Statistics of atomic frequency standards

Allan, David W.

doi:10.1109/proc.1966.4634

Cited by 2,227 publications

(1,132 citation statements)

References 5 publications

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“…The Allan variance (AVAR) provides magnitude versus averaging time which in the form of a 2D log-log plot allows identification of the different noise types by the slopes of the different plot regions [2]. In case of the dynamic Allan variance (DAVAR) that was developed for the characterization of the space clock behavior [3] the observation interval τ and a given time t, the Allan variance σ A of the sensor output signal marked as x has to * corresponding author; e-mail: katarina.draganova@tuke.sk be considered and the DAVAR can be calculated as…”

Section: Theorymentioning

confidence: 99%

Non-Stationary Noise Analysis of Magnetic Sensors using Allan Variance

et al. 2017

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The presented paper describes methodology for the non-stationary noise analysis of the magnetic sensors' data using the dynamic Allan variance. The methodology was developed for the characterization of clock behavior. In the article the theory is applied for the magnetic sensors noise analysis and verified by the simulations and experiments. Results of the data analysis are graphically presented and statistically evaluated and prove the correctness of the initial hypothesis and confirm suitability of the dynamic Allan variance approach for magnetic sensors with the non-stationary noise behavior.

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Section: Theorymentioning

confidence: 99%

Non-Stationary Noise Analysis of Magnetic Sensors using Allan Variance

et al. 2017

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“…The precision of concentration measurements should be at least a few parts per thousand of the ambient mixing ratio., which is approximately 4 ppb for a mixing ratio of approximately 1800 ppb (outside air) in the case of CH 4 (Kroon et al, 2007). Both maximum system stability and precision can be determined using the Allan variance (Allan, 1966;Werle et al, 1993;Nelson et al, 2004;Kroon et al, 2007). The Allan variance (σ 2 A ), as a function of integration time T, is the average of the sample variance of two adjacent averages of time series of data and is described by Eq.…”

Section: Assessment Of Instrument Stability Precision and Accuracymentioning

confidence: 99%

“…In this equation A is an average of the CH 4 concentration, k is the number of elements in subgroup x, s is the subgroup number, l is the sample-number in the subgroup, and m the number of independent measurements. It is assumed that data are collected over a constant data interval t, therefore the integration time T =k t (Allan, 1966;Werle et al, 1993;Nelson et al, 2004). The Allan variance decreases when random noise dominates over drift effects.…”

Section: Assessment Of Instrument Stability Precision and Accuracymentioning

confidence: 99%

A compact and stable eddy covariance set-up for methane measurements using off-axis integrated cavity output spectroscopy

et al. 2008

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Abstract.A Fast Methane Analyzer (FMA) is assessed for its applicability in a closed path eddy covariance field set-up in a peat meadow. The FMA uses off-axis integrated cavity output spectroscopy combined with a highly specific narrow band laser for the detection of CH 4 and strongly reflective mirrors to obtain a laser path length of 2-20×10 3 m. Statistical testing and a calibration experiment showed high precision (7.8×10 −3 ppb) and accuracy (<0.30%) of the instrument, while no drift was observed. The instrument response time was determined to be 0.10 s. In the field set-up, the FMA is attached to a scroll pump and combined with a 3-axis ultrasonic anemometer and an open path infrared gas analyzer for measurements of carbon dioxide and water vapour. The power-spectra and co-spectra of the instruments were satisfactory for 10 Hz sampling rates.Due to erroneous measurements, spikes and periods of low turbulence the data series consisted for 26% of gaps. Observed CH 4 fluxes consisted mainly of emission, showed a diurnal cycle, but were rather variable over. The average CH 4 emission was 29.7 nmol m −2 s −1 , while the typical maximum CH 4 emission was approximately 80.0 nmol m −2 s −1 and the typical minimum flux was approximately 0.0 nmol m −2 s −1 . The correspondence of the measurements with flux chamber measurements in the footprint was good and the observed CH 4 emission rates were comparable with eddy covariance CH 4 measurements in other peat areas.Additionally, three measurement techniques with lower sampling frequencies were simulated, which might give the possibility to measure CH 4 fluxes without an external pump and save energy. Disjunct eddy covariance appeared to be the most reliable substitute for 10 Hz eddy covariance, while relaxed eddy accumulation gave reliable estimates of the fluxes over periods in the order of days or weeks.

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“…[29] The radiometric requirements for the Cassini GWE were originally derived from requirements expressed in terms of the Allan Standard Deviation (ASD) [Allan, 1966] of the atmospheric path delay measurement error.…”

Section: Stability Estimates From Side-by-side Datamentioning

confidence: 99%

Design and performance of a high‐stability water vapor radiometer

Tanner

Riley

2003

Radio Science

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[1] The design of two new high-stability microwave water vapor radiometers is presented along with a performance evaluation. The radiometers operate next to a spacecraft tracking station at NASA's Goldstone facility in California, where they will be used to calibrate tropospheric path delay fluctuations during an upcoming gravity-wave search experiment (GWE) involving the Cassini spacecraft. Observing frequencies of the radiometers are 22.2, 23.8, and 31.4 GHz, and the antenna beam width is 1°. The instruments are room temperature Dicke radiometers with additive noise injection for gain calibration. Design highlights include: (1) a practical temperature control system capable of stabilizing the entire receiver to a few millikelvin from day to night; (2) redundant noise diode injection circuits with 30 ppm RF power stability; and (3) a voice coil actuated waveguide vane attenuator which is used as a high-performance Dicke switch. Performance of the radiometers is evaluated from intercomparisons of the two radiometers and from continuous tip curve calibrations spanning nearly 1 year. Structure function analysis of the intercomparison data indicates that the brightness temperature stability of these radiometers is better than 0.01 K on 1000-10,000 s timescales. Analysis of tip curve calibrations indicates RMS errors of $0.05 K on 30-day timescales and 0.15 K on 1-year timescales.

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Statistics of atomic frequency standards

Abstract: A theoretical development is presented which results in a relationship between the expectation value of the standard deviation of the frequency fluctuations for any finite number of data

Cited by 2,227 publications

References 5 publications

Non-Stationary Noise Analysis of Magnetic Sensors using Allan Variance

Non-Stationary Noise Analysis of Magnetic Sensors using Allan Variance

A compact and stable eddy covariance set-up for methane measurements using off-axis integrated cavity output spectroscopy

Design and performance of a high‐stability water vapor radiometer

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