Remote sensing refers to a set of methods to obtain information about the earth’s surface by measuring the electromagnetic waves emitted or reflected by it. In contrast to other detection methods, which require direct access to the object under investigation or observation, remote sensing is understood to be contact-free exploration. This is made possible by airborne or satellite-borne sensors but also increasingly by drones. Hundreds of optical Earth observation platforms collect spatial data every day making it an almost inexhaustible data source.
Remote sensing is a crucial backbone for the analysis of spatial properties, as its methods allow for a repeatable, standardized and cost-effective environmental assessment. Through open archives or scientific programs, more and more data are being made available free of charge – a growing trend. While the data situation is now greatly improved, there is a lack of standardized procedures for generating data in city-specific products providing planning-relevant information. Cities have unique requirements for remote sensing products, as they are characterized by strong heterogeneity. In the city, very rich and diverse sites with unique niches are found next to intensively used sites that are very far from potential natural vegetation , making the urban environment dynamic and complex.