Garmin GPSMAP 238 Sounder - Manual (Page 78)

68
Reference
Main Menu: GPS Tab
• Pages – enables main pages to be shut off, turned on, or ‘jumped to’.
• Map – sets up Map Page features, zooms, and text size. See pages 29-32.
• Temp – sets up and shows the water temperature log.
• Hiway – sets up Highway Page features. See pages 42-43.
• Sonar – sets up Sonar Page features, speeds and calibrations. See pages 38-40.
• Systm – defi nes beeper and simulator, restores setup, and displays software version.
• Units – defi nes position format, datum, heading, and distance and speed units.
• Comm – interface settings for use with a PC or second device.
• Alarm – sets up alarms for anchor drag, arrival, off course, and clock.
GPS Tab— provides a visual reference of satellite acquisition, receiver status, and accuracy. The status
information will give you an idea of what the receiver is doing at any given moment. The sky view and
signal strength bars give you an indication of what satellites are visible to the receiver and whether or
not they are being tracked. The signal strength is shown on a bar graph for each satellite, with the satel-
lite number below. As the receiver locks onto satellites, a signal strength bar appears for each satellite in
view. The progress of satellite acquisition is shown in three stages:
• No signal strength bars— the receiver is looking for the satellites indicated.
• Light/White signal strength bars— the receiver has found the satellite(s) and is collecting data.
• Dark/Green signal strength bars— the receiver has collected the necessary data and the satellite(s)
are ready for use.
As soon as the GPSMAP 188/188C/238 Sounder has collected the necessary data from the best
satellites in view to calculate a fi x, the status fi eld will indicate a 2D or 3D status. The unit will then
update the position, date and time.
You can use the sky view to help determine if any satellites are being blocked, and whether you
have a current position fi x (indicated by a ‘2D’,‘2D Differential’,‘3D’, or ‘3D Differential’ in the status
fi eld). The sky view shows a bird’s-eye view of the position of each satellite relative to the receiver’s
last known position. The outer circle represents the horizon (north up), the inner circle 45º above the
horizon, and the center point a position directly overhead. You can also set the sky view to a ‘Track Up’
confi guration, causing the top of the sky view to align along your current track heading.
Sky View
Signal
Strength
Bars
Receiver
Status
Differential
Status
Accuracy
DOP
45°
90°
Outer ring
the horizon
Inner ring- 45°
above the horizon
Center dot - 90°
above the horizon
Main Menu— GPS Tab
188188C238 Manual Part 2.indd 68 6/30/2003, 3:32:18 PM