The Small Seismic Positioning Transponder (SST) has been specifically designed for Ocean Bottom Seismic cable positioning operations, where high-performance, small-size, low-cost and rugged design are important operational factors.

Available in 1,000 and 2,000 metre depth ratings, the SST is designed for use with Sonardyne’s Ultra-Short Baseline (USBL) acoustic positioning systems Ranger 2 USBL.

As these systems measure both range and bearing to the SST transponder, only one overhead pass of the cable is required to position the transponder. This is instead of the two passes currently required for range-only transponder systems.

The use of USBLs and SSTs in this way results in considerable savings in vessel time, introducing new standards of efficiency for seismic operations.

Where the SST is to be left attached to a cable and then reeled onto a drum, the option of a stainless steel outer body is available. This provides increased durability and crush resistance for the unit in harsh and dangerous environments.

Another feature of the transponder is its programming flexibility. Any one of 410 addresses and 16 reply channels, providing 6560 identities, can be programmed using a Type 8037 MF Command Unit. This lends itself to the marking of seismic cables and other applications demanding dense coverage.

The SST can also be used as a permanent long-life marker transponder, or a small, low-cost USBL tracking beacon for small ROVs.