RGNSS module
The RGNSS (Relative Global Navigation Satellite System) Module takes as input the raw data provided by the GNSS receiver on-board a vehicle and the raw data received from other vehicles on real-time.
By combining these measurements a highly accurate relative position can be obtained and this accuracy is the basis for further processing that will enable the prediction of the relative dynamics of the vehicles on the road.
In the following picture we can see the scattering presented by the absolute measurement provided by most GPS receivers. It is clearly shown that for a static receiver the GPS calculated positions can have an error in the range of 15 meters. Those errors make this working mode useless for precision applications such as REPOSIT.
If we use Relative GNSS processing instead, we will benefit from a perfomance increase as depicted in the following plots. The first one represents the error in the modulus of the relative vector between two receivers, or in other words the error in the distance calculated between the two receivers. In this case, the quality of the receiver has a big importance in the performance as the resulting error is driven by the quality of the clocks of each receiver. This first image, represent the performance of a low-cost receiver such as the one used for the absolute scattering plot depicted above. Being an apples to apples comparison, we can see that the error has decreased from more than 15 metres in the absolute mode, down to 4 meters in the relative mode.
If we use instead a good quality receiver with more stable clocks and less noise, we can achieve sub-meter accuracy as depicted in the plot below.
