Smart substation precise time research and analysis

I analyse the role of simultaneity in relativistic rotation by building incrementally on its role in simpler scenarios. Historically, rotation has been analysed in 1 + 1 dimensions; but my stance is that a 2 + 1 -dimensional treatment is necessary. This treatment requires a discussion of what constitutes a frame, how coordinate choices differ from frame choices, and how poor coordinates can be misleading. I determine how precisely we are able to define a meaningful time coordinate on a gravity-free rotating Earth, and discuss complications due to gravity on our real Earth. I end with a critique of several statements made in relativistic precision-timing literature, that I maintain contradict the tenets of relativity. Those statements tend to be made in the context of satellite-based navigation; but they are independent of that technology, and hence are not validated by its success. I suggest that if relativistic precision-timing adheres to such analyses, our civilian timing is likely to suffer in the near future as clocks become ever more precise.

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Smart Substation Monitoring and Control

2021 7th International Conference on Advanced Computing and Communication Systems (ICACCS) ◽

10.1109/icaccs51430.2021.9442002 ◽

2021 ◽

Author(s):

N Loganathan ◽

J Prasanth ◽

R Shankara Saravanan ◽

V Jayasuriya ◽

S Karthikeyan

Keyword(s):

Monitoring And Control ◽

And Control ◽

Smart Substation

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Traceable time comparisons between Precise Time Protocol devices

CPEM 2010 ◽

10.1109/cpem.2010.5544543 ◽

2010 ◽

Author(s):

Te-Kwei Wang ◽

Fan-Ren Chang ◽

Shinn-Yan Lin

Keyword(s):

Precise Time

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Modeling and Analysis of BDS-2 and BDS-3 Combined Precise Time and Frequency Transfer Considering Stochastic Models of Inter-System Bias

Remote Sensing ◽

10.3390/rs13040793 ◽

2021 ◽

Vol 13 (4) ◽

pp. 793

Author(s):

Guoqiang Jiao ◽

Shuli Song ◽

Qinming Chen ◽

Chao Huang ◽

Ke Su ◽

...

Keyword(s):

Stochastic Models ◽

Satellite System ◽

Modeling And Analysis ◽

System Bias ◽

Frequency Transfer ◽

Global Navigation ◽

The Difference ◽

The Stability ◽

Global Navigation Satellite ◽

Precise Time

BeiDou global navigation satellite system (BDS) began to provide positioning, navigation, and timing (PNT) services to global users officially on 31 July, 2020. BDS constellations consist of regional (BDS-2) and global navigation satellites (BDS-3). Due to the difference of modulations and characteristics for the BDS-2 and BDS-3 default civil service signals (B1I/B3I) and the increase of new signals (B1C/B2a) for BDS-3, a systemically bias exists in the receiver-end when receiving and processing BDS-2 and BDS-3 signals, which leads to the inter-system bias (ISB) between BDS-2 and BDS-3 on the receiver side. To fully utilize BDS, the BDS-2 and BDS-3 combined precise time and frequency transfer are investigated considering the effect of the ISB. Four kinds of ISB stochastic models are presented, which are ignoring ISB (ISBNO), estimating ISB as random constant (ISBCV), random walk process (ISBRW), and white noise process (ISBWN). The results demonstrate that the datum of receiver clock offsets can be unified and the ISB deduced datum confusion can be avoided by estimating the ISB. The ISBCV and ISBRW models are superior to ISBWN. For the BDS-2 and BDS-3 combined precise time and frequency transfer using ISBNO, ISBCV, ISBRW, and ISBWN, the stability of clock differences of old signals can be enhanced by 20.18%, 23.89%, 23.96%, and 11.46% over BDS-2-only, respectively. For new signals, the enhancements are −50.77%, 20.22%, 17.53%, and −3.69%, respectively. Moreover, ISBCV and ISBRW models have the better frequency transfer stability. Consequently, we recommended the optimal ISBCV or suboptimal ISBRW model for BDS-2 and BDS-3 combined precise time and frequency transfer when processing the old as well as the new signals.

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