Lowrance GlobalMap 1600, Инструкция по установке и эксплуатации

Страница: 44 / 92

38
Waypoint Averaging
Although electronic position finding devices such as this one show the
position in precise digital numbers, there is some ambiguity in the dis-
played position. With position pinning turned off, you can see this by watch-
ing the position displayed on the unit move while you’re standing still. This
is due to many factors; SA, atmospheric conditions, the number of satel-
lites being tracked and their location relative to your position, and so on.
However, even with SA turned on, this GPS receiver can show surpris-
ingly accurate position information. If you wish to increase the accuracy
of a saved position, use the waypoint averaging method. This method
requires the unit to remain untouched at the location that you want to
save, preferably for at least one hour. Longer times will result in a better
position. The unit averages all of the positions reported by its GPS re-
ceiver, resulting in typically higher position accuracy.
To use this feature, first press the WPT key and
select a waypoint number, then select “CREATE
WAYPOINT”. The screen in the middle of the pre-
vious page appears. Now select “AVERAGE
POSITION”. The screen shown at right appears.
Your present position shows at the top of the
screen. A box with a plotter graphically shows
the movement of your average position. The num-
ber of positions or points taken appears next to
the plotter. The position is updated once per second. Now place the unit
where it has an unobstructed view of the sky. At the end of the position
gathering time, press the ENT key to save the averaged position.
Project Position
You can save a waypoint even if you don’t know it’s position or location on
the map. This unit lets you project the location of a waypoint from a known
waypoint using only bearing and distance from the known waypoint. This
is useful if you don’t know the latitude/longitude of a location, but you do
know the distance and bearing from a saved waypoint or your own posi-
tion.
(Note: To project a waypoint from your present
position, you must first save your present posi-
tion as a waypoint.)
To use this feature, press the WPT key, then se-
lect a waypoint number that you want to save the
projected waypoint under. Waypoint 7 is used in