NorthStar 961 Install Manual page 43

SECTION TWO - Installation
current positions, not on actual received signals, and doesn't consider
atmospheric conditions or signal interference, which both affect accuracy.
HDOP can range from an ideal value of slightly less than one, up to a
poor value of 10 or more. Any value less than two indicates excellent
performance.
Lat/lon coordinates
On the CHART screen INFO BARS, the 961/962 displays lat/lon as degrees,
minutes, and thousandths of minutes. To display this data, press the
key several times. After press the first key, a second key is
displayed, which lets you display additional data on a second INFO BAR.
SOG and COG
You can display SOG and COG in the INFO BAR on the CHART screen,
and on the 3-D STEER screen or numeric STEER screen. To display SOG
and COG on either the STEER or 3-D STEER screens, press the
key
once or twice.
SOG and COG readings result from ongoing measurements derived from
the satellite signals. SOG speed is updated every second. You can set the
961/962 to display its SOG and COG readings more smoothly by setting
the GPS speed averaging value at up to 10 seconds. Increasing this
averaging time, however, may reduce overall reaction time. For more
details about setting GPS speed averaging value, see Chapter 14 in the
Northstar 961/962 Operations and Reference Manual (part number
GM1900).
Loran-C TDs
The 961/962 also calculates Loran-C TDs from the GPS coordinates, and
displays them on the CHART-screen INFO BARs. For more details, see
"Viewing loran TDs" in Chapter 5 of the Northstar 961/962 Operations
and Reference Manual (part number GM1900).
If you don't touch any key on the control head for one hour or more, its
About
LCD screen automatically dims to about half its maximum brightness
auto-dimming
(based on its current brightness), if required by the system. Pressing any
mode
key at any time automatically restores the display's previous brightness
level. The auto-dimming function helps maintain the integrity of the
display screen and reduce power consumption when the 961/962 is on
for many hours. It is still recommended, however, that you keep the
lighting level lower when you don't actually need it.
961/962 INSTALLATION MANUAL Revision A Page 33