Table 1.

Overview of earth observation (EO) data

	High-resolution satellite (HR)	Very high-resolution satellite (VHR)	Aerial (airplane)	UAV (“Drone”)
Grid cell size (spatial resolution)	~ 5 m–30 m	~ 0.3–3 m	~ 0.1 m–0.4 m	< 0.1 m
Typical coverage area	National	Sub-national (e.g., admin 1, metropolitan area)	City or district	Neighborhood
Cost per sq km	Free	Low	High	High
Constraints	Difficult in cloud-covered areas (e.g., tropical areas)	Difficult in cloud-covered areas (e.g., tropical areas)	Availability of an aerial survey company, flight authorization, meteorological conditions	Availability of a pilot and a drone, flight authorization, wind conditions