radioastronomy antenna measurement methods
alignment of monopulse channel
equalization of waveguides phase length
The developing and practical phase-in of antenna measurement methods, using achievements of soviet Radio Astronomy science, were generated by emergence of new radar systems for space control and investigations. The appearance and perfection of the required test equipment and science-based methodical instructions conduced to advancement and wide expansion of new methods.
Experiments on the usage of these methods in earth station technique are considered. The application of discrete sources of the extraterrestrial radiation permitted to decide the complicated problem of the adjustment and exploitative control of anglemeter channel parameters of large-size tracking antennas and earth station afterwards.
The so-called antenna «overthrow» method is applied by the alignment of the monopulse channels of tracking antennas. This method comprises in the ability of antenna guidance on the same point of celestial sphere by two manners, that differs from each other on U-turn of the antenna reflector. All measurement errors in such experiment are divided on two classes – with changes and doesn’t changes of their sign by reflector turn. So, an opportunity to eliminate in process of alignment the second class errors appears. These errors are inaccuracy of the phase center location, self-weight deflection, radome effects, refraction, ground reflections etc.
The measurements of the phase difference of monopulse channel transmission lines are also determined by extraterrestrial sources of radio waves radiation.