high accuracy gps mapping and vrs
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High Accuracy GPS Mapping and VRS. Lanny Schnipper Seiler Instrument 2008 IGIC Conference Indianapolis, IN. VRS in Action. No base setup get to the job dial in Check start working MWRTK VRS in Indiana save time save money. Overview. Review GPS - PowerPoint PPT PresentationTRANSCRIPT
Seiler
High Accuracy GPS Mapping and VRS
Lanny Schnipper
Seiler Instrument
2008 IGIC Conference
Indianapolis, IN
VRS in Action
• No base setup – get to the job– dial in– Check– start working
• MWRTK VRS in Indiana– save time– save money
Overview
• Review GPS• Discuss use of Virtual Reference
Stations (VRS)• Obtaining highly accurate GIS/GPS
positions • Continuously Operating Reference
Stations (CORS) • Real-Time differential results
What is VRS?
• GPSNet, DGPSNet, RTKNet• Links a network of reference stations• Provides quality control of incoming
data• Logs files for post-processing• Network modeling of systematic
errors• Real time broadcast of true network
DGPS and RTK solutions
VRS Data Flow
Reference stations data streams back to the server through LAN, Internet, or radio links
VRS Data Flow
User’s receiver sends an NMEA string back to server using cellular modem. Virtual Reference Station position is established.
NMEA—GGA
VRS
VRS Data Flow
Server uses VRS position to create corrected observables and broadcasts them to the user end.
RTCM or CMR+
VRS
Why use VRS?
• Eliminates the need for Users to establish DGPS base/reference station(s)
• More reference stations = shorter vectors/ baselines
• Shorter baselines = less atmospheric errors
• Network atmospheric modeling• Extended operating range with
improved accuracy
Why use VRS?
• VRS provides integrity monitoring• All users in common, established
coordinate frame• Eliminates the dependency on single
base/reference station – Graceful degradation should a reference station
fail
• Uses established communications
Indiana MWRTK
26 Stations
…and growing!
Indiana MWRTK
www.mwrtk.net
Real Time in TerraSync/ArcPad
• External correction source– Data radio– Beacon-on-a-Belt (BoB™) receiver– GeoBeacon– SBAS (WAAS)
• TerraSync Version 2.30 (2/03) added VRS– Network VRS– Single base
• GPSCorrect Version 1.1 (4/05)
Support VRS corrections • GeoExplorer CE series with GPS
firmware version 1.03:– GeoXT– GeoXM– GeoXH
• GPS Pathfinder with firmware version 1.52 or later:– GPS Pathfinder Power– GPS Pathfinder Pro XRS– GPS Pathfinder Pro XR– GPS Pathfinder ProXH– GPS Pathfinder ProXT
Connecting to VRS
• Internet connection to the VRS server– GPRS-capable cellphone– WiFi Hotspot
• Serial cable connection– Data radio
• Start Settings Connections
– Make connection to your Phone or other device
– Test Internet Explorer to insure connection was successful
Outside TerraSync
Inside TerraSync
• Start TerraSync• Select Setup section• Set Real-time Settings– Choice 1 field select External Source.
• Configure the external source– From the Type field, select VRS– or select the Single Base option– Connection Method field, select Internet– Address field, enter the IP address or URL of the
VRS server.
– IP Address: 64.123.250.18 for MWRTK– IP Port: 2101 for MWRTK
Accuracy
• Submeter with a GeoXT/XH– Usually subfoot– We have even seen less than 6 inches!– No post-processing required
Subscription
• VRS is a paid subscription• Seiler provides Logon and password• MWRTK.NET
– Single Day - $20 per day, 3-day minimum per month maximum monthly charge $200(Billed monthly)
– Single Month- $150(Billed monthly and payable in advance)
– Single Quarter- $375 ($125 per month)(Billed quarterly and payable in advance)
– One Year- $1,200(Billed $225.00 per quarter and payable in advance)
Seiler
Questions?