TY - GEN

T1 - GETTING THERE MORE SAFELY

T2 - Better GNSS Navigation and Spoofing Detection with Chip-Scale Atomic Clocks

AU - Krawinkel, Thomas

AU - Schön, Steffen

PY - 2016/10

Y1 - 2016/10

N2 - The recent development of chip-scale atomic clocks (CSACs) offers the required frequency stability and accuracy, and opens up the possibility of using atomic clocks in real kinematic GNSS applications without any severe restrictions regarding power supply or environmental influences on the clocks. A real kinematic experiment was carried out with two chip-scale atomic clocks, and typical code-based GPS navigation solutions were computed. It was shown that the precision of the up-coordinate time series are improved by up to 58 percent, depending on the clock in use. Furthermore, internal and external reliability were significantly enhanced. Additionally, it was shown that the algorithm is capable of coasting through periods of partial satellite outages with only three satellites in view. Finally, the benefits of an atomic clock in spoofing detection was investigated. The approach, based on a Kalman filter and a hypothesis test, enhances the detectability of a spoofer when using a CSAC instead of the receiver's internal oscillator, especially in the case of small signal delays injected by the spoofing device, which helps to identify a sophisticated spoofer very quickly. The receiver clock parameter absorbs signal delays common to all simultaneous line-of-sight signals whether these delays represent the physical clock or any other common delay. Thus, it is especially vulnerable to delays caused by jammers or spoofers. If the clock behavior is predictable, information about jamming or spoofing can be retrieved, and thus the integrity of the positioning solution can be improved.

AB - The recent development of chip-scale atomic clocks (CSACs) offers the required frequency stability and accuracy, and opens up the possibility of using atomic clocks in real kinematic GNSS applications without any severe restrictions regarding power supply or environmental influences on the clocks. A real kinematic experiment was carried out with two chip-scale atomic clocks, and typical code-based GPS navigation solutions were computed. It was shown that the precision of the up-coordinate time series are improved by up to 58 percent, depending on the clock in use. Furthermore, internal and external reliability were significantly enhanced. Additionally, it was shown that the algorithm is capable of coasting through periods of partial satellite outages with only three satellites in view. Finally, the benefits of an atomic clock in spoofing detection was investigated. The approach, based on a Kalman filter and a hypothesis test, enhances the detectability of a spoofer when using a CSAC instead of the receiver's internal oscillator, especially in the case of small signal delays injected by the spoofing device, which helps to identify a sophisticated spoofer very quickly. The receiver clock parameter absorbs signal delays common to all simultaneous line-of-sight signals whether these delays represent the physical clock or any other common delay. Thus, it is especially vulnerable to delays caused by jammers or spoofers. If the clock behavior is predictable, information about jamming or spoofing can be retrieved, and thus the integrity of the positioning solution can be improved.

UR - http://www.scopus.com/inward/record.url?scp=85017596511&partnerID=8YFLogxK

M3 - Contribution in non-scientific journal

AN - SCOPUS:85017596511

VL - 27

SP - 50

EP - 55

JO - GPS World

JF - GPS World

SN - 1048-5104

ER -