Figure 4-5.—Collimation tower.
TOWER ARRAY
The tower array can be moved in train and eleva-
tion by either powered or manual means. The array
consists of a metal frame (usually constructed from
aluminum piping) and test antennas and optical tar-
gets required for shore-tower checkout of shipboard
radars. The test antennas and the optical targets are
mounted on the metal frame and spaced to correspond
to the spacing between the center of radiation (RF
axis) and the telescope or boresight axis of each ship-
board radar. This eliminates parallax errors caused by
the small ship-to-tower distance involved during nor-
mal tower operations.
The targets are illuminated by either back lighting
or floodlights. The four test antennas and their charac-
teristics, the associated optical targets, and the appli-
cable radar systems that can be tested are summarized
in figure 4-6.
Figure 4-6.—(A) Standard tower array;
(B) Array usage.
COLLIMATION TEST EQUIPMENT
Each collimation tower is equipped with a set of
test equipment for specific tower use. This equipment
is stowed in the tower equipment room. The major
items include
M. Radar Test Set AN/SPM-9,
4-5
