Overview
Introduction
The u-blox PointPerfect Flex service provides high-precision GNSS correction data to improve positioning accuracy. It delivers corrections in the SPARTN or RTCM format. This guide focuses specifically on receiving PointPerfect Flex corrections in SPARTN format via NTRIP. The SPARTN format is a compact and bandwidth-efficient correction data format optimized for real-time GNSS applications. It is fully compatible with u-blox high-precision receivers like the F9 and F20/X20, making it ideal for use with the PointPerfect Flex service.
For details on RTCM over NTRIP or other delivery options, refer to:
- PointPerfect Flex RTCM over NTRIP Distribution
- PointPerfect Flex Getting Started
- PointPerfect Flex Service Description
Benefits of the NTRIP distribution protocol
Accessing PointPerfect Flex corrections data via the NTRIP protocol provides several advantages:
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Easy configuration: The widely used NTRIP protocol is supported by many high-accuracy GNSS devices out-of-the-box. Simply configure your NTRIP client with the authentication credentials provided in the Thingstream device management portal at https://portal.thingstream.io/. See more details below.
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Improved time to first RTK fix (TTFF): Connecting to the PointPerfect Flex service through the NTRIP protocol provides instant delivery of the first complete set of corrections data to the GNSS receiver, enabling rapid calculation of high-accuracy RTK fixes.
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Do's & Don'ts: Best Practices and Common Pitfalls
Do's:
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Ensure stable network connectivity: A reliable internet connection is crucial for uninterrupted access to NTRIP correction data. Periodic drops in connection can degrade positioning accuracy.
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Select the correct NTRIP mountpoint: Use the appropriate mountpoint for your region (EU, NA, etc.).
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Keep your F9 or X20 receiver firmware up to date: Regularly update your receiver firmware to ensure compatibility with SPARTN corrections and to benefit from performance enhancements, bug fixes, and new features.
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Verify SPARTN compatibility with your NTRIP client: Not all NTRIP clients support the SPARTN format. Ensure your client is compatible to avoid issues like checksum errors.
Don'ts:
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Don't use 3rd party GNSS receivers: SPARTN corrections are optimized for u-blox GNSS receivers like the F9 and X20. For non-u-blox receivers, use RTCM/NTRIP corrections instead.
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Don’t exceed geographic boundaries: Ensure your receiver operates within the coverage area of the PointPerfect Flex NTRIP service to avoid receiving corrections outside the intended service range.
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Don't share NTRIP credentials: Sharing your login credentials may lead to unauthorized access, disruptions in service, or potential account suspension.
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NTRIP Protocol Versions and Secure Delivery
PointPerfect Flex supports both NTRIP protocol versions 1.0 and 2.0, automatically detecting which version is used by the GNSS receiver’s NTRIP client. Secure connections using TLS encryption are also supported and recommended as long as the receiver’s NTRIP client is compatible with TLS.
Here is a diagram describing the communication of SPARTN via NTRIP:
Configuration
Each Thingstream PointPerfect Flex device (‘Thing’) is provided with unique username and password credentials for the NTRIP service. These credentials are exclusive to one simultaneous NTRIP client connection. If a second device attempts to connect using the same credentials, the first device will be disconnected.
For more information on provisioning and obtaining the connection parameters and credentials see the Creating a Thing page.
Our NTRIP service requires a valid NMEA-GGA (GxGGA) message to be sent regularly to the caster in order to maintain connectivity. If no valid NMEA message is sent within 30 seconds, the connection will be dropped. To prevent a hard disconnect at the 30-second interval, we recommend sending this NMEA-GGA message every 10 seconds. A valid NMEA-GGA message must be within the expected time/location range, contain at least 4 satellites, must be presented in the right format, and the checksum must pass.
To enable PointPerfect Flex (SPARTN/RTCM) over NTRIP on the F9 module, you will need to connect your receiver’s client to the NTRIP caster and stream. Follow the steps in the PointPerfect Flex u-center guide to complete the setup.
Service to Service
For service to service (S2S), the user is responsible for distributing the localized corrections data, this requires additional configuration at the user backend to redistribute the service data to the devices.
To access the service via service-to-service approach, please contact us at services-support@u-blox.com
Still need help?
If you need more help or have any questions, please send an email to services-support@u-blox.com.
Reference Documentation
[1] ZED-F9P Integration manual, UBX-18010802
[2] u-center User guide, UBX-13005250
[3] u-blox F9 HPG 1.32 Interface description, UBX-22008968
[4] C099-F9P application board User guide, UBX- 18063024
[5] EVK-F9P-01 evaluation kit User guide, UBX-22038408
[6] Thingstream Knowledge Base – Services Support
[7] u-blox information on positioning and location technologies - What is NTRIP