Garmin GPS 152 - Manual (Page 74)

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45°
90°
Outer ring -
the horizon
Inner ring- 45°
above the horizon
Center dot - 90°
above the horizon
Main Menu:
GPS Tab
Reference GPS Tab — Provides a visual reference of satellite acquisition, accuracy, and receiver status. 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 indicate 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 satellite number
below. As the receiver locks onto satellites, a signal strength bar will appear for each satellite in view,
with the appropriate satellite number underneath each bar. The progress of satellite acquisition is
shown in three stages:
• No signal strength bars — The receiver is looking for the satellites indicated.
• Light signal strength bars — The receiver has found the satellite(s) and is collecting data.
• Dark signal strength bars — The receiver has collected the necessary data and is ready for use.
As soon as the GPS 152 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 Navigation’, ‘2D Diff Navigation’,‘3D Navigation’, or
’3D Diff Navigation’ 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 (see fi gure
to the left). 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.
WAAS Capability
The GPS 152 is capable of receiving WAAS (Wide Area Augmentation System) satellite signals.
WAAS is an FAA (Federal Aviation Administration) funded project to improve the overall accuracy and
integrity of the GPS signal for aviation use, but land/sea based users may also benefi t from this system.
At this time the system is still in the development stage and is not fully operational. There are currently
two WAAS satellites that can be received in the U.S.A., one over the Atlantic Ocean and one over the
Pacifi c Ocean, in a geo-stationary orbit over the equator. Effective use of the WAAS satellite signal may
be limited by your geographic location in relation to those satellites, now in developmental service.
GPS tab Sky View Signal Strength
Bars
152 Manual Part 2.indd 64 11/27/2002, 2:56:42 PM