A change you don’t see… but you notice
GPS technology has been part of the rally world for years. But if we look at it with a bit of perspective, we will see that today’s GPS is not the same as the GPS of a few years ago.
And not so much because the underlying technology has changed radically, but because we now understand better what it gives us… and what it does not.
In regularity, that nuance is fundamental.
Antenna and device: two parts that are often confused
When we talk about GPS, we often oversimplify it.
On one hand, we have the GPS antenna, which is the part that receives the signal from the satellites. This antenna does not send information, it simply listens.
On the other hand, we have the device, which receives this position data and processes it to turn it into useful information: speed, distance, time, route…
This distinction is important, because the final quality does not depend only on the signal, but on how it is handled.
How position is calculated (and what that means)
The receiver calculates its position based on the distance to several satellites (usually 4 or more), through a calculation system called trilateration.
This process is continuous. The antennas are constantly receiving signal, but that does not mean the information is instantaneous or perfect.
There are two key factors:
- the device’s processing capacity
- the position update frequency (1Hz, 10Hz...)
Each receiver works at a specific frequency and can process a certain amount of data. This limit exists, even if it is not always noticeable.
Movement and frequency: a factor that is often ignored
One aspect that often surprises people is that perceived accuracy changes when the vehicle is moving.
It is not that the GPS “works worse”, but rather that:
- position is calculated at intervals (1Hz, 5Hz, 10Hz…)
- in the meantime, the vehicle has already moved
At low frequency, the position arrives with delay; at higher speed this can be more noticeable.
If the frequency is high (10Hz or more), devices usually apply filters to stabilize the position.
That is why, in a rally context, a reading while moving is not exactly the same as a reading at rest, but stopping does not guarantee an immediate improvement either if the system is not given time to stabilize.
As of today, our recommendation is to do recce while moving and with a bit of speed, although we already know that this is not always feasible.
These are technical nuances that, in practice, end up having an impact.
Real accuracy: GPS is not infallible
A standard GPS offers accuracy that, under normal conditions, is within a few meters.
This means that:
- the position may shift slightly
- small deviations may appear
- two consecutive readings may not match exactly
When conditions are not good — roads boxed in by terrain, areas with obstacles, dense forests — this accuracy gets worse.
And here a key question appears.
How do you know if the position is good?
There is no simple answer.
But there is a practical approach that is very useful in rallies:
- checking the position against a map
If the position given by the GPS matches the actual road (the tarmac), then we have a good reference.
It is not a foolproof technique, but it helps validate whether the data is coherent.
And this is where having the map stops being an extra: it becomes a validation tool.
Coverage yes… but variable quality
Nowadays, GNSS systems (GPS, Galileo, etc.) have global coverage.
But that does not mean signal quality is always the same.
There are two factors that affect it:
obstacles between the antenna and the satellites
number of visible satellites
On canyon-type roads, or with stone walls nearby, it is common to see fewer satellites or receive bounced signals.
The result is clear: we have position… but less precise.
It’s not all GPS: the importance of constellations
Another relevant change in recent years is that receivers no longer work only with GPS.
Today, many devices use several constellations:
- GPS (USA)
- GLONASS (Russia)
- Galileo (Europe)
- BeiDou (China)
This improves satellite availability and, as a consequence, the quality of the position.
Where does the real-time data come from?
Another point that often goes unnoticed is how the data from each participant reaches the base.
In most current rallies, timing data is transmitted through the mobile network (2G, 3G, 4G, 5G). And here we depend on coverage, this time mobile coverage.
This data reaches the cloud, a space on a server that has to be sized and contracted. It is processed and managed with maximum speed; we can say in real time.
This has evolved a lot in recent years and makes it possible to manage large volumes of information with much greater reliability and speed.
That is why we can now have timing data very quickly,
and tracking data also quickly, but with delays depending on mobile coverage.
Devices with satellite communication: another world
Here we need to make a clear distinction.
There are devices that, in addition to receiving signal, communicate directly with satellites.
These are the systems mainly used in raids and events in remote areas. Their main function is safety and tracking.
They have different characteristics:
- They request and transmit position to the satellite every certain amount of time (2, 5 minutes…), since communication costs are high.
- You gain independence from mobile networks and get the data directly.
- You obtain highly reliable data, vital in cases of emergency and accidents in remote areas.
And it is important not to confuse them with GPS tracking and timing systems for road rallies where there is safety staff present (marshals with radio).
They are different tools, with different goals.
The key point: the data is the same, the result is not
At this point, the conclusion is clear.
All teams start from the same information: a GPS position with certain limitations.
The difference is not in the signal. It is in how it is handled.
In regularity, the challenge is to turn this position into:
- a reliable distance, referenced to your roadbook
- a useful reference for driver and co-driver
- a valid repositioning reference for when you are doing the event
And GPS alone does not solve that.
When GPS becomes a real tool
This is where solutions specifically designed for this use come into play.
Devices like REGO, combined with map-based apps and recording tools, and the Blunik device, make it possible to:
- work on the stages before competing
- validate routes on real cartography
- add Blunik distance to every GPS point
- and improve data recording during your recce and in competition
Especially useful in
- regularity sport
- VHRS
- events with recce
The value is not in having GPS, but in knowing how to use it properly.
