Pub Date : 2014-04-03DOI: 10.1109/ISISS.2014.6782506
M. Larsen, M. Bulatowicz
Information on the Nuclear Magnetic Resonance Gyro under development by Northrop Grumman Corporation is presented. The basics of Operation are summarized, a review of the completed phases is presented, and the current state of development and progress in phase 4 is discussed. Many details have been left out for the sake of brevity, but the principles are still complete.
{"title":"Nuclear Magnetic Resonance Gyroscope: For DARPA's micro-technology for positioning, navigation and timing program","authors":"M. Larsen, M. Bulatowicz","doi":"10.1109/ISISS.2014.6782506","DOIUrl":"https://doi.org/10.1109/ISISS.2014.6782506","url":null,"abstract":"Information on the Nuclear Magnetic Resonance Gyro under development by Northrop Grumman Corporation is presented. The basics of Operation are summarized, a review of the completed phases is presented, and the current state of development and progress in phase 4 is discussed. Many details have been left out for the sake of brevity, but the principles are still complete.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121697899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243701
A. Poddar, U. Rohde
This paper reports a methodology of combining differential-phase-shift-injection-locking (DPSIL) with mode-coupled-delay-feedback (MCDF) techniques to shave the size, cost, and phase noise from Crystal oscillator circuits. An example of 100 MHz, 125 MHz and 155 MHz ovenized crystal oscillator (OCXO) is demonstrated for the validation of the novel approach, which holds good for both fundamental and higher order overtone mode high frequency crystal oscillator circuits.
{"title":"Techniques minimize the phase noise in crystal oscillator circuits","authors":"A. Poddar, U. Rohde","doi":"10.1109/FCS.2012.6243701","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243701","url":null,"abstract":"This paper reports a methodology of combining differential-phase-shift-injection-locking (DPSIL) with mode-coupled-delay-feedback (MCDF) techniques to shave the size, cost, and phase noise from Crystal oscillator circuits. An example of 100 MHz, 125 MHz and 155 MHz ovenized crystal oscillator (OCXO) is demonstrated for the validation of the novel approach, which holds good for both fundamental and higher order overtone mode high frequency crystal oscillator circuits.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115502008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243603
Liang Kun, Li Tianchu, W. Weibo, Ning Dayu, Zhang Aimin, Fang Fang, W. Tianyi
At NIM, one GPS carrier phase processing method exclusively for time and frequency transfer, GPSTFP, was developed. Using the method, we implemented the CCD and long baseline time and frequency transfer experiments for performance verification. We can acquire the good agreement among P3 results, GPSTFP results, and the ones by the professional GPS processing software. From one day data, the difference between the mean values of P3 and GPSTFP results was less than 0.5 ns and the time stability from the CCD experiment is about 100 ps.
{"title":"GPS carrier phase time transfer using a modified solution model","authors":"Liang Kun, Li Tianchu, W. Weibo, Ning Dayu, Zhang Aimin, Fang Fang, W. Tianyi","doi":"10.1109/FCS.2012.6243603","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243603","url":null,"abstract":"At NIM, one GPS carrier phase processing method exclusively for time and frequency transfer, GPSTFP, was developed. Using the method, we implemented the CCD and long baseline time and frequency transfer experiments for performance verification. We can acquire the good agreement among P3 results, GPSTFP results, and the ones by the professional GPS processing software. From one day data, the difference between the mean values of P3 and GPSTFP results was less than 0.5 ns and the time stability from the CCD experiment is about 100 ps.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123123015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243623
Wu Wenjun, Li Zhigang, Yang Xuhai, Ren Xiaoqian, Chen Liang, Lei Hui, Feng Chugang
It is almost reciprocity of the Two-way satellite time and frequency transfer(TWSTFT) communication links. The path delays are almost canceled out due to the symmetry. It is the advantage of TWSTFT. But as the technology development, the higher accurate is required for time comparison. The incomplete reciprocity must be studied in detail for TWSTFT. Satellite motion is a kind of the incomplete reciprocity and can result that the uplink geometry paths aren't equal to the downlink geometry paths. Satellite motion's correction depends on the satellite velocity and time difference between the signal from two stations arrive at the satellite.
