The HTI Digital Array System is a hydrophone array system designed for use in vertical cable applications, bottom cable surveys, and deep towed streamers. The system operates in water depths up to 6000 meters and can accomodate up to 96 channels at a sample rate of 0.25 to 2 milliseconds.
Each of the nodes, or channels, in the digital vertical cable is made up of a hydrophone and a 24 bit Delta-Sigma A/D converter electronics module. Nodes are inter-changeable and designed to be easily replaced in the field. An acoustic position system is integrated into each node. The spacing between nodes and overall cable length is determined by the user. Power consumption by each node has been minimized to facilitate power transmission down the cable from an autonomous buoy battery pack.

    Vertical Array System
  • The total system consists of a vertical two conductor hydrophone cable anchored to the sea floor and connected by an S-tether to the autonomous recording buoy. The recording buoy communicates with the shipboard interface via radio telemetry.
    Towed Array System
  • The total system consists of a horizontal hydrophone cable which is a coaxial neutrally buoyant cable with a maximum operating depth of 6000 meters. The array may include heading and depth sensor modules. Data is integrated in the sub-surface towfish electronics. Data from ancillary sensors are multiplexed with the acoustic data by the towfish electronics and transmitted to the surface.

System Specifications:
Sensitivity -194 dB re: 1V/µPa
Self-Noise 0.07 µBar RMS
Dynamic Range 117 dB
Frequency Response 2 Hz - 3000 Hz
Directivity Omni-directional to 2 kHz
Operating Depth 10,000 feet

    Emphasis On:
  • Systems approach
  • Light weight mooring system
  • 1 to 96 channels configurable
  • 24-bit Delta Sigma A/D converter at each hydrophone channel
  • Identical node modules
  • Motion-insensitive hydrophones
  • Downlink telemetry to nodes
  • Optional GPS time synchronization