JRC JLN-650, Instruction Manual, Page: 12 / 190

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Glossary
Tidal current direction: Direction of the current flow. "It flows and leave" direction is indicated usually.
North up bearing:
Bearing displayed with true north at the top of the display.
Head up bearing: Bearing displayed with bow at the top of the display.
A, B, C, D and E layers: Five depths at which speeds and other information are measured. Transducer
beams are transmitted in four directions; port ahead, starboard ahead, port astern
and starboard astern.
Image figures when three layers (A, B, and C
layer) are measured.
D and E layer join further for five layers.
Absolute tidal current: Direction and a speed of the tidal current to the sea bottom (ground).
Relative tidal current: Direction and a speed of the current in A layer and B layer when based on the tidal
current in E layer. Further is made a standard layer of drum either in not E layer but
the A-D layer according to the setting.
Bottom tracking mode: The direction and the speed at the sea bottom against are measured in bottom
tracking mode. When measuring it in the bottom tracking mode, it is displayed on
the current measurement screen, "B
・
T". It automatically changes into the water
tracking mode when it becomes impossible to pursue because the sea bottom
became deep.
Water tracking mode: The direction and the speed to the set E layer (It is possible to set it also in the A-D
layer) are measured in the water tracking mode. When measuring it in the water
tracking mode, it is displayed on the current measurement screen, "W
・
T".
Trip: It is a distance sailed from a certain point to the present place. When zero resets
are executed pushing "Reset" key in this device, the starting point of trip is set.
Timer: It is a distance that passes from a certain point to the present place. The timer starts
when zero resets are executed pushing "Reset" key in this device.
Sea Surface
Sea Bottom
A Layer
B Layer
C Layer