NorthStar 961x Manual Do Utilizador

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Chapter 14 - Service and Maintenance Functions
961 Operations and Reference Manual Rev. D
Page 14-7
2. Press the CURSOR PAD left or right to select either ON or
OFF
.
3. When done, press the ACCEPT key (or CANCEL to leave
the option unchanged). 
Setting beacon frequency and baud rate
You can set the receiver to operate automatically or be con-
trolled manually. 
Automatic tuning 
Northstar’s two-channel differential receiver enters automatic 
differential mode as soon as corrections are received, and 
doesn’t require any further supervision for differential opera-
tion, automatically tuning to the appropriate differential fre-
quency as you move from one differential coverage area to 
another or as weather conditions change. First, it finds the dif-
ferential frequency and data transfer (baud) rate, then it 
receives data fully automatically. The receiver constantly eval-
uates available radio beacon signals for signal quality, and 
selects only the best station. The receiver is prepared to switch 
to another frequency automatically, as you travel, as condi-
tions require.
The unit maintains automatic operation by using its two inde-
pendent receiver channels: Channel 1 tracks the best available 
differential signal (the one with the lowest data error rate) and 
sends the demodulated DGPS corrections to the 961’s GPS 
receiver. Channel 2
 
continuously
 
scans the entire differential 
frequency band (283.5 to 325 kHz), locating and measuring 
received DGPS differential signals, which is then stored as a 
DGPS differential directory in its battery-powered memory.
If the signal that’s received and monitored by Channel 1 
degrades for any reason, such as bad weather between you 
and the transmitter, the unit tries to select a better frequency 
from the differential directory it has compiled. This feature 
enables it to switch to the best differential signal—before affect-
ing your GPS accuracy.
For normal operation, Northstar recommends that you leave 
both beacon frequency and baud rate at the AUTO setting.