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Hydroflown Sensor for
Underwater Situational Awareness
Application Leaflet
Microflown Maritime
PO Box 2205
6824 BV Arnhem
The Netherlands
maritime@microflown.com
Hydroflown Sensor for Underwater Situa onal Awareness
The Microflown sensor is an acoustic particle velocity sensor that
operates in air measuring the particle velocity in a bandwidth of
0Hz up to 120 kHz. The sensor has been developed and sold
worldwide for many applications over the past few years. The
main applications are found in automotive, aerospace and
defense industries.
In recent years, developments have taken place to adapt the
particle velocity sensor for use under water. This type of sensor is
called a Hydroflown. The Hydroflown sensor is packaged in a
small oil filled container for use underwater.
This underwater sensor probe contains three orthogonally
placed Hydroflowns and when combined with a conventional
hydrophone is a true Acoustic Vector Sensor (AVS). The probe is
80mm long and 30mm in diameter. The direction of arrival (DOA)
of a sound wave is measured in one location.
The small size of Hydroflown probes allows installations on
several platforms such as below buoys, or surface vessels, on
bottom-mounted platforms, submarines, UUV's, sonobuoys,
etc.
There are numerous applications like threat detection (and
target acquisition), oil exploration, navigation (i.e. of small
autonomous unmanned underwater vehicles), underwater
communication, noise radiation tests, environmental
monitoring, etc.
The DOA is derived from the level differences of the Hydroflown
signals caused by the sensor's inherent polar directivity. Hence,
the technique is independent of frequency and of array size,
such as with linear arrays. This feature makes the sensor
especially suited for DOA determination at lower frequencies.
During recent sea trials the Hydroflown sensor was shown to
work in realistic underwater situations with high sensitivity in the
lower frequencies. This is an interesting feature since other
array systems, pressure gradient sensors and accelerometers
work better at higher frequencies and not so well at low
frequencies.
The Hydroflown sensors operate in 3D, so problems with leftright ambiguity as experienced with linear arrays are nonexistent.
Applica on features
Underwater Acous c Vector Sensor
Measures Acous c Par cle Velocity
Small Size and Light-Weight
Good Low Frequency Behaviour
- Not dependant on linear array size
ü Full 3D Situa onal Awareness
- Complete direc onality (also for low frequencies)
- Reports bearing, eleva on and range
- No le -right ambiguity as with linear arrays
ü Passive System
- Hard to detect
ü Applicable Pla orms:
- Buoys, Bo om Mounted Pla orms, Submarines,
Unmanned Underwater Vehicle (UUV), sonobuoys, etc.
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Microown Maritime, PO Box 2205, 6824 BV Arnhem, The Netherlands
W: www.microown-maritime.com E: maritime@microown.com T: +31 880 010 890