Reference Station

In Norway, 2.5km down the valley in the Melkevol reception/cafe a PC was connected to the internet.

The cafe in Norway

Kirk attaching the GPS antenna









It used a small low power PC (mini-ITX) running Linux, with a radio modem running PPP so the base could connect whenever it wanted to send files. It backed up everything on disk and sent daily data to Southampton each night – initially over an ISDN dial-up, then over broadband. Originally it had a dGPS on the roof as well. It also had a backup weather station. An “ssh tunnel” allowed us to login to the PC any morning and hence connect up to the glacier when the base station was awake.

In Iceland the GPS reference/fixed station was installed on a cafe on the mountain, only 1km away from the base station (closer means more accurate GPS).

The cafe in Iceland

Although the building has power in the summer – it is turned off in September – so it has to then survive on battery/10W solar power. It uses the same low power technique as the base station. In order to take GPS recordings in sync with the base it sends/fetches power states from a server in Southampton.