Using Septentrio's Receiver and Swift Navigation's Skylark correction services for precise positioning
GNSS (Global Navigation Satellite System) technology has changed the way we navigate and position ourselves, with applications in various industries including transportation, surveying and agriculture. However, atmospheric conditions and signal blockages can affect the accuracy of GNSS location information.
GNSS corrections are used to mitigate these effects and improve the accuracy of position measurements. In recent years, there has been a growing demand for high-accuracy positioning, which has led to the evolution of GNSS correction mechanisms such as OSR, SSR or LBand delivery. Standardization is not yet established, making it challenging for users to access and use these corrections.
To address this challenge, it is useful to create an ecosystem around GNSS corrections that is agnostic. This repository is part of a set of guides and documentation and explores a way of running Swift Navigation's Skylark corrections on your system quickly. Making it easy for users/integrators to evaluate and access these service. Platforms like Github enable documentation and the creation of demonstrators to allow users to try out different correction services with ease.
| To access the GitHub homepage to which this guide belongs, click here |
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| Name | GitHub |
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| Iker Uranga | IkerUranga10 |
| GitHub |
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| septentrio-users |
| Septentrio Support Page |
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| Contact | Septentrio Home Page |
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| Septentrio Contact Page | Septentrio Home Page |
This set of guidelines consist of a several practical examples to help Septentrio Module users and developers to integrate third party GNSS corrections. The guidelines are based on a concrete setup, which you may or may not use to follow the integration guidelines.
It is desirable to mention the disclaimer about that setup and the guides in general before starting reading this guide.
| Click here to know more about the Setup in which these guides are based and general implementation documentation disclaimer |
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- Introduction
- Who is Swift Navigation?
- What is Skylark?
- Known current limitations
- Is the project Open Source?
- Option 1: Using Skylark with NTRIP on board the receiver
- Option 2: Using Skylark with NTRIP client running in a Raspberry Pi
This repository consists in a how-to guide for the implementation of a system that uses a Raspberry Pi 4 Model B in combination with a Septentrio Module to obtain Swift Navigation's Skylark corrections for precise positioning. In this practical example case, mosaic-X5's Mosaic-Go Evaluation Kit is used, but any other Septentrio works in the same way if its connected with a USB cable. If you want to know more about or different modules and products you can visit us in:
Skylark is a wide area, cloud-based GNSS corrections service available in a suite of options—all delivering real-time, high-precision positioning.
If you have any questions or feedback, please don't hesitate to reach out to us at Septentrio support page.
Swift has the mission to build a safer and more efficient future by changing the way we navigate and understand every centimeter of our planet.
Swift delivers safe and precise positioning to keep the autonomous vehicles of today—and the future—in their lane. Swift continues to innovate with its ecosystem of precise positioning solutions for autonomous applications. They build on the foundation by offering a full suite of positioning solutions that are accurate, affordable and easily integrated while being reliable and secure for a variety of autonomous applications requiring precision positioning.
They value openness and participate in an open community, and when possible make our documentation, specifications, pricing and support available freely online. Swift products are designed and assembled in California, USA and benefit thousands of customers across the globe.
Swift Navigation’s Skylark is a wide area, cloud-based GNSS corrections service that delivers real-time high-precision positioning to autonomous vehicles, automotive, mobile and mass-market applications. Skylark delivers seamless corrections to continents across the globe including the United States, Europe, South Korea, Japan and Australia. Built from the ground-up for autonomy at scale, Skylark enables lane-level positioning, fast convergence times and high integrity and availability required by mass-market automotive and autonomous applications.
To know more about the service you can visit the following official web pages:
| Swift Navigation's official Skylark web page |
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| Skylark Product Summary document |
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| Click here to sign up to Skylark services now. |
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Note ℹ️ Although Swiftnav Skylark correction stream contains 3 constellations: Galileo, GPS and BeiDou; Septentrio Receivers are not compatible with the BeiDou correction data from Swiftnav, therefore GPS and Galileo are the only constellations currently used. To be highlighted as well is that the RTK Fix rate of Septentrio receivers, when using Skylark corrections, increases significantly if only GPS corrections are used, this is due to the correction quality difference for the different constellations.
This implementation guide for the Skylark correction services offered by Swift Navigation is open-source. That is, this repository does not contain any code created or modified by us, but is a guide to using the RTKLIB library or other techniques such as sharing the internet via USB cable from the Rapsberry Pi to the Septentrio receiver. Therefore, this guide could be modified thanks to the feedback of the users who use it, so you are welcome to leave us your opinion or suggestions for improvement.
SwiftNav works over NTRIP. Luckily all Septentrio receivers support NTRIP and have an NTRIP client embedded in the GNSS receiver. This can be accessed via the web-user interface.
A guide on how to use NTRIP in Septentrio receivers can be found here:
The mosaic receiver will need access to internet access in order to work properly. If connected to a PC you can enable internet access using the following guide:
The section below however make a setup of NTRIP using a Raspberry Pi setup which when together with the mosaic-go might alternatively use an NTRIP client running in the Raspberry Pi.
This method can be handy in the following circumstances: -When the user cannot share internet access from the processor to the mosaic-go in order to use NTRIP -When the user prefers to use a standard Serial port from the receiver
The instructions below try to mimic a customer CPU using in this case a Raspberry Pi.
Besides using the NTRIP client embedded in the receiver, the implementation of this service is based and tested on a specific setup. This setup consists of two main elements and their wiring and peripherals. These elements are the Mosaic-Go Module evaluation kit and a Raspberry Pi 4 Model B.
It is necessary to follow the instructions of the previous setup installation guide, to return to this point for the implementation of the Swift Navigation's Skylark corrections service.
Once the setup described above has been installed, the next step is to install a RTKLIB's tool called str2str, to be able to receive corrections from Skylark NTRIP Server/Caster to send them to the receiver and for to receive NMEA:GGA Messages from the receiver to send them to Skylark NTRIP Server/Caster.
RTKLIB:
RTKLIB is an open source program package for standard and precise positioning with GNSS (Global Navigation Satellite System). RTKLIB consists of a portable program library and several APs (application programs) utilizing the library. The Application Program we are going to use is str2str.
str2str:
str2str is an Application Program that receives input data from a stream and divides and outputs them to one or multiple streams. The input stream can be serial, TCP client, TCP server, NTRIP client, or file. The output stream can also be serial, TCP client, TCP server, NTRIP server, or file.
This repository provides a solution for a specific case where the input stream is a corrections provider that uses NTRIP. In this case, you should have the information (host, stream, password, etc.) of the NTRIP connection of the Correction Service Provider.
For the installation of the str2str tool, please following the next guide:
Once the installation of the str2str tool has been made, there is only one last step is missing, which is the execution of the tool with your NTRIP credentials and serial port configuration. This steps are show in next section.
Once the Receiver and Raspberry Pi setup and RTKLIB's str2str tool installation are done, the only step remaining is to execute the str2str tool as showed in the previous mentioned guide. Also, here is a generic example of the usage of str2str having NTRIP as an input source and Serial port as an output.
