NovAtel CORRECT™ with PPP
NovAtel CORRECT with PPP combines GNSS satellite clock and orbit correction data from TerraStar's global reference station network with NovAtel's OEM7™ receiver algorithms to yield robust positioning without the need for nearby base stations.
Correction data provided by TerraStar is delivered to the end user via satellite. With TerraStar satellites visible globally, NovAtel CORRECT with PPP is an ideal solution for precision applications where communications infrastructure is either unreliable or not available. In addition, applications where signal interruptions are common will benefit from a more robust positioning solution with the ability to quickly regain full accuracy following a temporary loss of GNSS signals.
- Rapid re-convergence after GNSS outages
- Maintains decimetre solution through correction outages of up to 5 mins
- Decimetre to sub-decimetre solutions available for any application
- End-to-end NovAtel single source solution including hardware, services and support
- Seemless integration with other NovAtel CORRECT positioning modes
- Reliable positioning even in difficult environments
- Simplifies equipment needs by eliminating base station
- Sole source for GNSS hardware and corrections
Precise Point Positioning (PPP) is a GNSS positioning technique that yields sub-metre-level or better positions by combining global GNSS satellite and signal corrections with GNSS receiver error modelling and position estimation algorithms.
The correction data required for a PPP solution includes GNSS satellite clock, orbit and signal-bias corrections generated from a network of global reference stations. Once the corrections are calculated, they are delivered to the end user over satellite- or the Internet. These corrections are used by NovAtel CORRECT on a dual-frequency OEM7™ receiver, resulting in sub-metre-level or better positioning with no base station required.
A typical PPP solution requires a period of time to converge. This convergence period is necessary to estimate local measurement biases. The actual accuracy achieved and the convergence time required is dependent on the quality of the corrections, local-observing conditions, and the sophistication of the receiver algorithms.
If the PPP corrections and receiver algorithms are sufficiently advanced, then PPP ambiguity resolution is possible. Ambiguity resolution refers to the determination of the integer number of cycles in the ambiguous carrier-phase measurements. With the ambiguities resolved, the full accuracy of the carrier-phase measurement is unlocked. This, in turn, yields a corresponding improvement in solution accuracy. With a high-quality correction feed, such as that available through TerraStar, even RTK-level accuracies are possible. PPP ambiguity resolution also improves the ability of a PPP solution to recover following signal interruptions: without ambiguity resolution, there can be discontinuities and re-convergence periods in solutions following signal interruptions; with ambiguity resolution, solutions can instantly recover to full accuracy.
PPP ambiguity resolution is possible on NovAtel's OEM7 receivers with a TerraStar-C subscription.
Since PPP solutions are not dependent on a local reference receiver or network, users can achieve centimetre or sub-decimetre positioning in areas where it is not practical to use traditional RTK techniques. Delivery of the correction data over L-band satellite means any user who can see the satellite has access to corrections, making PPP an ideal solution for precision applications in areas where communications infrastructure is either unreliable or not available.
TerraStar Subscription Service Levels
Two Subscription-Based Services Available:
NovAtel’s vision is to solve position, anywhere, anytime. This can be particularly difficult when operating environments present challenges like tree lines or partial obstructions from buildings, or when traditional RTK infrastructure is unavailable. TerraStar correction services offered by NovAtel can help solve those tough positioning problems by delivering GNSS corrections via L-band frequencies to your receiver.
We offer high precision and broad accuracy solutions:
TerraStar-C (4 centimetre accuracy)
This high accuracy service is ideal for real-time pass-to-pass applications requiring centimetre-level repeatability and for high precision applications where no base station is available.
TerraStar-L (40 centimetre accuracy)
For broad accuracy applications, TerraStar-L maximizes uptime and productivity. A real-time solution with fast initialization, it improves upon uncorrected positioning modes by providing a reliable decimetre position regardless of how challenging the operating environment.
|Horizontal Accuracy (RMS)||40 cm||4 cm|
|Vertical Accuracy (RMS)||60 cm||6.5 cm|
|Convergence Time||5 min1||30-45 min2|
1. Calculated from 7 day static data in Calgary. Accuracy will vary with observing conditions.
2. Convergence times dependent on observing conditions including number of visible GNSS signals, level of multipath and proximity to obstructions like large trees or buildings.