Figure 60. Theodolite ML474/GM.
larly adaptable for balloon observation work. The
1. NOMENCLATURE: Theodolite, Double-Center ML
ML474/GM is used to follow the movement of a pilot
balloon while it is being carried horizontally through the
2. TYPE CLASSIFICATION: Standard A.
atmosphere by the airflow. Readings of the elevation and
the azimuth of the balloon are made at regular intervals
3. SECURITY REQUIREMENTS: Unclassified.
to determine the speed and direction of the winds aloft at
4. PRIMARY USE OR CONCEPT OF EMPLOYMENT:
Used for the observation of meteorological balloons.
6. TECHNICAL CHARACTERISTICS:
5. BRIEF FUNCTIONAL DESCRIPTION:
_ _ _ _ _ _ _ Right angle, with
Theodolite, Double-Center ML474/GM is a portable,
right-angle, telescope-type surveying instrument particu-