Robust offshore operations thanks to anti-jamming technology

Image credit: DEME

The dredging environmental and marine engineering giant DEME is an international market leader for complex marine engineering works. Aboard DEME’s ships AsteRx4 receivers are integrated to provide high-accuracy positioning using satellite PPP corrections.

Creating land for the future, is the slogan here at DEME and this is thanks in part to the accuracy and robustness of Septentrio’s GNSS receivers.

Lorentz Lievens
Head of Survey Department, DEME

Commercial marine dredging operations are essential to keep busy waterways and harbours always open for international trade. However, these operations were significantly impacted by radio transmissions, used for military exercises, which were ‘leaking’ into GNSS signals around the commercial waterways. The result: major periodic in-band interference, knocking out the complete L2 band (both for GPS and GLONASS) on all commercial receivers every 7 seconds for a few hundred milliseconds.

A chirp jammer interferes with GNSS signals in a 400m radius. Left image: without AIM+ / right image: with AIM+ turned on

With the activation of Advanced Interference Mitigation (AIM+) countermeasures in both land-based and ship-based receivers, all of the in-band interference was filtered out from the GPS and GLONASS L2 bands. This resulted in high-quality GNSS signals being available for the high accuracy real-time positioning needed for dredging operations.

Advanced Interference Mitigation (AIM+) allowed us to ignore local GNSS interference and continue our dredging operations.

Lorentz Lievens
Head of Survey Department, DEME