Garmin GPS 152 Owner's Manual - Page 74

Reference Main Menu: GPS Tab 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. Sky View GPS tab Signal Strength Bars Center dot - 90° 90° above the horizon Inner ring- 45° above the horizon As soon as the GPS 152 has collected the necessary data from the best satellites in view to calculate a fix, the status field 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 fix (indicated by a '2D Navigation', '2D Diff Navigation','3D Navigation', or '3D Diff Navigation' in the status field). 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 figure to the left). You can also set the sky view to a 'Track Up' configuration, causing the top of the sky view to align along your current track heading. 45° 64 Outer ring the horizon 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 benefit 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 Pacific 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.