Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243707
C. Hegarty
This paper provides an overview of Global Navigation Satellite System (GNSS) signals. Today, GNSS comprises two major constellations: (1) the United States' Global Positioning System (GPS), and (2) the Russian Federation's Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS). Two other major constellations are being deployed. Additionally, regional systems have been deployed or are planned. Whereas most GNSS timing receivers today rely only upon the legacy GPS signals, it is anticipated in the near future that multi-system receivers will become the norm. This paper describes the characteristics of each of the GNSS signals, and highlights the performance benefits that will be provided to the precise time and frequency community as the GNSS evolves.
{"title":"GNSS signals — An overview","authors":"C. Hegarty","doi":"10.1109/FCS.2012.6243707","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243707","url":null,"abstract":"This paper provides an overview of Global Navigation Satellite System (GNSS) signals. Today, GNSS comprises two major constellations: (1) the United States' Global Positioning System (GPS), and (2) the Russian Federation's Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS). Two other major constellations are being deployed. Additionally, regional systems have been deployed or are planned. Whereas most GNSS timing receivers today rely only upon the legacy GPS signals, it is anticipated in the near future that multi-system receivers will become the norm. This paper describes the characteristics of each of the GNSS signals, and highlights the performance benefits that will be provided to the precise time and frequency community as the GNSS evolves.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"12 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":"129487939","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.2012.6243644
Yanrong Xue, Xiaohui Li, Longxia Xu, Ye Ren
Combining with the principle of dual-satellite TDOA and FDOA in passive location system, a position differential method basing on dual-satellite TDOA and FDOA in passive location is put forward, which derives solution position of known and unknown radiation source by using conventional location algorithm method of TDOA and FDOA location, then position correction is achieved by subtracting the exact position and solution position of known radiation source to correct the solution position of unknown radiation source. Simulation results show that, according to similar Geometric Dilution of Precision(GDOP) principle, the known and unknown radiation source at a distance of several hundred kilometers are selected for differential, which can greatly improve location precision. This method develop positioning system of dual-satellite TDOA and FDOA, which has important value for improving its availability and the reliability of positioning result.
{"title":"Research on position differential method of dual-satellites TDOA and FDOA in passive location system","authors":"Yanrong Xue, Xiaohui Li, Longxia Xu, Ye Ren","doi":"10.1109/FCS.2012.6243644","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243644","url":null,"abstract":"Combining with the principle of dual-satellite TDOA and FDOA in passive location system, a position differential method basing on dual-satellite TDOA and FDOA in passive location is put forward, which derives solution position of known and unknown radiation source by using conventional location algorithm method of TDOA and FDOA location, then position correction is achieved by subtracting the exact position and solution position of known radiation source to correct the solution position of unknown radiation source. Simulation results show that, according to similar Geometric Dilution of Precision(GDOP) principle, the known and unknown radiation source at a distance of several hundred kilometers are selected for differential, which can greatly improve location precision. This method develop positioning system of dual-satellite TDOA and FDOA, which has important value for improving its availability and the reliability of positioning result.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"33 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":"130416678","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.2012.6243680
K. J. Hughes, A. Hati, Craig W. Nelson, David A. Howe
Frequency-stabilized lasers are routinely used in a variety of research and application areas relating to laser-cooled atoms. Important applications in the cold-atom regime include atomic time keeping, inertial navigation, gravitational sensing, and magnetometry. The number of applications based on frequency stabilized lasers is increasing and at the same time, there is a push to miniaturize devices base on these applications. As devices become smaller and more mobile, it will become increasingly important to be able to measure and understand the effects of vibration on the individual devices as a whole, as well as the frequency-stabilized laser subsystems. Here we present preliminary vibration studies of a lab-built laser system based on a monolithic semiconductor laser diode frequency stabilized to the D2 transition in 87Rb using FM saturated absorption spectroscopy.
