What Is Gpredict and How Do You Track Satellites With It?

Gpredict is a free, real-time satellite tracking and orbit prediction application for Linux, Mac OS X, and Windows. It is designed to show where satellites are now and when they will pass over your location, so it suits anyone who wants to follow amateur radio satellites, weather satellites, or other tracked objects without paying for software. The official site at oz9aec.dk is currently under construction, so the software itself is best obtained from its established distribution channels rather than from that page.

What Gpredict does

Gpredict combines two related jobs:

• Real-time tracking — it continuously calculates and displays satellite positions as they move.
• Orbit prediction — it projects future positions so you can see upcoming passes over your ground station.

This makes it useful for planning observations, radio contacts, or antenna pointing, because you can look ahead instead of only watching the current position.

Supported platforms

Gpredict runs on the three major desktop platforms named by the project:

Because the project website is under construction, use your operating system's package manager or the project's established download locations to get the current version.

How to track satellites with Gpredict

1. Install the application

Install Gpredict using the method appropriate to your platform. On Linux this is typically a package manager; on Windows and Mac OS X it is a downloaded build. The expected result is that Gpredict launches and shows a default ground station and module layout.

2. Set your ground station

Your location determines every pass prediction. Enter your latitude, longitude, and altitude so Gpredict can calculate when satellites rise above your horizon. If your position is wrong, every pass time will be wrong.

3. Add satellites and update orbit data

Satellites are tracked using TLE (Two-Line Element) data, which describes their orbits. You need to:

• Add the satellites you care about to a module.
• Update the TLE data regularly, because orbits change over time.

Stale TLE data is the most common reason predictions drift or look wrong. Refresh it before relying on any pass.

4. Read the tracking and prediction views

Once configured, Gpredict provides:

• A map view showing satellite positions and ground tracks.
• Pass predictions listing when a satellite rises, reaches maximum elevation, and sets for your location.
• Tracking displays for following a selected satellite in real time.

Use the pass list to plan ahead, and the map and tracking views to follow the satellite as the pass happens.

Common setup issues

• Wrong pass times — almost always a ground station location error or outdated TLE data.
• Satellite missing from predictions — the satellite may not be added to the active module, or its TLE may not have been updated.
• No passes shown — check that your location is set and that the satellite's orbit actually passes over your latitude.

Where to get help

Since the official site is under construction, look for the project's documentation, user community, and distribution channels for installation help and troubleshooting. The application's own help resources and the amateur satellite community are the practical places to resolve setup problems.