Atacama Compact Array Antennas

TL;DR

This paper presents comprehensive performance test results of the Atacama Compact Array antennas, demonstrating their high accuracy, stability, and speed, crucial for the ALMA observatory's scientific missions.

Contribution

It provides detailed performance metrics and validation results for the ACA antennas, highlighting their suitability for high-precision astronomical observations.

Findings

Pointing accuracy within 2.0 arcsec

Surface accuracy below 25 micrometers

Path-length stability of 15 micrometers over 3 minutes

Abstract

We report major performance test results of the Atacama Compact Array (ACA) 7-m and 12-m antennas of ALMA (Atacama Large Millimeter/submillimeter Array). The four major performances of the ACA antennas are all-sky pointing (to be not more than 2.0 arcsec), offset pointing (to be < 0.6 arcsec) surface accuracy (< 25(20) micrometer for 12(7)m-antenna), stability of path-length (15 micrometer over 3 min), and high servo capability (6 degrees/s for Azimuth and 3 degrees/s for Elevation). The high performance of the ACA antenna has been extensively evaluated at the Site Erection Facility area at an altitude of about 2900 meters. Test results of pointing performance, surface performance, and fast motion capability are demonstrated.