The Groupe système Forêt offer a service of reference base station data for post-processing GPS. Located at Québec, the base station produce refence data in SSF f ormat and also in universel format RINEX (Receiver Independant Exchange Format) and this for 24 hours on 24.

Les data is accessible directly thrue this page (just below). An subscription is require to get then password to acces the encrypted data file. The subscription is available by month or year. It is also possible to buy the reference data by week or day.

GPS antenna position from May 1st 2009 : 71º17' 41.5583'' W , 46º 43' 49.5881" N , altitude: 17.884 meters

GPS antenna position BEFORE May 1st 2009 : 71º18' 33.7742'' W , 46º 48' 21.4665" N, altitude: -5.2 meters above ellipsoid and orthométrique elevation : 49.291 meters. MTM 07 coordinates X : 244047.8208, Y : 5177069.479

For more information on the differential GPS data file format, click here ! (june 17, 2009)