{"title":"A new method for satellite motion correction in TWSTFT","authors":"Wu Wenjun, Li Zhigang, Yang Xuhai, Ren Xiaoqian, Chen Liang, Lei Hui, Feng Chugang","doi":"10.1109/FCS.2012.6243623","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243623","url":null,"abstract":"It is almost reciprocity of the Two-way satellite time and frequency transfer(TWSTFT) communication links. The path delays are almost canceled out due to the symmetry. It is the advantage of TWSTFT. But as the technology development, the higher accurate is required for time comparison. The incomplete reciprocity must be studied in detail for TWSTFT. Satellite motion is a kind of the incomplete reciprocity and can result that the uplink geometry paths aren't equal to the downlink geometry paths. Satellite motion's correction depends on the satellite velocity and time difference between the signal from two stations arrive at the satellite.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"214 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115831176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243577
M. E. Frerking
TCXO's first became available in the early 1960's. The accuracy was limited to about 0.5 ppm by the degree to which the analog thermistor networks could track the crystal temperature curve. The advent of digital compensation eliminated the curve fitting problem, but accuracy was still limited to about 0.1 ppm due to retrace problems in the oscillator. Making the oscillator pullable also made it less stable. The effect was reduced by synthesizing the output frequency in some way rather than pulling the crystal to frequency. This also allowed the use of SC-cut crystals and improved the accuracy to a few parts in 108. Dual mode temperature sensing improved thermal tracking, but hysteresis effects in the crystal still limited the accuracy. Implementation of a dual mode oscillator presents some challenges that, depending on the circuit, may result in additional hysteresis being introduced by circuit elements.
{"title":"Sequenced mode TCXO","authors":"M. E. Frerking","doi":"10.1109/FCS.2012.6243577","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243577","url":null,"abstract":"TCXO's first became available in the early 1960's. The accuracy was limited to about 0.5 ppm by the degree to which the analog thermistor networks could track the crystal temperature curve. The advent of digital compensation eliminated the curve fitting problem, but accuracy was still limited to about 0.1 ppm due to retrace problems in the oscillator. Making the oscillator pullable also made it less stable. The effect was reduced by synthesizing the output frequency in some way rather than pulling the crystal to frequency. This also allowed the use of SC-cut crystals and improved the accuracy to a few parts in 108. Dual mode temperature sensing improved thermal tracking, but hysteresis effects in the crystal still limited the accuracy. Implementation of a dual mode oscillator presents some challenges that, depending on the circuit, may result in additional hysteresis being introduced by circuit elements.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121343411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243667
Steven Eric Peil, S. Crane, J. Hanssen, T. Swanson, C. Ekstrom
Four rubidium fountains have been in operation for the past 1.2 years at USNO. Individual fountain performance, applications to timekeeping and to tests of Local Position Invariance are presented.
{"title":"An ensemble of atomic fountains","authors":"Steven Eric Peil, S. Crane, J. Hanssen, T. Swanson, C. Ekstrom","doi":"10.1109/FCS.2012.6243667","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243667","url":null,"abstract":"Four rubidium fountains have been in operation for the past 1.2 years at USNO. Individual fountain performance, applications to timekeeping and to tests of Local Position Invariance are presented.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124901576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243748
Zhi-jun Chen, Peng Ruan, Xin Huang, Dafeng Fu, Mengyang Wang
Acoustic Plate Mode Wave (APM) device is suitable for liquid-phase measurement. The appearance of liquid loading would lead to the energy leakage of APM and the reasons are various. According to acoustic wave propagation theory in the layered medium, this paper establishes the APM analysis model with liquid loading. Using non-viscous liquid, conductive liquid and viscous liquid as examples, by numerical simulations of general APM, sagittal APM and shear-horizontal APM, the APM energy leakage with liquid loading is researched, and the reasons are concluded. Furthermore, the two-dimensional analysis model of leaky APM is established by adding attenuation factor in the expressions of acoustic field components. The leaky APM propagation velocity and attenuation factor are obtained by the method of “surface effective permittivity rough-searching” added by “boundary conditions coefficient determinant refined-searching. The APM devices are designed and tested. The experimental results are in agreement with the numerical simulations.
{"title":"Energy leakage and attenuation analysis of APM with liquid loading","authors":"Zhi-jun Chen, Peng Ruan, Xin Huang, Dafeng Fu, Mengyang Wang","doi":"10.1109/FCS.2012.6243748","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243748","url":null,"abstract":"Acoustic Plate Mode Wave (APM) device is suitable for liquid-phase measurement. The appearance of liquid loading would lead to the energy leakage of APM and the reasons are various. According to acoustic wave propagation theory in the layered medium, this paper establishes the APM analysis model with liquid loading. Using non-viscous liquid, conductive liquid and viscous liquid as examples, by numerical simulations of general APM, sagittal APM and shear-horizontal APM, the APM energy leakage with liquid loading is researched, and the reasons are concluded. Furthermore, the two-dimensional analysis model of leaky APM is established by adding attenuation factor in the expressions of acoustic field components. The leaky APM propagation velocity and attenuation factor are obtained by the method of “surface effective permittivity rough-searching” added by “boundary conditions coefficient determinant refined-searching. The APM devices are designed and tested. The experimental results are in agreement with the numerical simulations.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125816956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243730
A. Hines, D. Y. Tucker, J. Hines, J. Castro, A. Abedi
Direct Sequence Spread Spectrum (DSSS) codes have a variety of applications, including implementing code diversity in wireless surface acoustic wave (SAW) multi-sensor systems. Such systems generally suffer from code collision problems, necessitating complex post-processing to avoid negatively impacting sensor calibration and system accuracy. Thus, development of groups of codes that exhibit very low cross-correlation is desirable to implement code diversity in passive wireless sensor systems. This paper discusses generation and analysis of Gold codes, a know class of codes with desirable cross-correlation properties. A logical criteria-based method for the `exhaustive' analysis of codes of a given length is also presented, applying a selected set of screening techniques to rapidly evaluate all possible candidate codes to a sufficient degree. Using this technique, sets of codes can be found that perform well in asynchronous correlation-based wireless sensor systems, reducing the need for complex post-processing.
