Jeppesen Marine Workboat Navigator 1.3 - Manual (Page 155)

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Glossary
Compass Rose
An image, overlaid on the chart,
which displays both magnetic and true
compass directions.
Course
The direction a boat is being steered.
Course Over Ground (COG)
Is the track of the boat over the ground
and is based on position changes.
CPA
See Closest Point of Approach
Cross Track Error (XTE)
The distance of a perpendicular line
drawn from the boat to an active route
leg. Determines how much the boat is
straying from the course of a Route.
Data Sentence
The unit of information sent between
peripherals and Visual Series,
conforming to the NMEA 0183
specification.
Datum Setting
Jeppesen Workboat Navigator assumes
that the GPS will be output position data
using the WGS84 Datum. The setting is
configured in the GPS.
Dead Reckoning
A method of navigation where known
values (position, course, speed, time
and distance to travel) are used to
calculate unknown values. Values such
as set and drift can also be incorporated.
Depth Sounder
See Sounder.
Deviation
Changes in the magnetic field due to
the ferrous composition of surrounding
objects affecting the measured direction
of magnetic North. Deviation is
measured as the angular difference in
direction between the actual magnetic
heading and the compass heading.
Distance To Passing (DTP)
The calculated distance to passing a
selected target, provided boat continues
on selected Route. Draft
The extent to which a boat protrudes
into water. The draft of a boat may vary
due to changes in weight and changes
in water salinity.
Drift
The drift and set combined result in
the cumulative effect of direction and
distance.
Electronic Chart System
A system comprised of:
navigation software
navigation data
system hardware
An Electronic Chart System is any
combination of hardware and software
that displays marine charts electronically
- like Jeppesen Workboat Navigator
operating on a Windows XP laptop.
The term ECS is used specifically when
ECDIS specifications are not met by the
software/hardware system.
Electronic Navigation Chart (ENC)
An electronic data file containing
information that could be used to display
a chart.
Electronic Security Key
A digital file that contains all current
Chart Permits and Unlock Codes for the
NavData regions you have purchased.
This file verifies to Jeppesen Workboat
Navigator NavData installer which charts
and supplemental data to decrypt and
load onto your system.
Estimated Passing Point (EPP)
The estimated location where your boat
will pass a specific target. Data for the
EPP includes the location of the passing
point by river abbreviation and River
Mile mark.
Estimated Time of Arrival (ETA)
The calculated arrival time to an
active mark or waypoint, assuming no
change in present course and speed or
weather conditions. This time is based
on computer clock time. For greatest
accuracy, make sure computer clock is
synchronized with real time.
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