Kongsberg Simrad SN90 Reference Manual page 531

For most purposes, UTC is used interchangeably with GMT, but GMT is no
longer precisely defined by the scientific community. [...]
The current version of UTC is defined by International Telecommunications
Union Recommendation (ITU-R TF.460-6), Standard-frequency and
time-signal emissions and is based on International Atomic Time (TAI) with
leap seconds added at irregular intervals to compensate for the slowing of
Earth's rotation. Leap seconds keep UTC within 0.9 seconds of universal
time, UT1.
Wikipedia, Copied June 2014
Related functionality
Top bar
The top bar is located at the top of the display presentation and stretches from
the far left to the far right.The top bar gives you fast access to key functionality
and navigational information.It provides buttons for hiding and showing the
menu, making screen captures, opening the
context-sensitive help.
Menu
Unless you need to make frequent changes to the operating parameters, you may
want to hide the menu from the display presentation. This gives you more space
for echo information. To hide the menu, select
the menu, select
shown on the left or right side of the display presentation if you move the cursor to
that position.
Navigational information
The navigational information is located in the middle of the top bar. These fields
are separate read-outs. They present information related to the navigation of the
vessel and operation of the SN90 system. The information shown on the top bar
must not be used for vessel navigation.
Bottom bar
The bottom bar is located at the bottom of the display presentation and stretches
from the left side to the right side. The tabs on the bottom bar allow you to choose
presentation mode. The bottom bar is available all the time.
Related topics
Defining settings related to user preferences and individual customizing, page 156
Menu, page 300
Navigational information, page 307
Bottom bar, page 375
Functions and dialog boxes, page 416
Display menu: functions and dialog boxes, page 438
Display Options dialog box, page 444
381294/E
one more time. When the menu is hidden, it is temporarily
Menu
Functions and dialog boxes
dialog box, and opening
Messages
on the top bar. To retrieve
Menu
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