1. Geodetics RTD Software
Reference Station Networks using Geodetics' RTD Software
April 2004

2. 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.

3. RTD Family of Products
RTD-Pro: Continuous monitoring of static/dynamic dual-frequency GPS receivers operating in a network including server/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.

4. Geodetics’ Applications
Fleet Tracking
RTK Surveying
Deformation Monitoring
Structure Monitoring
Precise Navigation
Marine

5. Single Baseline RTK
10-20 km radius
Single RTK Rover
Single RTK Base

6. 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

7. Solution: Network RTK with Geodetics RTD software
Fully automated GPS sensor network software for 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.

8. Common RTD User Interface

9. Network Integrity Monitoring
RTD
On-The-Fly Adjustments for Static/Dynamic Reference Stations
Platform Independent

10. RTD Server/Client Architecture
Field Client
Standard RTK
Enhanced RTK
Smart Client
Wireless
Supports RTCM, CMR and CMR+ RTK Formats
Platform Independent

11. Geodetics Smart Client
RTK Clients Operating in OCRTN
Geodetics Smart Client
Trimble 5700
Ashtech Z-Extreme
Leica SR530

12. RTD-Pro Demo
RTD
Real-Time
Demo
Reference Network
Hardware Independent

13. 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

14. 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

15. 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.

16. 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 range several times the maximum distance achieved by RTK systems. Uses “real” reference stations. Nothing “virtual” about it.

17. 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).

18. 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

19. RTD-Postprocessing
Postprocess
Demo

20. RTD-Vector
Vector
Demo

21. 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

22. 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

23. Competition RTD vs. VRS Feature RTD VRS Operation - Time to fix
Epoch-by-Epoch™ Instantaneous
Rapid Static 15sec – 4min
(depends on rover RTK)
Operation – Extended range
Up to 50Km baseline with L1/L2. Up to 5Km with L1 only
Unclear
Robustness - Simultaneous computation of multiple baselines
Yes (limited by bandwidth) No
Robustness - Base station movement assumption
Yes
No - Assumed fixed base station coordinates
Price - Independent of number of clients
Applications - Suitable for dynamic applications (UPS, trash collection, AVL etc…)
Yes. Epoch-by-Epoch™ is ideally suited to dynamic applications
Not optimal.

24. RTD Installations (partial list)

25. 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.

26. Geodetics, Inc. provides Epoch-by-Epoch™ positioning and navigation products for extended range, high-precision, real-time applications
Tel: (858)