Furuno GP-1850WDF, GP-1850WF manual 11-6, Geodetic datum window

11. CUSTOMIZING YOUR UNIT

1.Select GEODETIC DATUM.

2.Press the EDIT soft key to show the geodetic datum window.

GEODETIC DATUM

▲

AUSTRALIA

▼

CHART DATUM

WGS-84

Geodetic datum window

3.Press ▲ or ▼ to select the chart system you are using. If UNKNOWN appears in the GEODETIC DATUM window, select a different chart system to show the proper chart datum.

4.Press the ENTER soft key or the [ENTER] key to register your selection.

POS SMOOTHING

When the DOP or receiving condition is unfavorable, the GPS fix may change, even if the vessel is dead in water. This change can be reduced by smoothing the raw GPS fixes. A setting between 000 to 999 is available. The higher the setting, the more smoothed the raw data, however too high a setting slows response time to change in latitude and longitude. This is especially noticeable at high ship’s speeds. 000 is the normal setting; increase the setting if the GPS fix changes.

SPD/CSE SMOOTHING

During position fixing, ship’s velocity (speed and course) is directly measured by receiving GPS satellite signals. The raw velocity data may change randomly depending on receiving conditions and other factors. You can reduce this random variation by increasing the smoothing. Like with latitude and longitude smoothing, the higher the speed and course smoothing the more smoothed the raw data. If the setting is too high, however, the response to speed and course change slows. For no smoothing,

enter all zeroes. The default setting is 005 (sec).

GPS SPEED AVE

Calculation of ETA is based on average ship’s speed over a given period. If the period is too long or too short calculation error will result. Change this setting if calculation error occurs. The default setting is 60 seconds, which is suitable for most conditions.

LAT OFFSET, LON OFFSET

GPS-generated position may be off from the chart. In this case, you can apply an offset to GPS position to refine position accuracy.

Mark the equipment indication on the chart, and then calculate the L/L error.

1.Select LAT OFFSET or LON OFFSET.

2.Press the EDIT soft key.

3.Key in the error value. To switch the north and south (east and west), press the N<->S (W<->E) soft key.

4.Press the ENTER soft key or [ENTER] key.

DISABLE SATELLITE

Every GPS satellite is broadcasting abnormal satellite number(s) in its Almanac, which contains general orbital data about all GPS satellites, including those which are malfunctioning. Using this information, the GPS receiver automatically eliminates any malfunctioning satellite from the GPS satellite schedule. However, the Almanac sometimes may not contain this information. If you hear about a malfunctioning satellite from another source, you can disable it manually. Enter satellite number (max. 3 satellites) in two digits and press the ENTER soft key or the [ENTER] key.

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