TM 1-1520-240-MTF
4-61
w. Set Data switch to POS and manually
record present position coordinates.
x. Set Data switch to DIS-TG and manually
record distance to Cp-2 (line two).
y. Return to ground station.
11. GPS/Doppler Flight Test Data Analysis
Compare all MARK positions with the actual
positions of the corresponding Check Point.
Compare differences, if any, with Allowable Nav-
igation
Error
Limits
outlines
in
TM
11-5826-308-12. If errors exceed the Allowable
Navigation Error Limits, use the self-test of the
GPS system and fault isolation procedures to
determine the failure mode.
12. Zeroize loaded keys from GPS memory.
NOTE
Zeroize at termination of test flight or so dic-
tated by operations.
NOTE
Aircraft power must be connected, or power
applied to aircraft.
a. Lift zeroize switch guard and toggle switch.
b. With the GPS receiver turned on, turn Data
Switch to Stat. Observe message on Page
1, Line 2. The message ZEROED indicates
all keys have been erased from memory and
the unit is unclassified.
O AN/ASN-128B DOPPLER WITH EMBEDDED GPS
13. DGNS Flight Test Procedure.
a. Verify proper system operation with MODE
switch to TEST. Left display GO and Right
display ALL. MAL lamp is off.
