MTR Science & Technology writer Tom Mulligan
reports from his subsea and maritime tech tour through eastern
Dartmouth, Nova Scotia based acoustics specialist company GeoSpectrum Technologies Inc, a producer of underwater acoustic transducers and systems, has been in operation for more than 20 years, supplying hydrophones and sound projectors to a range of customers in the marine and oceanography sectors, as well as providing consultancy services on acoustic systems integration and test procedures. End-user sectors include defense and homeland security, oil & gas, and environmental services. As well as standard products, GeoSpectrum can also provide customized products and is particularly recognized as a leading provider of systems for the marine mammal monitoring and ocean observation sectors.
Components designed and manufactured by the company are tested with a range of on-site equipment to ensure these meet customer requirements: this equipment includes pressure and environmental chambers and NIST-traceable calibration equipment, and the company has a production facility capable of manufacturing more than 1000 hydrophones a day.
GeoSpectrum's wide-band omnidirectional hydrophones include an integral, low-noise voltage- or current-signalling preamplifier and can be configured to operate over customer-defined bandwidths with required sensitivity and also allow for customizable gain. In addition, the depth rating for each hydrophone can be tailored to meet specific requirements to meet shallow- to deep-water requirements.
In addition to hydrophones, the company designs and manufactures electrodynamic sound projectors and has recently introduced its C-BASS family of very-low-frequency projectors. These are less expensive and smaller, lighter and designed to be more efficient than standard products. With their broad bandwidth, they can be used in a variety of applications where sound projectors could not previously be employed. The C-BASS systems may be used omni-directionally or in arrays to produce high-power sources with or without directivity and applications include their use as diver deterrents to protect marine assets; as VLF ASW systems; as a VLF calibration source; in AUV-based target emulation; for underwater navigation/GPS applications by providing a network of beacons; for acoustic and health monitoring purposes; and in VLF communication systems with a range exceeding 1,000 km.