Geostationary Satellite

Calculate indoor satellite coverage from a geostationary communications satellite.

Model Type

The geometry is shown in Figure 1. The database can be viewed and edited in WallMan. The building's position on earth, around 5400 km north of the equator, was defined when the database was created.


Figure 1. A 3D overview of the indoor database.

Sites and Antennas

A geostationary satellite antenna is positioned at ten degrees longitude and 36,000 km altitude.

Tip: Click Project > Edit Project Parameter and click the Sites tab to view the antenna settings.

In this example, the transmitter power was set to include the high antenna gain.

Computational Method

The computational method is the standard ray tracing model (SRT).
Tip: Click Project > Edit Project Parameter and click the Computation tab to change the model.

To see results on the ground floor of the building, the value for the maximum path loss1 was increased to 300 dB.

Results

Propagation results show at every location the power received from the transmitting antenna by a hypothetical isotropic receiver. Figure 2 shows the results inside and outside the building at a height of 1.5 m.



Figure 2. Indoor and outdoor power coverage of the satellite.

The power level outside the building, without any obstructions, is around -94 dBm. In the shadow of a building, this drops to slightly below -100 dBm. Diffraction at the roof edges enables reception when the line of sight is obstructed. An actual receiver would need an antenna with high gain. Inside the building, on the ground floor, power levels are even lower. There is quite a large variation in the received power, depending on how many walls and floors are penetrated.

1 On the Edit Project Parameter dialog, click the Computation tab, 3D Ray Tracing (SRT - without preprocessed data) > Settings > Selection of Paths and on the Selection of Rays dialog, specify the Max. path loss of rays.