The Zugspitze GPS system consists of a RegAnt-1 Choke Ring Antenna and a Legacy-H GD L1+L2 receiver (Topcon/Allsat Inc., Germany). The second system, installed at Garmisch, was provided by our partners at Geoforschungszentrum Potsdam, Germany and consists of a Ashtech Choke Ring Antenna and a TurboRogue SNR-800 receiver. A GPS receiver raw data file (sample rate 30 seconds) is stored and automatically transferred via ftp every full hour. Retrieval of water vapor vertical columns is performed automatically at Geoforschungszentrum Potsdam and provided back as a file containing the two half hourly means of each hour with a delay of 45 minutes after the full hour:
The Figure shows water vapor total column half hourly mean values as a function of time (UTC) from the Garmisch GPS ("ifu1") and the Zugspitze GPS ("zugs"), respectively.