The Pulaski Area Geographic Information System (PAgis) is pleased to provide no-fee, public access to GPS reference station files used for differential correction. PAgis is also providing access to survey grade Real Time Kinematic (RTK) GPS for no-fee to users who wish to register with PAgis.
For survey grade RTK access, fill out the PAgis GPS Reference Station RTK Access Form.
The reference station is a Trimble Alloy GNSS Reference Receiver receiving GPS and GLONASS satellites. The antenna is a Trimble Zephyr 3 Base and is located atop the North Little Rock Electric Administration building in North Little Rock, Arkansas. Use of the reference station is recommended for GPS end users within 300 miles/500km of North Little Rock, Arkansas. The station antenna is positioned at:
1500 W. Maryland Ave.
North Little Rock, AR 72120
Latitude – 34° 50′ 25.87001″ N
Longitude – 92° 15′ 11.47324″ W
Elevation – 148.012 m HAE
Horizontal Datum – NAD83-2011, EPOCH:2002.000
Vertical Datum – NAVD88
Trimble Pathfinder Office will require the base station to be manually added. PAgis has provided a Trimble Base Station Configuration file. If you have any questions follow this link for more information: Trimble User Defined Provider.
DGPS data is collected 24 hours per day, 7 days per week, 365 days per year, in RINEX 2.11 and RINEX 3.04 format. Occasionally, the reference station may be down for upgrades or repairs. Any changes to the DGPS data collection schedule will be announced on the Arkansas GIS Users Forum email listserv. (To subscribe to the listserv go to: https://lists.state.ar.us/mailman/listinfo/gisusersforum )
Recent DGPS data (less than 1 year old) in RINEX 2.11 and RINEX 3.04 compressed file format can be obtained at the following, PAgis maintained, ftp site: ftp://18.104.22.168/recent. Those using Trimble Pathfinder Office software will find “Pulaski Area Geographic Information System (PAgis)” listed as a download site in the “Internet Search” option of the “Differential Correction” module.
All DGPS data is archived for a period of at least 2 years. The archived files can be downloaded directly from the PAgis maintained ftp site at ftp://22.214.171.124/archive.
To access the FTP sites above, use windows explorer or a FTP client such as Filezilla or CoreFTP. Due to security updates to Web Browsers (Chrome, Firefox, and Internet Explorer) will not access FTP sites.
All correction data files are placed on PAgis’s FTP server in one hour increments at approximately 5 minutes after the hour. Each file represents 1 hour of GPS readings with a one-second epoch. The file structure is YYMMDDHH.zip, where YY is the last 2 digits of the year, MM is the month of the year, DD is the day of the month, HH is the hour of the day in GMT (GPS Time) not local time, and .zip is the extension of the compressed files. For more information on GPS versus local time visit http://www.leapsecond.com/java/gpsclock.htm.
The Pulaski Area Geographic Information System (PAgis) hereby disclaims all warranties relating to the GPS reference station information contained on this Internet site whether express or implied, including without limitation any implied warranties related to data integrity, fitness for a particular purpose, or functionality. PAgis will not be liable for any special, incidental, consequential, indirect or similar damages due to the use or misuse of this Internet site and the information contained hereon, even if PAgis has been advised of the possibility of such damages. The person or entity using this Internet site and the information contained on it bears all risk as to the use and application of this information.