GNSS and GPS: which is best for navigating underwater DPVs?


When you submerge underwater there are few distinctive points of reference and divers risk losing their sense of orientation. This makes it important to equip yourself with the best instruments for establishing your location and identifying the direction you want to go.

In response to this requirement, the Suex research team continue developing new possibilities for underwater navigation to provide their DPVs with systems for enhance diving enjoyment, underwater exploration, and safety.

In this respect, the Sinapsi nose unit integrated into a DRIVe system provides extremely useful information for assisting underwater navigation, with precise positioning thanks to the use of a GNSS system.

What is GNSS and why is it important for scuba diving?

By now nearly everyone knows the Global Positioning System or GPS, a network of 32 satellites (24 active and 8 in reserve) managed by the United States and enabling positional location of devices by trilateration.

Operation of GPS involves three components: a network of space satellites, eight terrestrial control stations that monitor and update the satellites, and individual users with GPS devices.

When a user device issues a request to calculate its position, a signal is sent to the three nearest satellites. The transmission times to reach the three satellites are integrated, making it possible to pinpoint the spatial coordinates of the device on Earth.

However, GPS is not the only system for locating devices on the surface. There are three other active networks, including the European Galileo with 24 satellites, the Russian GLONASS with 24 satellites, and the Chinese BeiDou with 35 satellites, while India is currently developing a fourth.

The Global Navigation Satellite System (or GNSS) includes all the positioning systems mentioned above, and so using it gives access to a satellite network almost four times as numerous as GPS alone, making it possible to:

  • More precisely locate the device signal on the surface.
  • Maximize cover so that there are always three satellites nearby to link to wherever you are.
  • Minimize the risk of malfunctions, given the redundancy of the satellite population.

Basically, GNSS positioning is superior to GPS and this is why we chose it for Sinapsi.