Frequently Asked Questions
Here you can find the answers to
many of our most frequently asked questions. If your question is not answered
here, please send us an
email
with your question.
What is the difference
between CASS, FLS, and OAS sonar systems?
Can the sounds levels
and frequencies hurt marine life?
What does Water Depth
performance mean?
What is the difference
between Water Depths and Detection Range?
How deep does the FS-3
look below the water?
In what sea conditions
will the FS-3 work?
Can the FarSounder
systems tell the difference between a rock and a whale?
What types of targets
can the FS-3 detect?
What is angular
resolution?
At what frequency does
the FS-3 sonar operate?
How often can the FS-3
system generate a complete picture ahead of the vessel?
Does the FarSounder system
have any mechanical (moving) parts?
Hasn’t sonar technology
existed for a long time? How is FarSounder’s technology different than
existing technologies
and products?
What is an example of a
1D sonar?
What is an example of a
2D sonar?
What is the difference
between CASS, FLS, and OAS sonar systems?
CASS (collision avoidance sonar system), FLS (forward looking sonar), and OAS
(obstacle avoidance sonar) are all names which can be used interchangeably when
describing a sonar system which looks ahead and is used for navigation. Although
there are many products on the market with these names, only FarSounder’s
products create a complete 3D image ahead of the vessel at
navigationally significant ranges with a single ping.
Can the sounds levels and
frequencies hurt marine life?
No. We operate at similar sound levels and frequencies as dolphins. In fact, the
National Marine Fisheries Service sponsored the development of our technology to
non-invasively study whales.
What does Water Depth
performance mean? What is the difference between Water Depths and Detection
Range?
Water depth performance is how far away (in multiples of the depth of water
below the transducer) depth information can be measured. THIS IS THE KEY FOR
SHALLOW WATER OPERATION.
Detection Range is how far away a target of a certain size can be DETECTED. But
detection is different from localization.
FarSounder can accurately
tell you the depth of a target consistently for at least 8 water depths
(In practice we have many data sets of 12-18 water depth performance for
some bottom types and conditions). Beyond FarSounder's water depth performance capability, if a big target is detected, range and bearing to the target can
be calculated and displayed. However, the depth of the target is not necessarily
known.
Just as RADAR doesn't give altitude above the water but can still be a useful
tool, detection at beyond water depth capabilities can also be a useful tool.
How deep does the FS-3
look below the water?
The current FS-3 design is limited to 50 meters (~150 feet) maximum depth. This
is a design choice that was made because most vessels that have a draft of more
than 50 meters are usually called ship wrecks (a little sonar engineer humor).
The core technology is very flexible and can be customized to meet your needs if
greater than 50 meters depth is required.
In what sea conditions
will the FS-3 work?
The current product has been designed to operate even under moderate sea
conditions. Of course, in larger wave environments, smaller surface targets will
be lost in the surface clutter.
The FS-3 user interface includes a Surface Clutter removal control where the
user can specify the clutter removal setting. Reducing surface clutter noise has
the cost of missing small surface target detections.
LIKE ANY MARINE ELECTRONICS SENSOR, the FS-3 will not function well under the
most extreme conditions. Quantitative results depend upon many factors
including: hull mounting method, sea state, vessel speed, water temperature,
wind speed, etc. Generally, the deeper the Sonar Head is installed the better
the system operates at higher sea states.
Can the FarSounder systems
tell the difference between a rock and a whale?
Currently, our technology only performs LOCALIZATION. That is to say, we can
tell you WHERE something is. Telling you WHAT something is called
CLASSIFICATION. Classification is a technology that we are considering
integrating into future products.
In fact, FarSounder has a co-operative research and development agreement (CRADA)
with the Naval Undersea Warfare Center (NUWC) for doing just this.
What types of targets can
the FS-3 detect?
The FS-3 detects targets that are navigational obstacles for
vessels from 15 metres (50 feet) and up. In general, if a boat cares about hitting the object, we
can detect it. If the boat does not care about hitting the object, we do not
detect it well. For example, we can see navigation buoys but we cannot see most
fish well (although the fish may care about being hit by an 50' boat, the 50'
boat usually doesn't care).
Of course, FarSounder's core technology is very flexible and easily
configurable. We can design a custom system to detect objects of almost
any size depending upon your needs.
What is angular resolution?
Angular resolution is a property of a receive transducer array and its
associated beamformer. Angular resolution is the ability to discern objects at
different angles. This is important in separating objects from each other. In
general, traditional signal processing techniques are able to generate angular
resolutions of approximately 50/L where L is the array’s length in wavelengths.
FarSounder generates angular resolutions one to two orders of
magnitude better through the use of proprietary processing algorithms.
At what frequency does the
FS-3 sonar operate?
FS-3 operates at approximately 60kHz.
How often can the FS-3
system generate a complete picture ahead of the vessel?
Unlike some systems which take up to 90 seconds to complete a large field of
view scan ahead of the vessel, the FS-3 generates a high resolution, full
field-of-view image once every 2-3 seconds. FarSounder technology is able to
give the user a near real-time picture ahead of the vessel.
Do FarSounder systems have
any mechanical parts?
No. Our systems are entirely solid state and do not have any moving parts.
Hasn’t sonar technology
existed for a long time? How is FarSounder’s technology different than existing
technologies and products?
Traditional sonar technology and products are able to generate 1D and 2D images.
FarSounder’s approach to sonar is fundamentally different than traditional
sonars as it generates 3D images in real-time for a large field-of-view
ahead of a vessel. We display a complete picture and
as well as deliver the most basic and important piece of information for marine navigation:
What is ahead of the vessel.
What is an example of a 1D
sonar?
A simple depth-sounder or echo-sounder is a 1D sonar. These systems simply tell
the user the depth directly below the sounder. They are not able to warn the
user about the rock, submerged shipping container, sandbar, whale, boat, or
other obstacle ahead of the vessel. In the very worst of cases, if the sounder
is located in the stern of the ship, the bow of the ship may actually be
grounded on an obstacle while the sounder continues to tell the operator that
there is still navigable water below.
What is an example of a 2D
sonar?
Other systems that are called forward looking sonars do actually look forward
but they are only able to discern information in 2 dimensions. Generally they
can tell the user that there is an object at a particular bearing and range, but
they cannot tell the user whether the object is at the surface, in the water column,
or on the sea bottom. They simply have one horizontal slice through the water.
These systems are unable to tell the user if the object is 5 feet below the
surface or 50 feet below the surface. Some 2D systems even go as far as to have
a second array giving one vertical slice through the water. However, in this
configuration, the vertical slice can only give the user information about the
range and depth of an object, it cannot tell the user at what bearing the object
is located ahead of the vessel. Even the most advanced 2D system cannot
correlate between the vertical and horizontal slices.
