Detecting and Locating Satellite Interference With Carrier ID and Geolocation
How continuous spectrum monitoring, Carrier ID, and geolocation systems work together to detect, identify, and locate sources of satellite interference.
This article is part of our Satellite Spectrum Interference & Congestion: Operator Field Guide
How Operators Detect and Localize Interference
The first line of defense is continuous carrier and spectrum monitoring. DSP-based carrier monitoring systems track carrier level, C/N, center frequency, bandwidth, modulation type, and symbol rate across dozens of carriers simultaneously. Software compares measured values against a database of expected parameters, raising alarms when values drift. These systems can record and replay historical spectrum snapshots and detect carrier-under-carrier situations and abnormal spectral shapes. This tells you something is wrong, roughly when it started, and which carriers are affected.
Carrier ID: Turning Mystery Carriers Into Known Terminals
Carrier ID embeds identification data directly into transmissions. Modern DVB-CID implementations carry mandatory fields (manufacturer ID, serial number) and optional fields (GPS coordinates, contact details). Special receivers at satellite operators decode CID without disrupting service. Regulators and industry groups have pushed mandatory CID for SNG and certain contribution links, with shared databases mapping IDs to operators and contact points. For NOCs, this converts a mystery carrier into a known terminal with a phone number.
Geolocation: Pinpointing the Source
When CID is not present or more detail is required, geolocation comes into play. Traditional systems compare the same interfering signal as seen through two satellites that share the relevant frequency, polarization, and coverage. Differences in arrival time, phase, and Doppler shift triangulate the source—essentially GPS in reverse. Newer single-satellite approaches analyze signal distortions on just one path, avoiding the need for a cooperating adjacent satellite. These systems can narrow an interfering source down to a few kilometers, giving regulatory teams and operators a concrete target for resolution.
Multi-Constellation Coordination
The interference story increasingly spans classical GEO and large LEO constellations. Studies have measured unintended emissions from LEO broadband constellations in protected radio astronomy bands, and collaborations like the SETI Institute-SpaceX partnership have emerged to protect observatories from direct-to-cell transmissions. These developments underline that interference detection and resolution increasingly require active cooperation across operators, regulators, and scientific users—not just internal NOC processes.