# ERS-1 Overview

In July 1991 the European Space Agency (ESA) launched the first European Remote Sensing Satellite (ERS-1) as a forerunner a new generation of satellites for environmental monitoring (see figure). ERS-1 uses advanced microwave techniques to acquire measurements and images regardless of cloud and sunlight conditions. Such techniques have been used previously only by the short-lived Seasat mission in 1978, and during brief Space Shuttle experiments. In comparison to contemporary satellite systems, ERS-1 is unique in the measurement of certain parameters, including those of sea state, sea surface winds, ocean circulation and sea and ice levels, as well as all-weather imaging of ocean, ice and land. It also measures the sea's surface temperature with greater accuracy than any of the current space systems.

Further, much data will be collected from remote areas such as the polar regions and the southern oceans, for which little comparable information has previously been collected.The nature of the satellite's orbit and its complement of sensors enables a global mission providing world-wide geographical and repetitive coverage, primarily oriented towards ocean and ice monitoring, but with an all-weather high resolution microwave imaging capability over land and coastal zones.

ERS-1 is both an experimental and pre-operational system, since it has to demonstrate that the concept and the technology for the space and ground segments have achieved the required performances. The ERS-1 system was also designed to satisfy some operational requirements for data products needed within a few hours of the observations being made, allowing it to make significant contributions to meteorology, sea state forecasting and monitoring of sea ice distribution - all being important for shipping and offshore activities. The fast delivery of standard products assumes an appropriate ground segment with all the necessary capabilities, not only for data acquisition and processing, but also for data validation, data quality control, data distribution and archiving. It is expected that a gradual transfer of applications from experimental to operational will take place during the lifetime of ERS-1, preparing users for the satellite systems to be launched later in the 1990s.

## ERS-1 Overview

  Satellite Concept
  ERS-1 Orbit
  Payload Summary
  Operational Capabilities
  ERS-1 Specification Table

ESA Earth Observation