Will Starlink Satellites Be Used For RTK GPS? When Starlink launched, most people in remote areas had the opportunity to access high-speed internet for the first time.
Thanks to the Satellite constellations on low orbits, the technology allowed faster communications.
But what if these constellations are used as backups for GPS?
In this article, we’ll see how it may be possible to use Starlink satellites as real-time kinematics(RTK) GPS.
Table of Contents
- What Is A GPS RTK?
- How RTK Works
- What Is Starlink GPS?
- What Causes GPS Positioning Errors?
- Will Starlink Satellites Be Used For RTK GPS?
- Conclusion
What Is A GPS RTK?
Real-time GPS tracking
Real-time kinetics is a technology used in GPS tracking that provides location data with more accuracy, typically within a few centimeters.
RTK technology incorporates regular GPS readings and adds a correction error to enhance accuracy.
How RTK Works
Space satellites orbiting around the earth
First, RTK uses GPS technology and enhances how it works to the nearest centimeter.
A normal FGPS setup has one module, but the RTK uses the BASE and the ROVER modules to transmit signals.
The ROVER module is dynamic and moves around the object to get an accurate reading.
The BASE station module in normal GPS gives the precision of an object but with an error.
In an RTK setup, the error reported in the BASE station is sent to the ROVER and adjusted to give the object’s exact position.
All this happens in real-time through UHF and radio modem bands as they are stable over long distances.
What Is Starlink GPS?
Basic Starlink kit
Starlink made their constellation satellites to communicate with the mesh kits for purposes of internet and connectivity.
However, scientists have discovered the same technology can be used as an alternative GPS communication with satellites.
The massive Starlink satellites provide location information at low latency, which is more accurate than GPS.
While Starlink may be a backup GPS, SpaceX needs to tweak a few things.
Firstly, the satellites require the necessary ground structure and payload to relay data from the constellations.
Also, the constellation must achieve complete coverage, which takes several years.
What Causes GPS Positioning Errors?
GPS’s technology to receive signals and calibrate location is based on the time taken to receive the signal. But, GPS satellite signals are prone to interference like any other electromagnetic wave.
This interference causes positioning errors that sometimes go up to several miles. Some common causes of GPS positioning errors include:
- Ionospheric interference. The ionosphere is the layer of ionized air between 50 and 500 km. GPS signals passing through this line are refracted, resulting in erroneous calibrations up to ten meters lateral error.
- Tropospheric interference. Tropospheric interference occurs in the lowest atmosphere of the earth, which has weather changes affecting the GPS calibrations. While the troposphere has more interference, the effect on GPS positioning is minimal and is easily corrected by remote antennas.
- Multipath errors. Multipath errors come from the fact that a GPS signal cannot differentiate objects. So, if you have a car and a house in front, the GPS may give results of the nearest object instead of the real one. It is really hard to correct multipath errors, although mounting antennas helps give a more accurate reading.
- The number of visible satellites. The receiver needs more satellites to give accurate results as it compares the signals from each satellite. Obstructions such as buildings, electronic interference signals, and dense trees can affect the visibility of satellites.
- Satellite geometry. Satellite geometry refers to the relative position of satellites at any given time. When taking location information, the satellites must be at wide angles for accurate results. If you take readings when the satellites are close or clustered in a straight line, the geometry is poor.
Will Starlink Satellites Be Used For RTK GPS?
Although Starlink intended to create a simple satellite internet solution, we have seen how it is possible to extend its uses to GPS navigation.
With a few tweaks, the system can learn how to calculate the actual position of objects and images with impressive accuracy.
Scientists have researched Starlink’s possible role in navigation by studying over 1000 Starlink satellites.
Each satellite’s orbit around the Earth can be a tool for positional reference. In a recent study, the researchers discovered a GPS location using six satellites.
While the accuracy was to the nearest 7 meters, it was a significant milestone and close to the current GPS (0.3 – 5 meters).
Starlink plans to launch more than 3,000 satellites in the future, which may enhance real-time navigation.
The reverse-engineering process using low-earth orbit satellites was done without assistance from Space X, and the researchers indicated you could learn the system and use it for navigation.
While Starlink is silent on this issue, more technological leaps may nudge the company to consider integrating the navigation system.
Using Starlink’s satellites for navigation has the potential to unlock plenty of benefits in multiple industries.
For instance, it will play a vital role in autonomous vehicle systems, which require precise calibrations of positions.
Starlink’s satellites already have a low latency due to the distance to Earth.
This will significantly contribute to the speed at which the systems provide data.
Car navigation system
GPS technology has lasted several decades, and while Starlink may not be intrusive to phase it out, it can work as a backup alternative.
Military and government organizations can incorporate Starlink’s satellite technology to provide accurate data when the GPS systems are weak or unavailable.
It can be useful in remote areas or places with heavy foliage.
Conclusion
As SpaceX continues to launch more satellites, Starlink provides a reliable broadband network globally.
The growing constellation of satellites may bring another positive effect to the navigation world.
It is known that GPS interference has affected the accuracy of positioning.
Real-time kinetics has helped GPS accuracy, and the same technology can be learned in Starlink’s satellites.
Starlink’s satellites, when reverse-engineered, can provide accurate location information up to the nearest centimeter.
We’re not sure Starlink will adopt this idea and use it to expand its services to global positioning, but the space tech company might likely consider it.
