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Geodetics RTD Software. Reference Station Networks using Geodetics' RTD Software. April 2004 www.geodetics.com. About Geodetics.
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Geodetics RTD Software Reference Station Networks using Geodetics' RTD Software April 2004 www.geodetics.com
About Geodetics Geodetics, Inc. is a software company based in La Jolla, California. It specializes in high-precision, real-time position and navigation solutions based on its proprietary Epoch-by-Epoch™ technology. Geodetics and Thales Navigation have partnered to offer a network RTK solution.
RTD Family of Products RTD-Pro:Continuous monitoring of static/dynamic dual-frequency GPS receivers operating in a network includingserver/client connectivity enabling Epoch-by-Epoch™ RTK. RTD-Net :Solution for continuous monitoring of permanent GPS networks operating dual-frequency receivers. Excludes server/client connectivity. RTD-L1:For short-baseline deformation monitoring applications. RTD-Data:Receiver control and data storage functionality without network processing. RTD-Postprocess:Fully automated GPS post-processing software. RTD-Vector:Fully automated GPS based attitude determination software system RTD-Clients:Epoch-by-Epoch™ processing for client side.
Geodetics’ Applications Fleet Tracking RTK Surveying Deformation Monitoring Structure Monitoring Precise Navigation Marine
Single Baseline RTK 10-20 km radius Single RTK Rover Single RTK Base
Issues with Single Baseline RTK Overhead: Must own, setup and survey base station Availability: Single point of failure Reliability: No redundancy (i.e. multiple determination) Accuracy: Limited range (10-20 km) and baseline dependent Initialization/Re-initialization: Seconds to minutes Security: Must attend temporary base station Productivity/Efficiency: Low (see all of the above) Flexibility: Mixing of receivers/antennas problematic
Solution: Network RTK with Geodetics RTD software Fully automatedGPS sensor network softwarefor multiple static and dynamic platforms • RTD is a fully automated client-server application designed for real-time, high-precision GPS sensor tracking applications. RTD uses Geodetics proprietary Epoch-by-Epoch™ algorithms that provide instantaneous integer-cycle phase ambiguity resolution. • The RTD server centrally controls a network of GPS base stations through a full suite of data communication, processing, and archiving functions. Data are made available to multiple clients through the Internet for real-time positioning with centimeter-level accuracies.
Network Integrity Monitoring RTD On-The-Fly Adjustments for Static/Dynamic Reference Stations Platform Independent
Standard RTK • Enhanced RTK • Smart Client RTD Server/Client Architecture Field Client Server Wireless Supports RTCM, CMR and CMR+ RTK Formats Platform Independent
RTK Clients Operating in OCRTN Geodetics Smart Client Trimble 5700 Ashtech Z-Extreme Leica SR530
RTD-Pro Demo Reference Network RTD Real-Time Demo Hardware Independent
Advantages over Single Baseline RTK Overhead: Reference station infrastructure fixed and supported Availability: Eliminates single point of failure Reliability: Enables multiple determination for high reliability Accuracy: Extended range (50 km) Initialization/Re-initialization: Instantaneous with EBE Security: No need to attend reference stations Productivity/Efficiency: high (see all of the above) Flexibility: Mixing of receivers/antennas handled by system
Advantages over Single Baseline RTK Network RTK Benefits • Multiple Beneficiaries (for example) • Surveyors • GIS Data Collectors • City Services (Fleet Management/Asset Tracking) • Get More Work Done With Same Crew Size • Autonomous Field Crews • Reference Coordinates are Known/Controlled by System Operator • Potential Revenue Generator • The System could pay for itself within one or two years through increased efficiency, reduced labor, and savings related to hardware purchases
Geodetics Client RTK • Client computes Epoch-by-Epoch™ (instantaneous) solutions. • Multiple simultaneous baselines computed. • Utilizes any reference receiver (does not require RTK software). • Can utilize L1 only receivers on short baselines ( < 5km). • Works on laptops, tablet PC’s and PDA’s. Epoch-by-Epoch™ technology with Carlson SurvCE will provide a Turnkey surveying solution with network connectivity.
Solution: Network RTK with Geodetics RTD software • Integer-cycle phase ambiguities are resolved independently at each epoch for a network of GPS receivers. • Relative site positions estimated to cm-precision with only a single epoch of GPS data from 5 or more satellites, providing “true” RTK. • Special treatment of atmospheric effects on client allows extended rangeseveral times the maximum distance achieved by RTK systems. Uses “real” reference stations. Nothing “virtual” about it.
Other Features • Designed specifically for real-time wireless networked environments. • Works with geodetic-quality GPS receivers (dual and single frequency). • Accuracy gracefully degraded based on GPS data availability at each epoch. • Precise relative positioning of moving platforms (no base station required).
Epoch-by-Epoch™ vs Traditional RTK • Immediate (one-epoch) initialization and re- initialization vs. 15 seconds to several minutes, for ambiguity fixing. • Unaffected by cycle-slips and constellation changes. • Easier to detect and reject erroneous data points • Multiple vs. single base receiver operations • Extended range
RTD-Postprocessing Postprocess Demo
RTD-Vector Vector Demo
Deformation Monitoring in New Zealand • Geodetics’ RTD software with Epoch-by-Epoch™ positioning was used to analyze the New Zealand National GPS Network with a spatial extent of ~ 1500 km. The network spans the North and South Islands, with a maximum site separation of 500 km. • The following are the analysis results: • Single epoch precision is comparable to networks of smaller extent (1-2 cm in the horizontal, 5-10 cm in the vertical). • The scatter of the hourly medians is well below 1 cm in the horizontal components and 1-2 cm in the vertical. • The Epoch-by-Epoch™ troposphere estimates are very clean. • The number of outliers (> 3 s) is very small for the entire data set (about 0.1%). 24 hour RTD solution
Dam Deformation: Diamond Valley Lake • Largest water reservoir in southern California - 6 mo. emergency water supply. • Three earthen dams • 7 Leica receivers sampling at 1 Hz • Maximum distance 8 km • Data streaming by radio modems • Real-time instantaneous solutions with RTD, with alarming features. • Internet accessible Raw data and photo courtesy of Mike Duffy and Cecilia Whitaker, Metropolitan Water District of Southern California
Minimum System Requirements • One Reference Station With Data Link to Central Processing Facility (maximum 30 stations). Modem/DSL/TCP/Radio • RTD Processing Server (Windows NT, 2000, XP) • 1 GHz Processor, 512 MB RAM, 40 GB HD, Windows • Communications from client to server (wireless modem – GSM/CDPD/GPRS) • Optional for extended range, Epoch-by-Epoch™ positioning: PDA with Geodetics Smart Client. • Additional sites can be added to existing network easily.
Geodetics, Inc. provides Epoch-by-Epoch™ positioning and navigation products for extended range, high-precision, real-time applications • www.geodetics.com • Tel: (858) 729-0872