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Global Differential GPS System
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Orbit & Clock States

The precise real-time GPS orbit and clock states are the core products of the Global Differential GPS (GDGPS) System, from which many other by-products and services are derived. We ensure that these are the most accurate real-time representation of the GPS constellation state by employing the largest real-time tracking network with nearly 100 global sites, and the most sophisticated and complete GPS modeling and orbit determination software.

Below is a summary of the key attributes of these products:

< 20 cm 3D RMS
< 20 cm RMS (after de-biasing)
< 10 cm RMS
Latency 1 minute
Format SP3c, GIPSY (pos_goa, TDP), GDGPS streams
1 minute
1 Hz
Access mode sFTP

The GDGPS orbits are typically accurate to better than 20 cm 3D RMS, and the clocks are accurate to better then 20 cm RMS. Figure 1 below is updated daily to provide an independent assessment of the quality of the orbit solution by comparing it with the JPL precise daily solutions, which are accurate to a few centimeters.

Figure 2 below shows the accuracy of the clock solution for the past 14 days by comparing with JPL precise clock solution which is also accurate to a few centimeters. This figure is also updated daily.

Figure 3 below shows the User Range Error (URE), which is the effective combined accuracy of the orbit and clock solutions, for the past 14 days by comparing with the JPL precise orbit and clock solutions. This figure is also updated daily.

The orbit and clock products are provided as ASCII files in various formats, including the industry standard SP3c, and internal GIPSY formats. The files are available through secure FTP from our redundant servers. The files are available either as 1 minute 'chunks', or as 24-48 hour files, containing the real time solutions over the last 24 to 48 hours. The orbit and clock states are provided every 1 minute. For lower latency (seconds) and higher frequency (1 Hz) products see the Orbit and Clock Corrections product.

We'll be happy to customize this product for your needs.

Real-time GNSS
Products & Services
Precise, Global, Reliable
- Embedded Autonomous Ephemeris Prediction (AEP) software
- Orbit & Clock Corrections
- Orbit & Clock States
- Broadcast Ephemeris & Almanac
- Complete 50 bps Navigation Message
- Global Ionospheric (TEC) Maps
- Raw Measurements
- Predicted Orbit & Clock States
- Integrity & Performance Monitoring
- Global Virtual Reference Network
- Assisted GPS Data
- Assisted GLONASS Data
- GLONASS corrections, orbit and clocks

- Automatic Precise Positioning Service
- Consulting
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