Will Starlink satellites be used for RTK GPS? GPS is a significant tool in surveying and picking out the location of an object.
However, it’s less accurate than an RTK GPS and features errors in the actual object’s positioning.
RTK GPS provides results with an accuracy of up to 10cm, making it a viable tool for precise applications. In today’s guide, we explore the possibility of using Starlink’s constellation for RTK GPS.
What Is a GPS RTK?
GPS Tracking.
The RTK in GPS RTK stands for Real-time Kinetics. It’s a variation of the conventional GPS that features improved location data accuracy.
The technology features a mechanism for providing a correction error to the typical GPS location data. This results in more precise location data within a few centimeters of an object’s location.
What Is Starlink GPS?
Performing topographic survey using GPS.
The Starlink satellites in low earth orbit (LEO) are useful in communicating with ground towers to distribute the internet to all places. It is key to getting internet service even in marginalized areas.
However, researchers have found Starlink technology a viable alternative to the typical GPS modus operandi.
Nonetheless, this would require Starlink to modify its current setup to accommodate it.
For instance, they need the ground infrastructure and payload to ensure satellite data transmission.
In addition, Starlink needs to launch more satellites into space to ensure they cover the entire globe for GPS use.
Such an improvement would take quite some time to realize, possibly years.
How does RTK work？
A GNSS RTK Receiver.
The typical GPS has only one feature- the Base station module. It is responsible for providing a rough location of an object with a significant degree of error.
Nonetheless, a GPS RTK features a Rover module as a complement to the base station module.
Therefore, when the latter provides an object’s generic position, the rover module corrects the error in the location reading.
Usually, the rover module is mobile, which is significant in moving around the object and correcting the original inaccurate reading.
The GPS RTK works in real-time, hence the name Real Time Kinetics (RTK).
Its UHF transmitter sends the signals to the receiving device, enabling accurate real-time tracking of an object’s location.
What Causes GPS Positioning Errors?
A Satellite orbiting the earth.
The time taken for the GPS signal to be relayed is a pertinent determinant of if there are positioning errors. Hence, an error will arise if there’s an electromagnetic interference during the transmission process.
So, what are some of these interferences, and how do they affect positioning:
Limited Satellites
The GPS accuracy depends on the available satellites within the line of sight. If they are limited, you can expect positioning errors. When interference is near the object, it may conceal the available satellites.
The low satellite visibility will also hamper proper GPS positioning and thus lead to an inaccurate location.
Ionospheric Interference
GPS signals traveling through space must pass through the ionosphere. This layer (between 50 and 500km) refracts the GPS signals. The profound effect leads to lateral errors that can reach 10 meters.
Multipath errors
Take a case of an object located among others, such as a car near a building. When seeking the car’s location, the GPS may instead give the location of the more dominating object (the house).
It is an example of a multipath error and can be corrected by having antennas on the object of interest.
Satellite Geometry
Where is a satellite located at a particular time? The ideal location is at a wide angle for accurate readings.
But if they are too close to one another, their transmission will be hampered. They’ll most likely provide an inaccurate reading.
Tropospheric interferences
Like the ionosphere, the troposphere also interferes with the GPS signals.
It is the lowest atmospheric layer, although its effects are not as profound as those of the ionosphere.
All that is required to correct it is a remote antenna on the receiving device.
Will Starlink Satellites Be Used For RTK GPS?
A Starlink Satellite in Space.
Starlink satellites remain a viable option for RTK GPS. Research has been done on about 1,000 Starlink satellites that provided GPS signals with an accuracy of approximately 7 meters. It is slightly inaccurate than the present RTK GPS, which has an accuracy of 0.3 and 5 meters.
Further research is ongoing, and Starlink intends to send more satellites (about 3,000) to space for an improved internet connection.
Their presence may improve GPS accuracy and prompt Starlink to consider setting up GPS services.
Note that the research carried out earlier was performed without SpaceX’s input. The company has been non-committal to venturing into the GPS services trade.
But if the possibility for improved accuracy is proven, Starlink may consider setting up the navigation system.
Advantages Starlink RTK GPS
An Autonomous car relies heavily on RTK GPS.
What would a Starlink GPS rollout mean? Here are the two main advantages:
- First, it would be crucial to the success of futuristic autonomous vehicles. High precision in location calibrations is necessary for this technology to work, and Starlink’s GPS would provide it.
- Also, the location of Starlink’s satellites in LEO would be a huge plus to the GPS technology. It means signals would travel shorter distances (hence low latency) and thus boost GPS speeds.
GPS RTK Module Applications
Surveyors setting up a pair of Global Navigation Satellite System
- Machine Control
- General Navigation Uses
- Autonomous Drive Sytems
- Precision Farming, such as the use of drones in spraying
- Precise Surveying and Mapping
Conclusion
Nothing beats the precision of RTK GPS, and Starlink’s constellation could be the remaining jigsaw part to boost its effectiveness.
The internet company has huge potential to improve the current GPS setup thanks to its thousands of satellites in space.
They are yet to warm up to investing in navigation systems. But once they do, it’ll be a significant game-changer.