Updated control system for the portable sub-millimeter telescope (POST)

POST was developed cooperatively by the Purple Mountain Observatory and the National Astronomical Observatory of Japan from 1997 to 2000 [1]. Performance degradation occurred in the POST system after years of operation. So a through upgrade was carried out in 2014, which include hardware and software of the control system, servo system, bias supply power, chopper wheel, weather station, etc. The updated POST telescope system were tested in its' pointing and tracking performance, its far-field beam pattern. The atmosphere opacity and the spectrum lines of standard source (Orion-A and M17SW) observation shows that the system update was a success and the POST could play a significant role in the evaluation of potential sub-millimeter sites based on the radiometric measurements of atmosphere opacity at 500 GHz waveband.