NorthStar 8000i System Operation Manual page 205

streamed video and audio
Video and audio is encoded into MPEG2 format and then sent (streamed)
across the network to devices that decode the signal.
sumlog
An instrument that records the boat speed and the distance traveled. See
also Log which is often used an abbreviation.
T
thermocline
A sudden change of temperature over a short vertical distance.
Threshold
An adjustable setting that specifies the weakest echo to be displayed.
Track Library
A list of tracks recorded and stored on the database.
Transducer
Underwater instrument that generates ultrasonic pulses then interprets the
echoes returned from solid objects.
True Motion
The chart is fixed, and your boat moves across the chart at the appropriate
speed and heading.
U
ultrasonic
Sound waves with a pitch above the upper limit of human hearing.
US Gallon
A unit of volume equal to 0.833 Imperial gallons.
W
waterproof
Protected from water damage by the use of seals for apertures or chemical
treatment.
waypoint
A navigation position defined by latitude and longitude. Usually a
destination or point of reference. On a chart, a route normally consists of
one or more waypoints.
Waypoints Library
A list of stored waypoints in the database.
Northstar 8000i Operation Manual
205