Base Files

Toolik Field Station maintains a continuous GPS base station for use by the Toolik community and the general public. The base station runs continuously year-round (since May 2006), with files permanently archived and available for download through this Web site (links below). Please see the Equipment Page for detailed descriptions of the base station components as well as GPS rover units available for use at the station.

From May 2001 - August 2003 the base receiver was a Trimble ProXR (mapping grade), supporting code (RTK and post-processed) and carrier phase (post-processed) corrections. Under optimal circumstances, code corrected data can deliver accuracy to within several meters, and carrier corrected data can deliver sub-meter accuracy. Toolik Field Station was closed from September to April during these years, and archived data from this period cover only the summer months.
In May 2004 the Toolik Field Station GPS Base was upgraded to a Trimble 5700 (survey grade), which supports survey and mapping grade corrections (RTK and post-processed). In April 2005, the base was upgraded to a Trimble NetRS (survey grade) which supports mapping and survey grade corrections (post-processed and RTK), and is configured through a web interface.
In May 2011, the Toolik Field Station GPS base station receiver was upgraded to a survey-grade Trimble NetR8 receiver. Our new NetR8 receiver offers the following improvements over our previous receiver: tracking GLONASS GPS satellites, faster operation speed, and increased onboard memory storage. Our NetR8 still supports mapping and survey grade corrections (post-processed and RTK). Since April 2006 Toolik Field Station has been in year-round operation, and our GPS archive contains an almost unbroken data string since that time




TFS Base Coordinate (from NGS OPUS Solution - Summer 2012, 7 day average, 30 sec. obs.)

WGS84 – ITRF (EPOCH: 1997) a.k.a (G1150)
Latitude & Longitude Elevation
DD: 68.627536150°N, 149.597754960°W No Geoid Model: 739.958m
DMS: 68° 37' 39.13014"N, 149° 35' 51.917856"W Geoid AK12: 735.268m
WGS84 - IGS08 (Epoch:2012)
Latitude & Longitude Elevation
DD: 668.627533275°N, 149.597759041°W No Geoid Model: 739.984m
DMS: 668° 37' 39.11979"N, 149° 35' 51.932548"W  
NAD83 (2011) (Epoch:2010)
Latitude & Longitude Elevation
DD: 68.627534920°N, 149.597724608°W No Geoid Model: 739.518m
DMS: 68° 37' 39.125712"N, 149° 35' 51.808589"W Geoid AK12: 735.268m