Neutrinos travelling faster than the speed of light? This unimaginable concept has become a hotly debated topic among physicists worldwide after the international OPERA experiment using a Global Navigation Satellite Systems (GNSS) receiver demonstrated it could be possible. This precise timing receiver was developed with the help of ESA´s Advanced Research in Telecommunications Systems (ARTES) programme.
An ESA project called Research and Development of Next-Generation GNSS Receivers has been dedicated to the enhancement and further development of Belgian-based company Septentrio’s precise PolaRx2eTR timing receivers. These receivers are designed for the professional market.
During the ARTES project, six product developments were completed to strengthen the competitive position of existing products and develop new products. Especially important was the implementation of the new baseband application-specific integrated circuits (ASIC).Three new products were launched commercially as a result of this contract.
GNSS receivers are not only capable of providing positioning information, they also provide very precise timing information. A 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. According to Septentrio, specialised circuitry in its 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 synchronise atomic clocks around the world and also used to synchronise the time bases at the European Organization for Nuclear Research (CERN) and Gran Sasso National Laboratory in Italy (LNGS) in the OPERA experiment. PolaRx2eTR receivers at both CERN and LNGS compare their local clocks to the clocks of the GNSS satellites commonly visible from both sites simultaneously. This allows researchers to synchronise the time at both laboratories to an accuracy of a couple of nanoseconds, the level needed to measure precisely the neutrino transit times.
“GNSS technology would not be possible without the application of Einstein’s theories in various ways," said Peter Grognard, managing director of Septentrio. “It is remarkable to experience that this same technology has now been used to test and challenge these fundamental physical principles.”
Septentrio began working with ESA in 2003 to develop new products and enhance its existing product line to increase Septentrio’s share in the professional GNSS receiver market. With the support of ARTES, Septentrio has been able to solidify its role as a leading European manufacturer of professional GNSS receivers.
“The objectives of ESA’s ARTES programme include providing support to European-based companies to ensure they can compete in the worldwide marketplace,” says Michele Le Saux, Head of the ESA Telecom Ground Segment Products section. “It is rewarding to see such companies succeed within the space industry.”