{"title":"Vibrational analysis of stabilized lasers","authors":"K. J. Hughes, A. Hati, Craig W. Nelson, David A. Howe","doi":"10.1109/FCS.2012.6243680","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243680","url":null,"abstract":"Frequency-stabilized lasers are routinely used in a variety of research and application areas relating to laser-cooled atoms. Important applications in the cold-atom regime include atomic time keeping, inertial navigation, gravitational sensing, and magnetometry. The number of applications based on frequency stabilized lasers is increasing and at the same time, there is a push to miniaturize devices base on these applications. As devices become smaller and more mobile, it will become increasingly important to be able to measure and understand the effects of vibration on the individual devices as a whole, as well as the frequency-stabilized laser subsystems. Here we present preliminary vibration studies of a lab-built laser system based on a monolithic semiconductor laser diode frequency stabilized to the D2 transition in 87Rb using FM saturated absorption spectroscopy.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"17 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":"129220450","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.2012.6243695
T. Ma, Ji Wang, Jianke Du, Lili Yuan, Zhitian Zhang, Chao Zhang
The previous investigations showed that a local domain inversion takes place when bare LiNbO3 plates undergo heat treatment at temperatures higher than 1070°C. The LiNbO3 plates with an inversion layer have been used to fabricate piezoelectric bulk acoustic wave devices. The researches on the application of inversion layer piezoelectric devices mainly focused on high frequency ultrasonic transducers working on the thickness extensional mode. The research on inversion layer devices working on the thickness shear mode has not been reported. In this work, several experiments were done to investigate the characteristics of the inversion layer device working on the thickness shear mode. It is found that when the device works on the 2nd harmonic of the thickness shear mode under the role of the inversion layer, spurious modes decrease obviously. The mechanism of suppressing spurious modes through the inversion layer was analyzed. Therefore, bulk acoustic wave devices with an inversion layer working on the thickness shear mode have a good prospect in sensors and resonators.
{"title":"A novel thickness-shear mode resonator using a LiNbO3 plate with an inversion layer","authors":"T. Ma, Ji Wang, Jianke Du, Lili Yuan, Zhitian Zhang, Chao Zhang","doi":"10.1109/FCS.2012.6243695","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243695","url":null,"abstract":"The previous investigations showed that a local domain inversion takes place when bare LiNbO3 plates undergo heat treatment at temperatures higher than 1070°C. The LiNbO3 plates with an inversion layer have been used to fabricate piezoelectric bulk acoustic wave devices. The researches on the application of inversion layer piezoelectric devices mainly focused on high frequency ultrasonic transducers working on the thickness extensional mode. The research on inversion layer devices working on the thickness shear mode has not been reported. In this work, several experiments were done to investigate the characteristics of the inversion layer device working on the thickness shear mode. It is found that when the device works on the 2nd harmonic of the thickness shear mode under the role of the inversion layer, spurious modes decrease obviously. The mechanism of suppressing spurious modes through the inversion layer was analyzed. Therefore, bulk acoustic wave devices with an inversion layer working on the thickness shear mode have a good prospect in sensors and resonators.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"94 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":"126493141","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.2012.6243579
Du Zhi-jing, Zhan Shou-gang, L. Jie, Li Xiao-feng, Liu Dan-dan, Xue Wen-xiang
In this paper we report a laboratory prototype of pulsed optically pumped (POP) rubidium frequency standard. In POP operation the pumping, interrogation, and detection phases are separated in time, avoiding the coupling between microwave and optical coherence. The POP 87Rb vapor-cell frequency standard was studied experimentally based on the detection of free induction microwave signal or optical absorption signal. Ramsey fringes were obtained based on 87Rb in buffer gas, with FWHM of 65Hz and 150Hz for microwave and optical central Ramsey fringes respectively. The atomic quality factor was on the order of 108. With microwave detection, the achieved frequency stability was 1.2×10-12τ-1/2(τ=1~100s).
