NorthStar 961, Reference Manual

Page: 281 / 404

Chapter 13 - Customizing Setup Functions
961/962 Operations and Reference Manual, Rev. A Page 13-11
At the
NAVIGATION SETUP
screen, you can view or edit any of
the following options:
• geodetic datum
• preferred loran GRI
• waypoint switching
• magnetic variation
• distance, bearing, and steering calculations
Each of these options is described in detail below.
NOTE:
If you’re viewing and editing information on the
NAVIGATION
SETUP
screen, and you press one of the five function keys to view
other data, your edit-in-progress is immediately cancelled so you
can view the data requested by your function keypress. To resume
editing at the
NAVIGATION SETUP
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 normally press the
CANCEL
key.
Geodetic
datum
Different regions of the world have various models for lat/lon
coordinates on their charts; each model is called a datum. The
datum used on the
CHART
screen always matches that of the
chart-in-use. The non-chart screens and the serial data input
and output use the same datum as chart view A, unless you
change the
GEO DATUM
setting from auto to manual. Once in
manual, you then select the datum you want to use for
non-chart screens and serial data. Note that when you set
geodetic datum to manual, the same physical location, such as
a waypoint, may have slightly different coordinates on the
CHART
screen and non-chart screens.
All referenced datums are listed, according to Defense
Mapping Agency publications, in the geodetic datum option.
To change the non-chart screen datum reference:
1. At the
NAVIGATION SETUP
screen, press the
CURSOR
PAD
to highlight the
GEO DATUM
option, then press the
EDIT
key.
2. Press the
CURSOR PAD
right or press the
ARROW
keys
to select
MAN
(for manual), then press the
ACCEPT
key.