CHAPTER 4
COLLIMATION
LEARNING OBJECTIVES
Upon completing this chapter, you should be able to do the
following:
1. Describe the theory of radar collimation.
2. Describe the requirements for radar collimation of the Tartar/SM1
missile fire-control system.
3. Identify the basic equipment used during radar collimation with a shore
tower.
INTRODUCTION
Radar collimation is the parallel alignment of the
radar beam axis and the optical axis of the radar an-
The collimation of fire-control radars is one of the
tenna. It can be accomplished by using either a shore-
major steps toward achieving a successful battery
alignment. This chapter discusses the theory of radar
collimation, collimation requirements, shore tower-
based operation and requirements, and test equipment
and procedures used in collimation and correlation,
especially as applied to the Tartar (Standard) Guided-
Missile, Fire-Control System (GMFCS). Keep in
mind that although the specific equipment used on
board your ship may be differ from the example used
in this chapter, the purpose is still the same; that is, to
achieve a successful battery alignment.
RADAR COLLIMATION THEORY
Collimation is an optical electronic technique used
to establish parallelism between the radio-frequency
(RF) beams radiated from a radar antenna or between
the RF beam and the optical line-of-sight (LOS) axis
of the antenna. This optical axis is called the boresight
axis and is established with the optical telescope.
based tower or a portable ship’s tower that supports
both an optical target and a radar horn antenna.
The horn antenna is connected to the RF power-
measuring equipment and is properly positioned in
relation to the optical target. The horn antenna dis-
placement, relative to the optical target, is determined
by the relative displacement of the two axes (optical
and RF), as measured at the radar.
The parallelism of the two axes is checked or
adjusted by training and elevating the radar antenna
until the cross hairs of the optical sight intersect the
optical target. At that time, maximum RF energy
should be directed into the horn antenna, as measured
by the power-measuring equipment. If it is not, the
axes will not be collimated, and appropriate adjust-
ment procedures must be accomplished, as one axis
must be aligned to the other axis until they are paral-
lel.
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