EO services and applications are organized according to thematic areas. EO is used for a wide set of services. There are many applications of EO that show how a service produces information for a particular client. EO service and applications are best described by the purpose they serve or by the need of the user. The main user needs to EO are to monitor, to map, to forecast, to assess, to detect, and to analyse.
To monitor means to watch and check a situation carefully for a period of time in order to discover something about it, i.e. keeping track of how the natural and manmade environment change (their status) over time. Typical alternative verbs are track, observe, record, follow, understand, or surveil.
To map means to represent an area of land in the form of a map, i.e. to feature and locate the way it is arranged or organized. Synonymous verbs are locate, identify, classify, trace, or record.
To forecast means to provide statements covering a range of different outcomes, to say what you expect to happen in the future; i.e. to predict future events based on specified assumptions (about information extracted from EO change and time series data), where different sets of assumptions describe scenarios. Equivalent terms are predict, plan, model, estimate, or project.
To assess means to judge or decide the amount, value, quality or importance of something, i.e. to evaluate and measure the status of and changes in natural and manmade built environments. Alternative verbs are evaluate, measure, understand, review, or quantify.
To detect allows to notice something that is partly hidden or not clear, or to discover something, especially using a special method, i.e. to identify and locate the changes in the Earth’s environment. Similar terms are locate, warn, identify, highlight, or spot.
To analyse means to study or examine something in detail, in order to discover more about it, i.e. to detail the elements of a whole and critically examine and relate these component parts separately and/or in relation to the whole. Sometimes, the terms to process, to parse, or to detail are used in exchange for to analyse.