Satellite Footprints and Coverage Maps Explained
A satellite footprint map shows where the satellite's signal reaches on Earth — and how strongly. Before you install a dish or buy a receiver, reading a footprint map saves you a lot of guesswork.
What a Footprint Map Shows
Contour lines on the map connect points of equal signal strength (EIRP). The inner contour is strongest; outer contours are weaker. Your location sits on one of those lines.
Reading the Contours
- Inner contour: a 45–60 cm dish is plenty.
- Middle contour: plan for an 80 cm dish.
- Outer contour: 90 cm or more, and expect rain margin issues.
Spot Beams vs Wide Coverage
Some satellites use spot beams — narrow, intense signals aimed at specific countries. These can be hard to receive outside their target. Other satellites use wide pan-European beams that cover everywhere at lower strength.
Where to Find Footprint Maps
Free satellite coverage maps are published by operators and enthusiast sites. Search for your target satellite (e.g. “Astra 19.2 E footprint”) and look for the contour map.
Why It Matters Before You Install
If you are on the outer contour, buying a 60 cm dish will cause endless rain fade. Check the map first and buy the right size once.
Footprints Change
New satellites have updated footprints. If you are using an old map, double-check — the newer satellite may have a stronger beam over your area.
The footprint map is your dish-size cheat sheet. Spend five minutes on it before you climb the ladder.
