Page 100 - Digital Analysis of Remotely Sensed Imagery

Overview of Remotely Sensed Data 71

Approximate
Nominal
Resolution (m)
Swath Incident
Beam Mode Polarization Width (km) Range Azimuth Angle (°)
Ultra-fine Selective 20 3 3 30–40
Multi-look fine single 50 8 8 30–50
Fine 25 12 8 20–41
Quad
Standard 25 25 8 20–41
Fine 50 8 8 30–50
Standard 100 25 26 20–49
Wide 150 30 26 20–45
Selectives
ScanSAR
narrow 300 50 50 20–46
ScanSAR wide 500 100 100 20–49
Extended high 75 18 26 49–60
Single
Extended low 170 40 26 10–23

Source: MDA, 2008.
TABLE 2.30 Typical Spatial Resolutions of Radarsat-2 Imagery in Different Beam
Modes and Polarizations

Similar to all other radar data, Radarsat images are best applied
to areas that cannot be adequately imaged with optical sensors. In
comparison with optical sensor data, Radarsat data offer useful
values in identifying mesoscale ocean features, such as icebergs and
sea ice, oil spills, and geological structures. It is also possible to detect
underwater topography from Radarsat data through local changes in
the surface roughness pattern. Other applications of Radarsat data
include mapping of topographic relief and production of DEMs.

2.6.4 EnviSat Data
The Environmental Satellite (EnviSat) is an ambitious and innovative
Earth observation satellite that was launched into a sun-synchronous
polar orbit on March 1, 2002, by the European Space Agency. It has a
return period of 35 days, though most of the Earth can be imaged within
1 to 3 days. EnviSat completes one revolution around the Earth in
100 minutes. Its orbit of about 800 km high has an inclination of 98.54°.
This satellite was designed to facilitate the monitoring and study of the
Earth’s environment and climate changes, and to manage and monitor
the Earth’s resources, the atmosphere, ocean, land, and ice.
EnviSat maintains all the capabilities of its predecessors, the
ERS-1 (mission ended on March 10, 2000) and ERS-2 satellites, in
addition to many new capabilities. Its comprehensive payload is
made up of 10 sophisticated optical and radar sensors, such as
Medium Resolution Imaging Spectrometer (MERIS), and Advanced