The second European Remote Sensing Satellite ERS-2, launched on 20
April 1995, operates in a sun-synchronous, near-polar orbit at an
altitude of 785 km and an inclination of 98.5 degrees ,known as the
... reference orbit. The mission consists of an only phase (phase A),
using a 35 day repeat cycle, from 21 April 1995 to the present.
ERS-2 is almost identical to the European Remote Sensing Satellite
ERS-1 launched in 1991. ERS-2 is capable of measuring, on a global
scale, the Earth's atmospheric and surface properties with a high
degree of accuracy. In fact it uses advanced microwave techniques to
collect global measurements and images (much of the data are collected
from remote areas such as the southern oceans and the Antarctic)
independent of time of day and weather conditions. It also undertakes
the measurements of many parameters not covered by existing satellite
systems, including those of sea state, sea surface winds, ocean
circulation and sea and ice levels.
ERS-2 carries on-board a number of instruments consisting of a core
set of active microwave sensors supported by additional, complementary
instruments: the Active Microwave Instrument (AMI), which combines a
Synthetic Aperture Radar (SAR) operating in image or wave mode and a
wind scatterometer, the Radar Altimeter (RA), the Along-Track Scanning
Radiometer and Microwave Sounder (ATSR-2), the Precise Range and
Range-rate Equipment (PRARE), the Global Ozone Monitoring Experiment
(GOME), and Laser Retroreflectors (LRR).
The primary objectives of the ERS-2 mission are the monitoring of the
oceans and sea ice providing essential data for:
- improved representation of oceans/atmosphere interactions
in climatic models
- major advances in the knowledge of ocean circulation and
transfer of energy
- more reliable estimates of the mass balance of the Arctic
and Antarctic ice sheets
- better monitoring of pollution and dynamic coastal
processes
- improved detection and management of land use change.
The capability of ERS-2 to acquire vast global data sets of ocean,
atmosphere, ice and land phenomena contributes to the following types
of study and application:
- Ocean/Ice: ocean circulation, global wind/wave
relationships, sea ice and iceberg monitoring, etc.
- Physical Earth: accurate determination of the ocean
geoid, forestry, glaciology, geology and agriculture
studies, etc.
- Climate: contribution to the World Climate Research
Programme and to the World Ocean Circulation Experiment
- Weather and Sea: short and medium-term weather
forecasting, sea surface State Forecasting wind speed and
direction, location of pelagic fish through the monitoring
of temperature fronts
- Global Ozone: measures ozone, trace gases, and aerosols
in the troposphere and stratosphere 
