Garmin bluechart 182 User Manual

Page of 96
53
Reference
Main Menu:
GPS Tab
works best when there are no nearby obstructions such as buildings, mountains, etc. WAAS satellites 
will be numbered 33 or higher when viewing the sky view on your GPSMAP 182/232. 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 satellites (numbers 32 or below), a ‘D’ will appear in 
the signal bar of the sky view and ‘2D or 3D Differential’ will appear in the receiver status. To learn 
more about the WAAS system, its satellite positions and current state of development, visit the FAA 
web site (http://gps.faa.gov). Since WAAS requires CPU resources of the GPSMAP 182/232 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 GPS tab, press MENU, then use the ARROW KEYPAD to highlight ‘WAAS Off’ or ‘WAAS 
On’ and press ENTER/MARK.
Receiver Status, Accuracy and DOP
Receiver status is indicated at the top fi eld of the page, with the current Accuracy and Dilution Of 
Precision (DOP) to the right of the sky view. DOP is an indication of satellite geometry quality measured 
on a scale of one to ten (lowest numbers the best, highest numbers the poorest). Accuracy uses DOP 
and other factors to calculate horizontal position accuracy in feet or meters. The status fi eld will show 
one of the following conditions:
•    Looking For Satellites— the receiver is looking for any satellites.
•    AutoLocate— the receiver is looking for any satellite whose almanac has been collected. This 
process can take up to fi ve minutes.
•    Acquiring Satellites— the receiver is looking for and collecting data from satellites visible at its last 
known or initialized position, but has not collected enough data to calculate a fi x.
•    2D— at least three satellites with good geometry have been acquired and a 2 dimensional position 
fi x (latitude and longitude) is being calculated. ‘2D Differential’ will appear when you are receiving 
DGPS corrections in 2D mode and a ‘D’ will show on the strength bar of satellites being corrected.
Highlight ‘WAAS Off’ and 
press ENTER/MARK to 
disable the WAAS 
capabilities.
182_232 Manual Part 2.indd
12/21/01, 11:41 AM
53