Furuno FMD3100, Руководство оператора

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19. RECORDING FUNCTIONS, PLAYBACK FUNCTIONS
19-3
5. If you selected [Manual] at step 3, enter latitude and longitude position and com-
ment (optional), then click the [Record] button.
The [Position Event] window shows the position at
the moment the [Record] button is clicked. The posi-
tion is recorded to the [Voyage] log.
6. For [LOP], see the description below.
A plotted line on which a vessel is located, deter-
mined by observation or measurement of the range
or bearing to an aid to navigation or other charted element. Two or more simulta-
neous observations can be combined to produce an estimate of the ship's current
position. If the position is based on only two observations, it is an "estimated po-
sition" (EP); otherwise it is called a fix. A maximum of 6 observations can be en-
tered to obtain a fix.
Basic operation : Coordinates of the aid to navigation can be entered into dialog
boxes or they can be selected graphically on the chart:
• S57: Click on a charted object (beacon, light, buoy etc.) or any location. De-
scription of the object appears above coordinate boxes.
• ARCS: Click anywhere in the chart.
Default values for bearing and range are approximated from ship's current posi-
tion information. The time of observation is stopped when the object is selected
(or when the [Add] button is clicked). Click the [Add] box to include the observation
in the fix computation. The counter shows "new/1", at the input of the second ob-
servation. The word "new" indicates that the observation currently displayed is not
yet included in the fix computation, and it appears as a dashed line or ring on the
chart. The added observations can be edited or deleted after selecting them at the
counter. When at least two measurements are entered, the EP or fix is computed
and the coordinates are shown in the top part of the dialog. To show a position
symbol on the chart, click the [Record] button. In the case of an EP, the letters EP
are shown on the right side of the coordinates. If a valid position estimate cannot
be obtained, a message is displayed under the coordinates. This may happen, for
example, if the lines / circles have multiple crossings that are far apart, or if two
lines are nearly parallel or don't intersect at all. The accuracy limit (estimated stan-
dard error) is 1.0 NM. If the estimate is valid, the [Record] box can be clicked to
record the current position estimate in the [Voyage] log. Discrepancy between
LOP result and ship position is also recorded in the log (this information may be
viewed by Info query on the position event symbol on the chart - which is displayed
if position event display is on in chart display settings).
Time transfer : If the observations are not simultaneous, they should be trans-
ferred to a common time. Transferring is based on dead reckoning of ship move-
ment. If a position line (or ring) is transferred, the letters TPL are shown beside its
Manually
entered
position
Enter comment
here.
MAN
1044
Time of
entry
Position event
mark