Leuven, Belgium – Septentrio is proud to announce that its precise timing GPS receiver the PolaRx2eTR, features prominently in the OPERA experiment.* The results of this experiment would seem to indicate that neutrinos can travel at a velocity 20 parts per million greater than the speed of light – the speed accepted as the absolute speed limit ever since Einstein formulated his special relativity theory.
GNSS receivers are typically used to provide positioning information. Less commonly known is that they can also provide very precise timing information as well. In fact, precise time is at the heart of GNSS: each GNSS satellite is essentially a time beacon containing an ultra precise atomic clock.
Standard GNSS receivers can determine time with an accuracy of some 100 nsec to a few µsec. However, Septentrio’s precise PolaRx2eTR timing receivers run special algorithms that reduce errors even further. Moreover, specialised circuitry in Septentrio receivers allows measurement of the time offset between a local atomic clock and each of the individual GNSS satellite atomic clocks.
This, together with thorough time calibration procedures, allows the use of “common-view time transfer” – a standard technique used to synchronize atomic clocks around the world and indeed the technique used to synchronize the time bases at CERN and Gran Sasso (LNGS) in the OPERA experiment. PolaRx2eTR receivers at both CERN and LNGS compare their local clock to the clocks of the GNSS satellites commonly visible from both sites simultaneously. This allows researchers to synchronize the time at both laboratories to an accuracy of a couple of nanoseconds, the level needed to measure precisely the neutrino transit times that are now shaking the world of elementary particle physics.
“We are extremely proud that Septentrio technology has played a crucial role in such historic experiments,” observes Peter Grognard, Managing Director of Septentrio. “GPS technology would not be possible without the application of Einstein’s theories in various ways. It is remarkable to experience that this same technology has now been used to test and challenge these fundamental physical principles.”
A detailed description of the experiment, together with how Septentrio’s receivers were used to measure time, can be found in http://static.arxiv.org/pdf/1109.4897.pdf. More information and discussion of results can be found on www.cern.org.
*Additionally: as befits all thorough scientific work, the OPERA experimenters have invited scrutiny of their unexpected results. The test set-up and results have been thoroughly dissected and reviewed however, the results are so shocking and revolutionary that independent verification and confirmation are required before the conclusion, that neutrinos actually do travel faster than the speed of light, can be accepted.
About Septentrio Satellite Navigation
Septentrio Satellite Navigation NV designs, manufactures, markets and supports high-end OEM GNSS receivers for demanding professional navigation, positioning and timing applications. Septentrio has an international team of experts in all areas of satellite navigation receiver design and applications. For more information about Septentrio, please visit our website at www.septentrio.com.