961/962 Operations and Reference Manual, Rev. A
There are three bar graphs that display:
•
SNR
•
SIGNAL
•
NOISE
SNR is a good measure of overall signal quality, and should be
as high as possible. Values of 15 and higher are preferable;
anything below 10 could indicate poor reception.
SIGNAL is the actual strength of the received signal, and
should be as high as possible. Signal strength varies with the
distance from the differential transmitter.
NOISE is the level of static caused by lightning and other
atmospheric effects, and should be low for best results. The
range of noise-level meanings are outlined in "Table 2:
Noise-level meanings" below.
Table 2: Noise-level meanings
Noise-level value
200 and less
1,000–3,000
5,000–10,000
For information on optimizing these numbers, see the
Northstar 961/962 GPS Chart Navigator Installation Manual.
Chapter 5 - Understanding Position Coordinates
Meaning
excellent
typical at night
thunderstorm
Page 5-5