Korean VLBI Network (KVN)
Optics and Driving Performance
The KVN antennas are designed to be a shaped-Cassegrain-type antenna
with an altitude-azimuth mount.
The telescope has a 21 m diameter main reflector with a focal length of 6.78 m.
The main reflector consists of 200 aluminum panels with a manufacturing surface accuracy of about 65 micro-meter.
The slewing speed of the main reflector is 3 deg/sec, which enables fast position-switching observations.
The subreflector position, tilt, and tip are remotely controlled and modeled to compensate
for the gravitational deformation of the main reflector and for the sagging-down of the subreflector itself.
The characteristics of the antenna optics are summarized in table below.
|Main Reflector (Axisymmetric Paraboloid
|Panels manufacturing accuracy
|Alignment surface accuracy
|Manufacturing surface accuracy
|Expected total surface accuracy (EL ~ 48 deg)
||AZ:+-270 deg, EL:0-90 deg