{"title":"The pulsed optically pumped Rb frequency standards in National Time Service Center","authors":"Du Zhi-jing, Zhan Shou-gang, L. Jie, Li Xiao-feng, Liu Dan-dan, Xue Wen-xiang","doi":"10.1109/FCS.2012.6243579","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243579","url":null,"abstract":"In this paper we report a laboratory prototype of pulsed optically pumped (POP) rubidium frequency standard. In POP operation the pumping, interrogation, and detection phases are separated in time, avoiding the coupling between microwave and optical coherence. The POP 87Rb vapor-cell frequency standard was studied experimentally based on the detection of free induction microwave signal or optical absorption signal. Ramsey fringes were obtained based on 87Rb in buffer gas, with FWHM of 65Hz and 150Hz for microwave and optical central Ramsey fringes respectively. The atomic quality factor was on the order of 108. With microwave detection, the achieved frequency stability was 1.2×10-12τ-1/2(τ=1~100s).","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"16 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":"126439591","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.2012.6243678
K. Fong, W. Pernice, H. Tang
In this report, we study the noise characteristics of the high quality factor nanomechanical resonators made of tensile-stressed stoichiometric silicon nitride. Quality factors (Q) of more than 2 million are measured at liquid helium temperature. With such high Q, the resonator noise performance is studied with high precision. We observe that while the amplitude noise agrees well with the thermomechanical noise, the phase noise is significantly higher than that. Such discrepancy is found to be due to the intrinsic resonance frequency fluctuation. We develop a mathematical model to describe the observed phenomenon and derive an expression relating the phase noise and the resonance frequency noise power spectral densities. From the phase noise measurement, we calculate the resonance frequency noise spectrum of the resonators and conclude that it has a kBT/f dependence.
{"title":"Observation of kBT/f frequency noise in ultrahigh Q silicon nitride nanomechanical resonators","authors":"K. Fong, W. Pernice, H. Tang","doi":"10.1109/FCS.2012.6243678","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243678","url":null,"abstract":"In this report, we study the noise characteristics of the high quality factor nanomechanical resonators made of tensile-stressed stoichiometric silicon nitride. Quality factors (Q) of more than 2 million are measured at liquid helium temperature. With such high Q, the resonator noise performance is studied with high precision. We observe that while the amplitude noise agrees well with the thermomechanical noise, the phase noise is significantly higher than that. Such discrepancy is found to be due to the intrinsic resonance frequency fluctuation. We develop a mathematical model to describe the observed phenomenon and derive an expression relating the phase noise and the resonance frequency noise power spectral densities. From the phase noise measurement, we calculate the resonance frequency noise spectrum of the resonators and conclude that it has a kBT/f dependence.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"102 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":"126012981","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.2012.6243648
A. Dobrogowski, M. Kasznia
This paper deals with the problem of the real-time analysis of synchronization signals. The methods of Maximum Time Interval Error computation performed in the real time for multi-channel measurement of time error are proposed and described.
{"title":"Some concepts of the real-time MTIE assessment for multi-channel time error measurement","authors":"A. Dobrogowski, M. Kasznia","doi":"10.1109/FCS.2012.6243648","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243648","url":null,"abstract":"This paper deals with the problem of the real-time analysis of synchronization signals. The methods of Maximum Time Interval Error computation performed in the real time for multi-channel measurement of time error are proposed and described.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"15 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":"122009777","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.2012.6243693
L. Yi, S. Taghavi-Larigani, E. Burt, R. Tjoelker
As part of an on-going effort to build a dual-isotope ion trap clock based on the 199Hg+ and 201Hg+ ground state hyperfine transitions, we continue to characterize the systematic sensitivities of the 201Hg+ 29.9GHz clock transition. Here we present an extension to the previous 201Hg+ collision shift measurement for helium[1] to other background gases. We also measured the collision shifts in the 199Hg+ 40.5GHz clock transition in the same physical system. We find that frequency sensitivities to collisions with background gas for the two isotopes agree within a factor of two. We will also discuss planned collision shift measurements with co-trapped 199Hg+ and 201Hg+, as an important step towards a dual-isotope atomic clock.