{"title":"Techniques for optimal DSSS code selection for SAW multi-sensor systems","authors":"A. Hines, D. Y. Tucker, J. Hines, J. Castro, A. Abedi","doi":"10.1109/FCS.2012.6243730","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243730","url":null,"abstract":"Direct Sequence Spread Spectrum (DSSS) codes have a variety of applications, including implementing code diversity in wireless surface acoustic wave (SAW) multi-sensor systems. Such systems generally suffer from code collision problems, necessitating complex post-processing to avoid negatively impacting sensor calibration and system accuracy. Thus, development of groups of codes that exhibit very low cross-correlation is desirable to implement code diversity in passive wireless sensor systems. This paper discusses generation and analysis of Gold codes, a know class of codes with desirable cross-correlation properties. A logical criteria-based method for the `exhaustive' analysis of codes of a given length is also presented, applying a selected set of screening techniques to rapidly evaluate all possible candidate codes to a sufficient degree. Using this technique, sets of codes can be found that perform well in asynchronous correlation-based wireless sensor systems, reducing the need for complex post-processing.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"160 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116742116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243653
T. Mehlstaubler, K. Pyka, Jonas Keller, Norbert Herschbach, D. Meier, Kristijan Kuhlmann, Maksim Okhapkin, Stepan Ignatovich
We present the status of our new experiment to lasercool linear chains of 172Yb+ and 115In+ ions for an optical clock based on the 1S0-3P0 transition in 115In+. We successfully have trapped and laser-cooled Coulomb crystals of 172Yb+ ions in our new scalable ion trap that are used to characterize the trap and to sympathetically cool 115In+ ions. We could demonstrate an area of more than 65 μm, where the fractional frequency shifts due to time dilation are below 10-18 for both ions.
{"title":"Minimizing time-dilation in ion traps — Towards an optical clock with Coulomb crystals","authors":"T. Mehlstaubler, K. Pyka, Jonas Keller, Norbert Herschbach, D. Meier, Kristijan Kuhlmann, Maksim Okhapkin, Stepan Ignatovich","doi":"10.1109/FCS.2012.6243653","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243653","url":null,"abstract":"We present the status of our new experiment to lasercool linear chains of <sup>172</sup>Yb<sup>+</sup> and <sup>115</sup>In<sup>+</sup> ions for an optical clock based on the <sup>1</sup>S<sub>0</sub>-<sup>3</sup>P<sub>0</sub> transition in <sup>115</sup>In<sup>+</sup>. We successfully have trapped and laser-cooled Coulomb crystals of <sup>172</sup>Yb<sup>+</sup> ions in our new scalable ion trap that are used to characterize the trap and to sympathetically cool <sup>115</sup>In<sup>+</sup> ions. We could demonstrate an area of more than 65 μm, where the fractional frequency shifts due to time dilation are below 10<sup>-18</sup> for both ions.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117024074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243652
R. Le Targat, L. Lorini, M. Gurov, M. Zawada, R. Gartman, B. Nagórny, P. Lemonde, J. Lodewyck
Two optical lattice clocks operated on the transition 1S0-3P0 of the 87Sr atom are now operational at the LNE-SYRTE laboratory, their comparison aims at demonstrating that no systematic effect has been overlooked in their respective accuracy budgets. In this proceeding we focus only on trapping effects, we discuss technical aspects of the calibration of the lattice induced light shifts, and we show the observation of the second order light shift. Data resulting from the comparisons are reported and discussed.
{"title":"Comparison of two Strontium optical lattice clocks in agreement at the 10−16 level","authors":"R. Le Targat, L. Lorini, M. Gurov, M. Zawada, R. Gartman, B. Nagórny, P. Lemonde, J. Lodewyck","doi":"10.1109/FCS.2012.6243652","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243652","url":null,"abstract":"Two optical lattice clocks operated on the transition 1S0-3P0 of the 87Sr atom are now operational at the LNE-SYRTE laboratory, their comparison aims at demonstrating that no systematic effect has been overlooked in their respective accuracy budgets. In this proceeding we focus only on trapping effects, we discuss technical aspects of the calibration of the lattice induced light shifts, and we show the observation of the second order light shift. Data resulting from the comparisons are reported and discussed.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128732235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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