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About the WSRN
The WSRN (Washington State Reference Network) is a regional cooperative of GPS reference stations and data that enables cost-saving solutions for public and private sectors in the fields of surveying, mapping, science, precision agriculture, construction, and other high accuracy positioning technology needs
The WSRN is operated as a cooperative of 80+ cities, counties, utilities, state agencies, and private entities (infrastructure partners) who maintain, operate, or otherwise contribute to the operation of a statewide array of over 100 Continuously Operating Reference Stations (CORS). These GPS/GNSS CORS provide raw GNSS observation data for both real-time and static high precision positioning. Static data is free to the public, with real-time services available for authorized infrastructure partners, and for non-infrastructure partners (users who contribute annual fees to defray operational costs)
Real-Time Networks (RTN) - A Timely Solution
There are over 400 Real-Time Networks (RTN) like the WSRN worldwide where some networks span entire countries. Utilization is spreading beyond surveying to mapping to utilities, emergency response, agriculture, forestry, public safety, transportation, machine control for construction, environmental, and scientific research. Cost savings can be substantial. High accuracies at high speed: By following proper procedures, users can observe locations to centimeters in seconds
The Role of Seattle Public Utilities
Seattle Public Utilities (SPU) serves as the central data processing host for the VRS network, and maintains key elements of a core network for internal SPU and city needs. The core network includes three SPU stations, and seven stations hosted by surrounding entities through signed agreements with SPU. The network is scalable and through the efforts of partners has expanded across the state, this has included SPU and SCL operations in the Skagit and Boundary regions
The Central Processing Centers (CPC)
The CPC's provide central communications, data processing, correction distribution, integrity monitoring, support, GPS/GNSS data file access, real-time and web-based services for WSRN members and subscribers. Many of the WSRN services are free and open to the public, with the exception of real-time network corrections, which is accessed by authenticated access accounts. The primary CPC is in Seattle, with a mirror site operated by Central Washington University in Ellensburg
Conceptual Model of the WSRN
The WSRN is comprised of a network of regional CORS (Continuously Operating Reference Stations connected via the Internet to a Central Processing Center (hosted by SPU). These CORS are essentially a high-end GPS receiver with a geodetic-grade antenna on a very stable mount. The CORS dual-frequency receivers can be from any number of manufacturers; there are already Trimble, Topcon, Geotracer, and Leica receivers, the choice of each CORS host. These CORS are at physically secure locations with reliable sources of power and Internet communications. These stations are typically located at 30-70km intervals but can maintain effectiveness even if spaced up to 100km apart. The WSRN provides “correction” products per RTCM and industry standards in multiple “network correction” formats as well as multiple “single-base” formats for each station. These stations transmit streams of GPS/GNSS observations, from multiple satellites and satellite constellations, simultaneously to the CPC. Users of the services may utilize static GPS data files from the CPC via Internet or enhanced GPS/GNSS data corrections in real-time
The Role of Central Washington University (CWU)
The Geodesy Lab of CWU has operated GPS sensors for plate tectonic studies for several deacades and utilizes data from over 300 CORS in the Pacific Northwest, including all 100+ WSRN CORS. CWU has been a fundamental partner in the WSRN since it's conception, providing infrastructure and expertise in development of nearly all WSRN CORS. CWU also operates the redundant servers for the WSRN
Static Files
The CPC also generates the static GPS files (at 1Hz; 1 second epoch; and by custom orders) and posts these to the WSRN web server, transmits specific data to scientific and academic research concerns via FTP, processes requests for custom time-period & rate static files, and can generate a 'Virtual' static file which also includes atmospheric and orbital modeling. The user may download static GPS data files for 'post-processing' along with their own field observation files to derived accurate locations. These static files are freely available to all via the Reference Data Shop where custom orders can be placed for processing and download. The end-user is responsible for their own post-processing. These static files are available in standard RTCM formats plus a few other industry formats. Files are available for custom orders for 30 days, with older files archived on the CWU FTP site at: ftp.panga.cwu.edu/incoming/
Real-Time Services
The CPC provides a central portal for users to access traditional Real-Time Kinematic GPS corrections from individual CORS, or the more enhanced “network” type of correction from multiple stations simultaneously. Access is via registered password protected accounts.The user initiates a session from their own mobile field GPS/GNSS unit (rover) by contacting the CPC via cellular (or other internet) data connection and chooses the style of correction desired. Network corrections can help offset certain types sources of error common to real-time GPS, like the atmospheric delays. In the case of a “virtual base” observation, the rover sends it's autonomous (rough) location to the CPC. The CPC then develops an atmospheric model from (up to) the nearest six CORS, and adds corrected orbital info (from federal sources on the web), develops a unique set of corrections for the users location then sends a corrected stream back to the rover
