11-2
UNHEALTH: Every GPS satellite is broad-
casting abnormal satellite number(s) in the
Almanac. Using this information, the GPS
receiver eliminates any malfunctioning satel-
lite from the GPS satellite schedule. Once the
malfunctioning satellite is returned to on-line
status it is automatically restored to the satel-
lite schedule when the Almanac is received.
In some instances however the Almanac may
not contain information which announces that
a satellite is now back on line. If you hear of
this through another source, you can manu-
ally restore the satellite to the satellite sched-
ule. Conversely, you can manually disable a
healthy satellite if you hear it is unhealthy.
To restore or disable a satellite, select RSTR
or DISABLED on the UNHEALTH line and
then enter satellite number.
TIME DIFF (using local time): GPS uses
UTC time. If you want to use local time, en-
ter time difference between local time and
UTC time here. The key serves to desig-
nate plus or minus time. See the World Time
Standards chart on page A-3 for time differ-
ences.
11.2 Speed Averaging
Calculation of ETA and TTG is based on an
average ship's speed over a given period. If
the period is too long and the ship's speed is
changed suddenly, calculation error will re-
sult. Speed averaging may be increased or
decreased to offset calculation error. The de-
fault setting is 00.
1. Press the MENU key.
2. Press the [0] key.
3. Press the [2] key to display the PLOTTER
SETUP menu.
PLTR SETUP
NAVAID
SCALE
SMOOTHING
SPD AVERAG
BEARING
MAG CALIB
EVNT METHOD
POSITION
DISP
Chain: Sec
LOP CALIB
OWN LC DE ALL
SCALE RANGE
00 (00~15)
00 min
TRUE MAG
AUTO MAN
06.3°W 00.0°E
EVENT MARK
L/L LOP
LC DE
7970: 11-26
+000.0 µs
+000.0 µs
: Cursor ESC: Esc
: E/W, +/-
Figure 11-4 Pltr setup menu
4. Operate the Cursor Pad to select SPD
AVERAG.
5. Enter averaging with numeric keys.
6. Press the ENT and MENU keys to regis-
ter selection.