NorthStar Navigation GM1708 961XD - Manual (Page 69)

SECTION FOUR - Service/Maintenance
961 INSTALLATION MANUAL Revision A Page 59
Figure 30: Receiver information screen
Changing GPS speed averaging value
When you aren’t using DGPS or you’re out of range, you may notice that
the SOG readings obtained from the GPS satellite system are slightly
erratic, varying by up to several knots. The 961’s GPS SPEED AV function
often can improve the steadiness of these readings, although you’ll see a
slightly longer display-reaction time when the speed changes.
With GPS speed averaging, you can select the time over which the 961
averages your speed, with available values between one and ten seconds.
A longer averaging time is useful at lower speeds when you require the
highest accuracy. With this high degree of accuracy, you’ll see a steady
display of your speed that’s slow to change. A shorter averaging time,
however, provides less accuracy and a quicker-changing display of your
speed.
You also can turn off speed averaging completely for the quickest possi-
ble display-reaction time.
NOTE:
If you’re viewing and editing information on the RECEIVER
INFORMATION screen, and you press one of the five func-
tion keys to view other data, the 961 immediately cancels your
edit-in-progress so that you can view the data requested by
your function keypress. To resume editing at the
RECEIVER
INFORMATION screen, you must return to that screen and
re-enter the data you lost when you pressed the function key.
To purposely cancel an edit-in-progress, however, you’d nor-
mally press the
CANCEL key.