Compact sub-bottom profiler, GeoPulse
GeoPulse Compact is a technically advanced sub-bottom profiling system. Its digital processing and waveform selection technology enables the appropriate pulse-shape, power signature and configuration to be selected for the job in hand, whether it’s mapping the geology in deep oceans or determining mud thickness in a silted harbour.
The new GeoPulse Compact system combines the best features of continuous wave (Pinger) type systems and frequency modulated pulses in a unit which requires only 11% of the power requirements of previous systems. The system utilities very low noise, state of the art, ADC and amplifier technology. Massive oversampling of the raw signals (800kHz), combined with advanced FPGA based decimation and processing allows the receivers to achieve over 100dB of noise free dynamic range.
The system is operated directly from a computer using the supplied GP1000 software, which interfaces to the deck unit via Ethernet. The sonar electronics are mounted close to the transducers in all deployment options and the signal is transmitted to the deck unit via a lossless digital connection. Data is acquired with the transmit transducer and with a fixed hydrophone, allowing the operator to use the best signal for the job at hand.
The Deck Unit receives serial inputs from GNSS as well as a PPS input. The deck unit interfaces to the towfish through a soft tow cable. Power is supplied by a 10-30V dc connection allowing the system to be operated from battery power on small vessels.
The waterproof electronics module is manufactured in aluminium and is rated to 1000 metres water depth. Its internal electronics generate and transmit the waveforms selected by the user. The return signals are received either from the integrated hydrophone or from the transducer and are instantly digitised prior to being routed to the Deck Unit via an ADSL link.
Transducers and Hydrophone
The transducer is a double resonant stack design which operates efficiently over a wide frequency band of 2 - 18 kHz and has a flat response over the range 5-18 kHz.
The integrated single channel hydrophone utilises 7 high-spec elements to capture the return signal and route it via an inline preamp to the subsea electronics where it is digitised.
It is available in a towed version or as an over the side mounted version.