ARMY TM 9-6675-349-12&P
MARINE CORPS TM 11039A-12&P
3-24. Theodolite Measurements Continued
d. Offset Distance Measurement.
NOTE
At night, illuminate porro prism scale with flashlight. Porro prism has two scales
for inverting and non-inverting instruments.
(1) If distance between porro prism scale and theodolite is less than 12 meters, locate left vertical stadia
line on porro prism scale zero mark. Read the scale where the right stadia line intersects the scale.
Example: Stadia lines on 0 and 3.8 on scale. Offset distance is 3.8 meters.
RIGHT
LEFT STADIA
STADIA LINE
LINE
0
1
2
3
4
(2) For distances greater than 12 m (right stadia line will fall off the stadia scale) read the center vertical
crosshair and multiply by two to obtain the distance between 12 m and 24 m.
LEFT STADIA
CENTER VERTICAL
LINE
CROSSHAIR
0
1
2
3
6
7
8
4
5
3-25. Marking Position, Azimuth, and Altitude Using Theodolite.
NOTE
IPADS will not adjust azimuths obtained in position, azimuth, and altitude
marks using a theodolite.
IPADS can establish two OLs for an OS using a theodolite.
a.
Stop vehicle close to point to be established.
b.
Exit vehicle and initiate a ZUPT, paragraph 3-14, table 3-4.
c.
Set up theodolite over OS marker to be established and achieve auto-reflection, paragraph 3-24a.
d.
If a short OL will be established, set up range pole over EOL marker.
e.
Vehicle operator becomes the recorder for IPADS operator.
f.
Measure and record offset distance, vertical angle and mean horizontal angle, paragraph 3-24,
subparagraphs b, c, and d. If applicable, measure and record mean horizontal angle for second OL.
g.
From MENU, MAP, or NAVIGATION AID page, press F2. MARK page will be displayed with function
key legend showing F1-2POS, F2-1POS, F3- AZ, F4- SCP, and F9-EXIT.
3-60
