Welcome to the City of Madison, Wisconsin
GPS Community Base Station

The information provided here is subject to change without notice. Please check this page periodically for updated information.

March 2013 - The Wisconsin Department of Transportation has determined the reference position for the new base at Emil Street which is being used in the WISCORS (VRS) network as station MAON. Correction data from the new base, in DAT and RINEX formats, is now available for downloading and real-time use.

If you have any questions, please contact -
Eric Pederson (608)266-4056 or Dan Rodman (608) 266-6674

Click to see the reference position for the NEW Trimble NetR5 base station

The City of Madison provides real-time correction data files for download over the internet. Data is only available from the city's new Trimble NetR5 base station at Emil Street -

Correction data files from the NEW base station at Emil Street are available in the following formats and time slices:
Hourly files Daily files Time used in the correction files is based on UTC. Hourly files are generally available 5 minutes past the top of each hour. Daily files are generally available 5 minutes past midnight UTC (GMT). The hourly correction files are retained for 30 days and the daily correction files are retained for 180 days. After those time periods, the files are deleted from the web server. The files are not archived.
Check the current UTC time.
DAT_2 DAT_2
RINEX_2 and
Ephemeris
RINEX_2 and
Ephemeris

Users of Trimble's PathFinder Office can view PDF files containing instructions for using the correction data files from the NEW base station for post-processing:
Click here to view a PDF file (1.2 MB) with instructions and screen shots from the PathFinder Office Differential Correction Wizard.

Correction data is broadcast at 460.425 MHz in RTCM + RTK (version 3.0) formats, at 9,600 baud, from the City's communications tower at Larkin Park on the near west side of Madison. The correction data is broadcast using a Trimble TrimMark 3 radio feeding a 100 watt booster amplifier. The effective signal strength from the transmitting antenna is somewhat less than 100 watts.

The City of Madison has established 10 high-order control points located throughout the city. These points are in the process of being "Blue Booked" by the NGS. The City has received tentative positions for these control points. Click here to view the latest information about these control points.

These GPS correction data files are provided as is, with no warranty, either expressed or implied. It is your responsibility to use these files properly. The City of Madison assumes no liability for the accuracy, or subsequent use, of these files. By downloading files you agree to these terms and conditions.

Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement or recommendation by the City of Madison.

Additional information regarding the establishment and verification of the OLD base station position
Base station status announcements
GPS Control Points