Furuno SC-120 manual Displaying the GPS setup menu, GPS Setup menu description

3. OPERATION

3.7GPS Setup

The GPS SETUP menu smooths position and course, averages speed, applies position offset, and deactivates unhealthy satellites.

3.7.1Displaying the GPS setup menu

1.Press the [MENU] key to open the menu.

2.Choose GPS SETUP and press the [ENT] key.

GPS SETUP

SMOOTH POS	:		0SEC
SMOOTH S/C	:		5SEC
LAT OFFSET	:	0.000’N
LON OFFSET	:	0.000’E
DISABLE SV	:

GPS SETUP menu

3.7.2GPS SETUP menu description

SMOOTH POS (Smoothing position)

When the DOP (Dilution of Precision, the index for position-fixing accuracy) or receiving condition is unfavorable, the GPS fix may change randomly, even if the vessel at anchor. This change can be smoothed by averaging a number of GPS fixes. The setting range is from 0 (no smoothing) to 999 seconds. The setting range is from 0 (no smoothing) to 999 seconds, and the default is 5 s, which is good for rolling period o 5-8 s. The higher the setting the more smoothing. However, too high a setting slows updating of position. “0” is the default setting; increase the setting if the GPS fix fluctuates largely.

SMOOTH S/C (Smoothing speed/course)

Ship’s speed and course are directly measured by receiving GPS satellite signals, independent of positions. The data varies with receiving conditions and other factors. You can reduce this random variation by increasing the smoothing. The higher the setting the more that speed and course are smoothed. If the setting is too high, however, the follow-up to actual values gets slower. The setting range is from 0 (no smoothing) to 999 seconds.

LAT/LON OFFSET (L/L position offset)

If GPS fixes are erroneous while at anchor, enter a position offset to compensate for position error. Consult a nautical chart to determine latitude and longitude differences between the chart and GPS display. Enter that value as the offset.

DISABLE SV (Disable satellite)

Every GPS satellite is broadcasting abnormal satellite number(s) in its Almanac, which contains general orbital data about all GPS satellites. Using this

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