The WSRN can also offer other network correction styles like MAC (master-auxiliary) and FKP. These corrections are in industry standard formats of several types RTCM and CMR(+), useable by rovers produced by multiple manufacturers, and as the CPC software is on a maintenance/subscription model, newer industry standards will be implemented as they are approved by the international RTCM committee. The NTRIP authentication protocol for secure access accounts is also an industry standard, implemented by most manufacturers, and more as has happened in worldwide
WSRN Development Timeline
1. - Regional entities implement conventional GPS for surveying and mapping in the late 80's and early 1990's
2. - GPS is utilized to establish base themes for the City of Seattle GIS - Joint Aerial Mapping Project 1993
3. - First regional reference stations are independently established by individual entities, like the city of Renton in the mid to late 90's. First SPU reference station established in conjunction with UW Geophysics and PANGA in 1999
4. - Meeting of interested parties proposes Northwest Unified Base Station (NUBS) network in 1998
5. - WSRN conceptually formed by Dave Riecken of Metro-King County, Bob Maconie of the city of Renton and Gavin Schrock of SPU in 2000
6. - Pilot Virtual Reference Station network (4 stations) established in cooperation with City of Renton and Kitsap PUD - Nov 2002. 2 King County stations added in early 2003
7. - Pierce County CORS goes online in mid 2003, with real-time and web services
8. - SPU approval of production network (10 stations) and funding - May 2004
9. - Core network launched (8 of 10 stations) - Aug 2004, members and partners begin use
10. - Core network completed Dec 2004 - 10 Stations. The WSRN commits to constraining all network CORS to the national spatial reference framework maintained by the National Geodetic Survey – NAD83-CORS96 Epoch 2002.00
11. - Expanded network begins - 15 stations by April 2005, test period ends, first subscribers
12. - Development plan in conjunction with PANGA, WGS, and WSDOT: 24 stations by year’s end 2005, 33 by year’s end 2006 covering and area from Centralia to the Canadian border, Olympic to Cascade mountains with subnets in the Spokane and Tri-Cities regions
13. - By 2009, the WSRN reaches 85 stations covering 80% of Washington State, and 104 stations by 2011 covering 95% of the state
14. - January 1st 2013, the WSRN implements parallel servers, to provide services referenced to both NAD83-CORS96 Epoch 2002.00 and NAD-2011 Epoch 2010.00
Outreach
The WSRN continues outreach to the user community and potential beneficiaries of such networks in our region and in other parts of the Pacific Northwest. The WSRN holds user meetings to exchange tips, tricks, solutions, and ideas, and presents at industry conferences like the LSAW (Land Surveyors Association of Washington), ACSM, ASPRS, APWA, URISA and others by request. Materials and papers from these presentations are available on request. The WSRN has also presented to other regions interested in developing their own networks in other states and internationally, to include publication in industry periodicals
Regional Partners
The WSRN also exchanges data streams from jointly utilized CORS with Pierce County Public Works (who operate their own RTN which is open to the public), Oregon Department of Transportation (ODOT) who operate the RTN in Oregon, and with several CORS operators in Canada and Idaho to provide seamless network services up to each border
WSRN for GIS and Asset Mapping:
For an explanation of the what GNSS corrections are, how they can be applied to field mapping for GIS and Asset mapping, and the role the WSRN can serve in this process, can be downloaded here.
WSRN station names explained:
For an explanation of the 4-letter site codes, as brief list of station names can be downloaded here.
WSRN Contacts:
Gavin Schrock, PLS - 206-684-5630 - gavin.schrock@seattle.gov
Dean Huber - Ph: 206-233-7805 - dean.huber@seattle.gov
Forest McBrian - Ph: 206-514-0237 - forest.mcbrian@seattle.gov
Hunter Eastman - Ph: 206-549-6286 - hunter.eastman@seattle.gov - ABSENT UNTIL JUNE 2024
Oregon Department Of Transportation (ODOT) RTN Contact:
Randy Oberg, PLS. Lead Geodetic Surveyor, Oregon Department of Transportation, Technical Manager, Oregon Real-time GPS Network - (ORGN) http://www.TheORGN.net - 4040 Fairview Industrial Dr SE, MS 4, Salem, OR 97302 - Phone: 503-986-3041 - Cell: 503-881-2889 - randy.d.oberg@odot.state.or.us
NO WARRANTIES; LIMITATION OF LIABILITY
Use of WSRN services, applications and features of this website, or any information contained on this website or through any links provided on this website is at the user's sole risk. The WSRN, WSRN partners, and Seattle Public Utilities provides WSRN Services on an 'as is' basis. Neither WSRN members, nor Seattle Public Utilities, its officers, employees, vendors, or third-party service providers (collectively or individually) makes any express or implied representation or warranty of any kind with respect to WSRN Services. By way of example and not of limitation, there is no representation or warranty (a) that WSRN Services will be uninterrupted or error-free, (b) that the results obtained from using WSRN Services will be accurate, reliable, complete or current, or (c) of merchantability or fitness for a particular purpose. WSRN Services and information related thereto are subject to change without prior notice.
Neither Seattle Public Utilities nor the subscriber, or WSRN members, is liable for any damages arising out of or in connection with WSRN Services, including without limitation mistakes, omissions, interruptions, deletion of files, errors, defects, viruses, delays in operation or transmission, or failures of the Continuously Operating Reference Stations (CORS). This is a comprehensive limitation of liability that applies to all damages of any kind, including compensatory, direct, indirect or consequential damages, loss of data, income or profit, loss of or damage to property and claims of third parties.
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