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Latitude and longitude explanation

Link budget calculator

IET satellite communications summer school

How satellite TV works

VSAT network design

Astra beam coverage

O3b beams

Antenna beam width calculator

Views of the earth from various geo orbit positions

Reducing satellite interference

My animated views of Planet Earth

Satellite beam design

Select a satellite orbit long and height
Satellite orbit position (deg E) Orbit height:
geo=35786km   O3b=8063km
Enter the latitude and longitude of your proposed satellite beam centre, plus its diameter as viewed from the satellite.
Beam centre latitude (degN+, S-) Beam centre longitude (deg E)
Enter beam diameter(s). If circular beam then enter same number twice.
Ellipse minor axis
 diameter (deg)
Ellipse major axis
 diameter (deg)
Minor axis tilt
 0 - 180 clockwise

Example data inputs for you to try:


Manipulate the map centre and scale using the navigation buttons top the top left of the map or use the box below to centre on some named place.

This educational page is intended to help you experiment with different satellite beams and draw the coverage area.

The page only works with beams that are either circular or elliptical. If elliptical, enter minor and major diameters and the tilt of the minor axis relative to the equator. 0 to 180 deg clockwise and viewed from the orbit with North upwards.

Consider your service area. What is essential ? What is less important and maybe covered by a broader, weaker, beam or beam edge ? It is normal to make the beam edge about the -4 dB contour.

Work out the size of transmit and receive antennas needed on the satellite using the antenna beamwidth calculator link at the top of this page.

Hint: Point the beam down at the sub-satellite point to verify its diameter and, if elliptical, the shape and orientation.

Disclaimer Warning:  The results of this page may be in error.  The beam centres and beam shapes and sizes are approximate.

Use is entirely at your own risk.  Apply common sense and don't believe every number that comes out of a computer system!

Example satellite beam design with several dB contour levels

The above image is an example of what happens if you plot several elliptical beams, based on the same centre lat and long but with different beamwidths. To do this, first determine several pairs of elliptical diameter widths using the beamwidth calculator for different dB down levels.

This page is on the web site and is strictly Copyright Satellite Signals Limited (c) 2013 All rights reserved. Please report any copyright infringements to , also feedback on technical errors or problems with this page. Many thanks.

Page started 11 July 2013, last amended 29 Jan 2017