Page 25 - SATELLITE AND RADAR COMMUNICATION SYSTEM

1.5 Apply the understanding

of earth coverage area

(foot print)

Satellite altitude and the earth coverage area

 Earth coverage also known as footprint, is the surface area of the earth
that can possibly be covered by a given satellite.

 The effect of satellite altitude on earth coverage provided by the
satellite.

 Refer to figure below, it is evident that the coverage area increases with
the height of the satellite above the surface of the earth.
 It varies from 1.5% of the earths surface area for a low earth satellite

orbit at 200km to about 43% of the earth surface area for a satellite at a
geostationary height of 36000km.

 The figure shows the variation of coverage area as a function of the
satellite altitude.

 The increase in coverage area with an increase in altitude is steeper in
the beginning than it is as the altitude increase beyond 10000km.

 The higher the altitude of the satellite, the smaller is the angular
velocity and the greater will be the displacement of the ground track
towards the west due to the earth rotation.

Figure 1.14: Satellite altitude and earth coverage area

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Introduction to Satellite Communication System