaces and coastal areas only, 🎯 = tasked/on-demand. ^* The failure of Sentinel-1B induced significant data gaps, see Appendix: Sentinel-1 data gaps. ^† Gaofen-1/6 is openly distributed at Level 1 only: published ARD covers only China and its surrounding areas. ^‡ The Dove constellation provides near-daily coverage of the land surface; sub-daily revisit of a specific site requires tasking a different constellation.

Mission	Modality	Spatial res.	Revisit	Cov.	Active	Typical use cases
Open access
Sentinel-2	Optical	10–60 m	5 days	🌿	2015–	Land cover, agriculture
Landsat	Optical	15–120 m	8–18 days	🌿	1972–	Land cover change
Sentinel-3	Optical	300–1200 m	<2 days	🌐	2016–	Ocean color, SST
MODIS	Optical	250–1000 m	1–2 days	🌐	1999–	Vegetation, fire, albedo
VIIRS	Optical	375–750 m	\(\sim 1\) day	🌐	2011–	Nighttime lights, fire
Sentinel-1	SAR, C-band	5–20 m	6 days	🌐*	2014–	Flood, oil spill mapping
ALOS PALSAR/-2	SAR, L-band	6–100 m	14–46 days	🌐	2006–	Forest mapping
NISAR	SAR, L/S-band	10–20 m	12 days	🌿	2026–	Land, forest, ice change
BIOMASS	SAR, P-band	50–200 m	\(\sim 17\) days	🌿	2025–	Forest biomass
GEDI	LiDAR	25 m footprint	Sparse	±51.6°	2019–	Canopy height, biomass
ICESat-2	LiDAR	11 m footprint	91 days	🌐	2018–	Ice sheet elevation
GRACE / GRACE-FO	Gravimetry	\(\sim 300\) km	30 days	🌐	2002–	Groundwater, ice mass
Gaofen-1/6†	Optical	16 m	2–4 days	🌐	2013–	Agriculture, land cover
Commercial
Planet (Dove)	Optical	3–5 m	Daily‡	🌿	2017–	Change detection
Planet (SkySat)	Optical	0.5 m	🎯	🎯	2016–	Sub-daily site monitoring
Vantor (WorldView)	Optical	0.3–2 m	🎯	🎯	2001–	Change detection, defense
Airbus (Pléiades/SPOT)	Optical	0.3–6 m	🎯	🎯	2002–	Large-area mapping, 3D
ICEYE	SAR, X-band	0.25–3 m	🎯	🎯	2018–	Flood, disaster response
Capella	SAR, X-band	0.5–1.2 m	🎯	🎯	2020–	Infrastructure monitoring
TerraSAR-X / TanDEM-X	SAR, X-band	1–18 m	11 days	🎯	2007–	Elevation models, InSAR