GPS transponder - Seatrack 330

Designed to withstand a harsh environment

The environment on a seismic source is extremely challenging for all types of electronics. Firing the air guns may cause high-energy shocks of more than 50G with 10 ms duration. Repeated every few seconds, day and night, for periods of several months gives new meaning to the term shock exposure. Seatrack 330 is designed to withstand this harsh environment.

The electronics is fitted into a steel compartment, which is further protected by double polyethylene housing. This makes the Seatrack 330 resistant against all types of shocks and waterproof down to more than 50 meter.

Mechanical protection is not enough. Shocks of more than 20G will normally cause temporarily loss of lock of the GPS satellites. This ruins position accuracy especially when using carrier phase measurements or RTK.

A damping method reducing the high-energy shock exposure of the GPS antenna and receiver by more than factor of 2.5 has been developed. This enables the Seatrack 330 GPS receiver to continuously maintain track even during firing of the air guns. The robustness is verified by running unit through more than 1.000.000 repeated shocks. The test unit went through this exercise without one single failure.