TM 5-6675-250-20
2-16. DETERMINATION OF AZIMUTH VALUE FOR REFERENCE MIRROR (Continued)
L O C A T I O N / l T EM
A C T I ON
R E M A R KS
S E R V I C E ( C o n t i n u e d)
d.
Place the GRU on the ground so that the
pointer is close to the fixed point and press
leg spades (1) into the ground.
e.
Release hold-down clamps (2) on tripod (3)
and shift GRU in the tripod to position the
pointer over the fixed reference point.
f.
Rotate theodolite alidade (1) to position objec-
tive end of telescope over the NORTH mark
on GRU. Tighten horizontal lock (2).
g.
Preorient GRU (3) to north by
releasing tripod hold-down clamps (4) and
rotate GRU in the tripod until the two
magnetic compass images are in coin-
c i d e n c e.
h.
With telescope level, depress plunger (5) on
magnetic compass (6).
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