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Fine Profile
Instrument setup that prioritize the highest possible resolution at the expense
of the maximum range achievable.
Firmware
Internal software of the instrument, as opposed to the instrument software
running on a PC. New firmware is posted on the Nortek site. You will need to
register to get access, but access is otherwise free of charge.
Ice Draft (keel)
Measures thickness of ice. Ice draft = Water depth - Distance to Ice
Ice Drift
With the correct firmware and license, measures velocity and direction of ice
drift.
Internal sampling rate
Rate of sampling for internal sensors. Refer to the specific instrument
brochure for details.
LED
Light Emitting Diode, visible from the outside of the instrument. The LED can
be set to blink for every sample (On), blink for the first 24 hours of deployment
(On for 24h), or never (Off).
License
Different capabilities of the instrument are protected under licenses which can
be purchased. Contact your sales representative for more information.
Register purchased licenses while connected to your instrument under
Instrument > Licenses. Licenses that are ordered with the instrument are
already registered.
You will not need a license when updating the firmware version.
NMEA
Standard data format defined by the National Marine Electronics Association
Noise floor
The amplitude of the internal noise of the instrument. This will limit the
minimum detectable signal that can be received.
Ping
Same as a single transmit pulse.
Precision
The value given is a theoretical estimate of the precision of the velocity
measurements based on how the instrument is set up. The nominal value is
given for the horizontal components in a default instrument acoustic beam
configuration. In order to improve the precision the user may consider one of
the following options: (1) larger cell sizes, (2) longer average interval (3)
reduced velocity range, or (4) increased measurement load
Sampling rate
Specifies the rate at which data is output
SDU Coordinates
Speed - Direction - Up.
Sidelobe
The acoustic beams focus most of the energy in the center of the beams, but
a small amount leaks out in other directions. Transducer sidelobes are rays of
acoustic energy that go in directions other than the main lobe. Because sound
reflects stronger from the water surface than it does from the water, the small
signals that travel straight to the surface can produce sufficient echo to
contaminate the signal from the water.
Signal strength
Strength of return signal, presented in dB.
Sleep mode
The instrument is not actively collecting data
SNR
SNR is the Signal-to-Noise ratio and is a data quality indicator
XYZ Coordinates
Cartesian coordinate system. A positive velocity in the X-direction goes in the
direction of the X-axis arrow. The X-axis points in the same direction as beam
1. Use the right-hand-rule to remember the notation conventions for vectors.
Use the first (index) finger to point in the direction of positive X-axis and the
second
(middle) finger to point in the direction of positive Y. The positive Z-axis will
then be in the direction that the thumb points.
