A tolerance study of the 18 m offset Gregorian dual reflector antenna for the ngVLA

The National Radio Astronomy Observatory (NRAO) is planning to build a new radio astronomical instrument, called the Next Generation Very Large Array (ngVLA). The core will be built at the existing VLA site in New Mexico, USA. The reference design [1] for this instrument specifies offset Gregorian dual reflector antennas of which approximately 244 antennas will have an 18 meter aperture diameter and 19 antennas a 6 meter aperture diameter. This work will focus on the 18 meter reflector system.