NorthStar 957 Operator's Manual page 67

Checking GPS status
Viewing loran
status
Setting loran GRI
957 Operator's Manual, Rev. B
Press the L/L TDS menu key several times to display either the
particular pair of TDs you want to use, or the loran-derived
latitude/longitude.
If you want the 957 to display loran position coordinates from a connected
loran, the loran must support the standard NMEA 0183 "RMA" output data
sentence structure. Without this output capability, the 957 won't receive
position data from the loran.
To display GPS coordinates and signal status, press the CHECK
GPS menu key. The 957 continues to navigate using loran,
and will display loran data the next time you display the
LORAN POSITION screen.
To check the quality of signals being received by your loran,
press the LORAN INFO menu key from the LORAN POSITION
screen. The SNR for each loran transmitting station is
displayed graphically on the LORAN INFO screen.
To change the four-digit loran Group Repetition Interval (GRI),
press the SET GRI menu key on the LORAN POSITION screen.
For the 957 to accurately convert the loran's TDs to latitude/
Chapter 5 - Determining Your Position
NOTE:
Page 59