What happens to Google Maps when tectonic plates move?
> In between, mapmakers figure, the error is swamped by the imprecision of mapping and GPS equipment. Future maps may be updated at a rate closer to real-time. “We have the technology now with GPS to be able to make those slight adjustments on a more frequent basis,” Craun said.<p>A French startup operates an impressive technical solution in this direction:<p>> new GNSS (Global Navigation Satellite Systems) augmentation services based on the PPP-CNES technology (Precise Point Positioning).<p>>     Absolute positioning accuracy of 4 cm (2D-95%)<i>, everywhere in the world, on the ground, on the sea and in the air, all the time, with only one receiver, without any nearby GNSS reference station: Precision, Availability and Integrity<p>>    </i>Depending on the level of service subscribed: Absolute positioning precision of 2, 4, 10, 50 or 80 cm (2D-95%)<p>> Compatible with GPS, GLONASS, BEIDOU and GALILEO constellations and mono and multi-frequencies receivers<p>I attended a meetup were they explained part of it. They have models for each of the aspects that can deteriorate precision and update all the parameters of all models in real time based on continuous measurements.<p>At a point during the development of the solution they had an unexplained discrepancy and tracked it down to some satellites of a common network being classifiable into two clusters of two different latencies (like, in the nanosecond range or even smaller). They contacted the network owners, listing the two clusters and asked "what is the difference between these and those satellites?".<p>The owners were a little confused. Something like "Well, inside each satellite, the cable from the antenna to the processing unit is a high performance transmission cable of tightly controlled specification, one inside each satellite. They happened to have been supplied in two batches with supposedly <i></i>strictly identical behaviour<i></i> up to the precision available at the time. And you sent us the exact listing of satellites matching batches A and B. But <i></i>how on earth have you got this list?<i></i> Were you spying into our internal archives?"<p>Answer: "no, we just have a model so precise that we could calibrate difference in transmission delays in your satellites from our receptor network on the ground".<p>Here's the startup Web site :
 <a href="http://www.geoflex.fr/?lang=en" rel="nofollow">http://www.geoflex.fr/?lang=en</a>