{"title":"Progress towards a dual-isotope trapped mercury ion atomic clock: Further studies of background gas collision shifts","authors":"L. Yi, S. Taghavi-Larigani, E. Burt, R. Tjoelker","doi":"10.1109/FCS.2012.6243693","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243693","url":null,"abstract":"As part of an on-going effort to build a dual-isotope ion trap clock based on the <sup>199</sup>Hg<sup>+</sup> and <sup>201</sup>Hg<sup>+</sup> ground state hyperfine transitions, we continue to characterize the systematic sensitivities of the <sup>201</sup>Hg<sup>+</sup> 29.9GHz clock transition. Here we present an extension to the previous <sup>201</sup>Hg<sup>+</sup> collision shift measurement for helium[1] to other background gases. We also measured the collision shifts in the <sup>199</sup>Hg<sup>+</sup> 40.5GHz clock transition in the same physical system. We find that frequency sensitivities to collisions with background gas for the two isotopes agree within a factor of two. We will also discuss planned collision shift measurements with co-trapped <sup>199</sup>Hg<sup>+</sup> and <sup>201</sup>Hg<sup>+</sup>, as an important step towards a dual-isotope atomic clock.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"6 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":"121631474","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.2012.6243656
G. Papin, R. Lévy, A. Bosseboeuf, F. Fabbri, F. Parrain, M. Malak, T. Bourouina, G. Lissorgues, P. Poulichet
Optical actuation and detection of MEMS resonators can improve the resolution of their motion detection compared to standard detection techniques (capacitive, piezoelectric). In this paper, a behavioral model of MEMS resonator with optical actuation and detection and the associated oscillator circuit are presented and used to determine its performances.
{"title":"Optical actuation and detection of MEMS resonators: Behavioral modeling and phase noise simulations","authors":"G. Papin, R. Lévy, A. Bosseboeuf, F. Fabbri, F. Parrain, M. Malak, T. Bourouina, G. Lissorgues, P. Poulichet","doi":"10.1109/FCS.2012.6243656","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243656","url":null,"abstract":"Optical actuation and detection of MEMS resonators can improve the resolution of their motion detection compared to standard detection techniques (capacitive, piezoelectric). In this paper, a behavioral model of MEMS resonator with optical actuation and detection and the associated oscillator circuit are presented and used to determine its performances.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"225 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":"132198757","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.2012.6243649
M. B. Reddy, S. Swarna, Priskala, M. Chandrashekar, C. Vinod, P. M. Dhruva, D. K. Singh
In recent times there is an increasing demand for the use of high frequency Oven Controlled Crystal Oscillators (OCXO) as a reference source for satellite communication payloads. OCXOs with reference frequency of 128MHz are designed & realized. OCXOs are proposed to be used in satellite communication payloads by Indian Space Research Organization (ISRO). The goal was to demonstrate the electrical performance & ruggedness of OCXO for Space application. The Main performance parameters achieved for Flight Model (FM) OCXO is summarized. Parameters of the Crystal used for this application to achieve optimum performance is also discussed. The Screening test of FM units have undergone through Stabilization Bake, Initial Stage Aging at 60°C, Thermal Shock, Operational Temp Test, Random vibration, Aging at 25°C, Radiographic inspection as per MIL standards. Thermo vacuum test is also carried out on few samples.
{"title":"High frequency OCXO for Space applications","authors":"M. B. Reddy, S. Swarna, Priskala, M. Chandrashekar, C. Vinod, P. M. Dhruva, D. K. Singh","doi":"10.1109/FCS.2012.6243649","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243649","url":null,"abstract":"In recent times there is an increasing demand for the use of high frequency Oven Controlled Crystal Oscillators (OCXO) as a reference source for satellite communication payloads. OCXOs with reference frequency of 128MHz are designed & realized. OCXOs are proposed to be used in satellite communication payloads by Indian Space Research Organization (ISRO). The goal was to demonstrate the electrical performance & ruggedness of OCXO for Space application. The Main performance parameters achieved for Flight Model (FM) OCXO is summarized. Parameters of the Crystal used for this application to achieve optimum performance is also discussed. The Screening test of FM units have undergone through Stabilization Bake, Initial Stage Aging at 60°C, Thermal Shock, Operational Temp Test, Random vibration, Aging at 25°C, Radiographic inspection as per MIL standards. Thermo vacuum test is also carried out on few samples.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"241 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":"133966895","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：