This array is a polarizing filter, which ensures that
only horizontally polarized energy travels from the
horn region. The antenna scans at a rate of 16 rpm
and produces an absolute gain of 31 dB at midband.
AN/SPN-35A AIRCRAFT CONTROL
APPROACH RADAR
The
AN/SPN-35A
(fig
2-48)
is
a
carrier-controlled-approach (CCA) radar set used for
precision landing approaches during adverse weather
conditions. The radar displays both azimuth and
elevation data, which enables the radar operator to
direct aircraft along a predetermined glide path and
azimuth course line to a transition point approximately
2 miles from the ramp of the flight deck.
The azimuth antenna, AS-1292/TPN-8, functions
in the azimuth rf line for radiation and reception of
X-band rf pulses. The azimuth antenna comprises
a truncated paraboloid-type reflector with an offset
feedhorn and a polarizer assembly that provides
remote-controlled selection of either horizontal or
circular polarization. The antenna is located above
the azimuth drive assembly on the stabilized yoke.
The azimuth drive can rotate the antenna in either 360
degrees or in limited-sector modes of operation in the
horizontal plane.
Figure 2-48.—AN/SPN-3SA aircraft control approach radar.
2-29
