Septentrio

Septentrio designs high-precision GNSS receivers in Leuven, Belgium, and has built its reputation on one stubborn problem: what happens to satellite positioning when something, or someone, is deliberately breaking it. The company started in 2000 as a spin-off from imec, the Belgian microelectronics research institute, and it still develops its own tracking engine, firmware and positioning algorithms rather than buying a chipset from a third party.

The portfolio runs across four hardware shapes. Receiver modules are the smallest, sold to manufacturers embedding positioning inside their own products. mosaic-X5 is the long-running multi-band module with 448 hardware channels, and the newer mosaic-G5 family extends it downward in size and power draw with variants aimed at different jobs, including mosaic-G5 T for timing and mosaic-G5 P3H for dual-antenna heading on small unmanned aircraft. mosaic-H adds dual-antenna heading in the original form factor. Above the modules sit OEM boards such as the AsteRx-m3 Pro and Pro+, meant to drop into a customer enclosure for base station or rover work.

Rugged, fully housed receivers make up the third group. AsteRx-U3 is the flagship integrated dual-antenna unit with wired and wireless communications, AsteRx SB3 Pro+ is an IP68 field receiver, and AsteRx SBi3 Pro+ folds an inertial measurement unit into the same box so the position solution keeps running through short GNSS outages. AsteRx-U Marine is the vessel positioning and heading configuration. The fourth group is reference infrastructure: the PolaRx5 line of geodetic receivers, including the battery-powered PolaRx5e and the PolaRx5S built for ionospheric and scintillation monitoring. Those sit in permanent monitoring networks, and the US Geological Survey has deployed them on Volcano Hazards Program stations in Alaska and internationally. PolaNt antennas, including choke ring models, pair with them, and RxTools is the configuration, logging and analysis software that ties the hardware together.

Running through all of it is AIM+, Septentrio's interference mitigation layer. It samples the RF front end and suppresses jammers ranging from simple continuous narrowband transmitters through chirp jammers and high-powered pulsed sources, with higher tiers adding spoofing detection. That is the reason a commercially focused Belgian receiver house turns up in defense conversations at all. Septentrio markets an assured PNT line aimed at navigation warfare conditions, and mosaic-X5 is listed on the US Blue UAS Framework, which is how a good number of Western drone programs end up specifying it.

It is worth being precise about what Septentrio is not. It is not a defense prime. The bulk of the business is surveying, precision agriculture, construction and mining machine control, marine, timing infrastructure and industrial autonomy, and defense is a growing slice rather than the core. Around 120 people work there, with regional offices in Torrance, Shanghai and Yokohama.

Ownership changed in 2025, when Hexagon AB agreed to buy the company and closed the deal that year. Septentrio now sits alongside NovAtel inside Hexagon's positioning business, giving the group two independent high-precision GNSS engineering teams, and the Leuven operation has continued to release products under its own brand since.