Low 5 Array: Passive Acoustic Array

Under ice detection using very low frequencies

The Low-5 array is a passive acoustic array designed specifically for low frequency underwater detection and communication including under ice operation. The Low-5 array’s unique low displacement, low power, low drag, high speed-stability and high-performance design optimize it for employment in unmanned, persistent underwater surveillance and communication missions. While low frequency requires longer arrays normally driving higher drag, displacement and power solutions, the unique Low-5 array characteristics make it possible for even small unmanned maritime systems such as AUVs and wave glider USVs to deploy a capable low frequency array for extended durations.

Description

The Low-5 array can be used for persistent long-range detection and communication including under ice in environments such as the Arctic where the low frequency benefits of reduced propagation loss are critical. It can be towed by underwater unmanned systems such as AUVs to perform passive acoustic monitoring or be used as active-receive arrays for multi-static operation. They can also provide the unmanned platform a means for long range communication enabling them to receive mission commands or remote-activation triggers across ranges of hundreds of kilometers. The low power consumption and speed-stability of the Low-5 array render it a viable solution for AUVs as well as persistent USVs. The Low-5 array can also be deployed statically in required locations including under-ice installations.

Summary

The Low-5 array leverages GeoSpectrum’s vast experience and unique ability to optimize underwater acoustic arrays achieving cutting-edge performance. The Low-5 array has special utility as a compact, high-performance low frequency passive acoustic payload for unmanned maritime systems enabling long-range underwater communications and detection. At-sea, trials using L-5 and GeoSpectrum VLF acoustic source – C-Bass, exhibited low-frequency communication ranges exceeding 680 km, a range constrained only by the limits of the trial.

Frequency Range
10-1000 Hz
Overall length
575.5 m (array length 525.5 m). Scaleable
Operational speed (if towed)
1-3 Knots
Deployment speed
3-5 Knots
Electronic power consumption
< 3 Watts
Operational depth
400 m
Max depth
600 m
Operational temperature
-3 to +35° Celsius
Storage temperature
-50 to +60° Celsius
  • Low displacement
  • Low power consumption
  • Low drag
  • High-speed stability
  • High depth rating
  • High performance miniaturized hydrophones and preamplifiers
  • Designed for high Directivity Index in low frequencies
  • Designed for prolonged reliable deployment at sea including arctic under-ice environment
  • Designed and proven for low self and flow noise
  • Hydrodynamically shaped, high strength, lightweight, corrosion-resistant, UV and seawater resistant sensor nodes
  • Acoustic and non-acoustic sensors
  • Scale-able design
  • Optional data logger and acoustic processing application
  • Array cable
  • Sensor nodes each containing
    • Hydrophone
    • Non-acoustic sensors
    • Inertial Measurement Unit (IMU)
    • Electronics
  • Data logger
  • Optional sonar processing SW