Less than one year after implementation of a statewide Continuously Operating Reference Stations (CORS) network, New York State Department of Transportation (NYS DOT) is ready to expand its highly successful NYS Spatial Reference Network (NYSNet). Before the end of the year, NYSDOT will have added 10 new CORS to the existing network of 36 stations, thereby providing even greater flexibility, accuracy and opportunity to both public and private field-based survey teams throughout the state.
The Phase-II expansion program included the installation of 10 GRX1200 GG Pro sensors and AT504 GG antennas, located primarily along major transportation corridors where NYS DOT has active, ongoing construction projects. The additional stations help achieve 50-70 km coverage throughout most of the state improving coverage, redundancy and reliability.
The stations automatically measure errors in the GPS satellite signals and compute error correction factors. DGPS and real-time kinematic (RTK) data are streamed instantaneously from the reference stations via internet connections to the Albany facility, where data integrity is checked prior to being streamed to the Internet for public access and redirected to the NGS site in the industry-standard RINEX format. Static raw data files are downloaded every one-half hour.
Currently NYSNet is actively used by NYS DOT Regional survey crews as well as approximately 125 private survey and engineering companies.
Bob LeMoine, Reference Station Support Engineer for Leica Geosystems, concludes, “Network RTK techniques are increasingly valuable to surveyors, particularly for construction and topographic mapping projects located along busy transportation corridors where data can be gathered quickly, easily, and less expensively, thus ensuring the RTK derived project coordinates are all on the same common datum. NYS DOT construction crews frequently use their Leica RTK Rovers and the NYSNet RTK Network for as-built and plan check tasks on active DOT construction projects; working together with construction contracting partners on stake-out and RTK machine control grading/construction projects.”
In 2006, NYS DOT installed 36 CORS sites consisting of Leica GRX1200 Pro dual-frequency, high precision GPS reference sensors and high precision AT504 choke-ring antennas. Once the 10 new stations become operational, the NYS DOT will operate 46 permanent CORS-based stations, each connected to a system of servers and processing software in the NYS DOT facility in Albany. Static and real-time data from the network is available through the Internet. The addition of the 10 new stations to NYSNet provides improved network RTK coverage for users while expanding opportunity for future directions. Each new station and antenna is a GNSS unit (GPS & Glonass) and ready for activation should the need arise.