To change the unit of measure:
1. Highlight the ‘units’ field, and press
F
.
2. Select the desired unit of measure, and press
F
.
Speed Filter
The speed filter allows you to determine how the
GPS 126/128 responds to changes in track or ground
speed. Three settings are available: automatic, on, or
off. The ‘Auto’ setting is the default and will monitor
changes in your current track and speed and adjust the
receiver’s response time automatically. The ‘On’ setting
allows you to manually enter a response time up to
300 seconds. Selecting a higher setting may be desir-
able in slow-speed applications with frequent changes
in track.
To enter a value for the speed filter:
1. Highlight the ‘SPEED FILTER’ field and press
F
.
2. Select the ‘ON’ option and press
F
.
3. Highlight the “speed value” field and press the
F
key.
4. Use
U
and
D
to select the desired number of
seconds.
5. Press the
F
key to confirm the selection.
Magnetic Heading Reference
The GPS 126/128’s heading information can be dis-
played referencing magnetic north (automatic or user-
defined), true north, or calculated grid headings. The
default setting is automatic magnetic north, which is
suitable for most applications.
To select a heading reference:
1. Highlight the ‘heading’ field, and press
F
.
2. Select the desired heading preference, and press
F
.
To enter a user-defined magnetic heading:
.
1. Select ‘User Mag’ and press
F
.
2. Press
F
, enter the degrees and direction of mag-
netic variation, then press
F
.
49
REFERENCE
Speed Filter and
Magnetic
Heading
To enter a user-defined
magnetic variation, select
the ‘User Mag’ option and
enter the desired direction
and value.
The number entered repre-
sents a window of time the
GPS 126/128 considers in
adjusting to changes in
speed and track. For exam-
ple, if 12 seconds is entered,
the speed displayed will
constantly represent the
speed averaged over the last
12 seconds.
126/128 Manual (new) 6/15/98 9:51 AM Page 49