Building a DIY Satellite Receiving Station at Home

At this very moment, multi-million-euro satellites are passing overhead, broadcasting Earth imagery and weather data down to anyone equipped to listen. These transmissions are completely unencrypted, blanketing entire continents on frequencies that can be captured using roughly 100 euros worth of equipment and a balcony facing the sky. This open access applies to Earth photos, weather feeds, maritime and aviation tracking, amateur radio, and even live feeds from the International Space Station.

This journey began as a casual spark of curiosity, opening up a new frontier of space exploration right from home. What started as a simple test evolved into a distributed receiving station spanning two countries, a resurrected old laptop acting as a server, a father on a ladder in Théding while the author watched from Barcelona, and the pursuit of a drifting geostationary satellite. The project remains an ongoing endeavor, grounded in the distinction between two fundamentally different types of weather satellites.

The first category consists of polar-orbiting satellites. Operating at low altitudes of a few hundred kilometers, they zoom rapidly from north to south while the Earth rotates underneath, eventually sweeping across the entire globe. These are the primary targets tracked in this story: Russia's METEOR-M series, orbiting 800 kilometers above ground and broadcasting in the 137 MHz VHF band.

The catch with polar orbiters is their brief visibility window. Each satellite rises above the horizon, traces an arc overhead, and disappears within ten to fifteen minutes, leaving a strict time limit to capture its transmission before it moves out of range. Missing a pass means waiting another one to two days for the next orbit. The second category features geostationary satellites positioned 36,000 kilometers away in an exact synchronization with Earth's rotation, making them appear perfectly stationary in the sky with continuous broadcasting. They operate on the L-band around 1.7 GHz, presenting an entirely different receiving challenge leading up to the final encounter with the Elektro-L3 satellite.

Stock photo for illustration only, not from the actual event

The mission kicked off with the purchase of an inexpensive RTL-SDR USB dongle bundled with a small telescopic dipole antenna. The antenna was deployed on the terrace, pointed roughly toward the sky, and set to record during an expected METEOR pass. These receivers originated around 2012 when tinkerers discovered that simple DVB-T television tuner dongles could expose raw radio sample streams, transforming a low-cost TV stick into a flexible software-defined radio.

When the satellite passed overhead right on schedule, the recording was captured and run through the decoder. The resulting output initially resembled a thin black chopstick line rather than a clear picture. However, this raw artifact provided crucial diagnostic insight: it captured the exact moments when the satellite reached its highest and closest point, briefly piercing through the ambient urban radio noise, whereas lower passes remained drowned out by static. This initial diagnostic failure laid the groundwork for solving the signal reception challenges ahead.

Source: Dev.to