Appendix C - What Is Waas - Garmin eTrex Summit - Hiking GPS Receiver Owner's Manual

Appendix C
What is WAAS?
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WAAS Capability
The eTrex Summit is capable of receiving WAAS (Wide Area Augmentation System) satel-
lite 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. 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. WAAS satellite signal reception requires an absolute
clear view of the sky and works best when there are no nearby obstructions such as buildings
or mountains. WAAS satellites are numbered 33 or higher when viewing the sky view on
your eTrex Summit. Initial reception of the WAAS signal may take up to 15-20 minutes, then
1-2 minutes afterwards. When WAAS differential correction has been received for GPS satel-
lites (numbers 32 or below), a 'D' appears in the signal bar of the Advanced Sky View. When
enough satellites have received WAAS differential correction, 'DIFF' appears below the 'Ready
to Navigate' message. To learn more about the WAAS system, its satellite positions and cur-
rent state of development, visit the FAA Web site ( http://gps.faa.gov ). Since WAAS requires
CPU resources of the eTrex Summit to search for and track the satellites, you may disable the
WAAS feature to improve unit performance if WAAS reception is not available in your area.
To disable/enable WAAS capability:
1. From the MENU Page, highlight 'SETUP' and press ENTER. The SETUP Page appears.
2. Press the UP or DOWN button to highlight 'SYSTEM'. Press ENTER. The SYSTEM Page
appears.
3. Press the UP or DOWN button to highlight 'GPS'. Press ENTER. The Option List appears.
4. Press the UP or DOWN button to highlight 'WAAS' mode and press ENTER.