Satellietfotos

Satellietfotos, or satellite photos, are images of Earth captured by imaging sensors aboard orbiting spacecraft. They are used for mapping, monitoring, and analysis across sectors such as forestry, agriculture, urban planning, weather, and disaster response.

Imaging systems include passive optical sensors that collect reflected sunlight and infrared bands, and active radar sensors (synthetic aperture radar, SAR) that emit microwaves and record their return. Spatial resolution ranges from sub-meter to tens of meters, and swath width from hundreds of kilometers. Common examples include Landsat, Sentinel, and various commercial satellites such as WorldView and PlanetScope.

Historically, first usable satellite imagery emerged in the 1960s from reconnaissance programs like Corona. Civilian land-imaging began with Landsat in 1972, and Europe’s Copernicus Sentinel program began delivering data in the 2010s.

Data access and licensing vary: Landsat and Copernicus provide open data, enabling broad scientific and public use. Commercial providers offer higher-resolution imagery under license to governments, companies, and researchers.

Applications include land cover mapping, crop monitoring, forestry, water resource management, urban planning, climate research, and disaster response. Imagery is processed into orthoimagery and derived products such as NDVI for vegetation health, and is distributed in formats like GeoTIFF and JP2 after atmospheric and geometric corrections.

Challenges include cloud cover, atmospheric interference, data volume, and the need for specialized software and standards to integrate imagery with other geographic data. Privacy and surveillance concerns are frequently discussed as high-resolution imagery becomes more widely available.