scholarly journals Analysis of highly accurate rain intensity measurements from a field test site

2010 ◽  
Vol 25 ◽  
pp. 37-44 ◽  
Author(s):  
L. G. Lanza ◽  
E. Vuerich ◽  
I. Gnecco
Keyword(s):  
Rainfall Intensity ◽  
Test Site ◽  
Quality Data ◽  
Rain Intensity ◽  
Data Set ◽  
High Quality Data ◽  
Operational Conditions ◽  
Rain Gauges ◽  
Intensity Measurements ◽  
Instrument Intercomparison

Abstract. In the course of the recent WMO international instrument intercomparison in the field and the associated specific laboratory tests, highly accurate rainfall intensity measurements have been collected and made available for scientific investigation. The resulting high quality data set (contemporary one-minute rainfall intensity data from 26 gauges based on various measuring principles) constitutes an important resource to provide insights into the expected behaviour of rain intensity gauges in operational conditions and further useful information for National Meteorological Services and other users. A few aspects of the analysis of one-minute resolution rain intensity measurements are discussed in this paper, focusing on the observed deviations from a calculated reference intensity based on four pit gauges. Results from both catching and non-catching type gauges are discussed in relation with suitable tolerance limits obtained as a combination of the estimated uncertainty of the reference intensity and the WMO accuracy limits for rainfall intensity measurements. It is shown that suitably post-processed weighing gauges and tipping-bucket rain gauges had acceptable performance, while none of the non-catching rain gauges agreed well with the reference.

scholarly journals Certified accuracy of rainfall data as a standard requirement in scientific investigations

2008 ◽  
Vol 16 ◽  
pp. 43-48 ◽  
Author(s):  
L. G. Lanza ◽  
L. Stagi
Keyword(s):  
Rainfall Intensity ◽  
Rain Gauge ◽  
Standard Requirement ◽  
Accuracy Requirement ◽  
Rain Gauges ◽  
Scientific Investigations ◽  
Intensity Measurements ◽  
Meteorological Observations ◽  
Instrument Intercomparison ◽  
Rain Data

Abstract. This paper elaborates on the rationale behind the proposed standard limits for the accuracy of rainfall intensity measurements obtained from tipping-bucket and other types of rain gauges. Indeed, based on experimental results obtained in the course of international instrument Intercomparison initiatives and specific laboratory tests, it is shown here that the accuracy of operational rain gauges can be reduced to the limits of ±1% after proper calibration and correction. This figure is proposed as a standard accuracy requirement for the use of rain data in scientific investigations. This limit is also proposed as the reference accuracy for operational rain gauge networks in order to comply with quality assurance systems in meteorological observations.

Test-site calibration and validation of airborne and ground-based TEM systems

Geophysics ◽  
2013 ◽  
Vol 78 (2) ◽  
pp. E95-E106 ◽  
Author(s):  
Nikolaj Foged ◽  
Esben Auken ◽  
Anders Vest Christiansen ◽  
Kurt Ingvard Sørensen
Keyword(s):  
Reference Model ◽  
Test Site ◽  
Positive Outcome ◽  
Quality Data ◽  
Data Set ◽  
High Quality Data ◽  
Reference Sections ◽  
Model Section ◽  
Time Domain Electromagnetic ◽  
Single Data

Validation and calibration of airborne and ground-based time-domain electromagnetic (TEM) systems are important to obtain high-quality data and thereby reliable and reproducible results. Validation and calibration become even more important when the TEM systems are to be used for low-anomaly groundwater and environmental applications. The recent extension of the Danish TEM test site has made it possible to perform detailed validation of airborne TEM systems and calibrate airborne TEM systems that cannot make hovering measurements. We evaluated the Danish TEM test site and used a test site calibration scheme recommended for ground-based as well as airborne TEM systems. Furthermore, we discovered an extended data set from the airborne TEM system, SkyTEM, from the test site, used for an extensive validation of the SkyTEM system. This validation included repeatability tests at different heights and comparisons with the reference sections obtained with ground-based measurements. The validation and comparison were performed directly on the inversion results and in data space, down to the single data gate values. The extensive validation of the SkyTEM system at the TEM test site revealed a very stable and reliable system. The data repeatability of the SkyTEM system at different heights and directions was, in general, well within the standard deviation (STD) of the data. The agreement between the ground-based reference model sections and the SkyTEM model section from different recording heights was very good. Likewise, the match between the ground-based reference data and the SkyTEM data was good and, in general, within 1.5 times the STD on the data. The positive outcome of the extensive validation also confirmed that data processing and modeling were performed at the highest standard.

scholarly journals Truthful Mechanism Design for Multiregion Mobile Crowdsensing

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yu Qiao ◽  
Jun Wu ◽  
Hao Cheng ◽  
Zilan Huang ◽  
Qiangqiang He ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Mechanism Design ◽  
Learning Systems ◽  
Quality Data ◽  
Weighted Mean ◽  
High Quality ◽  
Data Set ◽  
High Quality Data ◽  
Incentive Mechanisms ◽  
New Challenges

In the age of the development of artificial intelligence, we face the challenge on how to obtain high-quality data set for learning systems effectively and efficiently. Crowdsensing is a new powerful tool which will divide tasks between the data contributors to achieve an outcome cumulatively. However, it arouses several new challenges, such as incentivization. Incentive mechanisms are significant to the crowdsensing applications, since a good incentive mechanism will attract more workers to participate. However, existing mechanisms failed to consider situations where the crowdsourcer has to hire capacitated workers or workers from multiregions. We design two objectives for the proposed multiregion scenario, namely, weighted mean and maximin. The proposed mechanisms maximize the utility of services provided by a selected data contributor under both constraints approximately. Also, extensive simulations are conducted to verify the effectiveness of our proposed methods.

scholarly journals Oscillations in the Sun with SONG: Setting the scale for asteroseismic investigations

2019 ◽  
Vol 623 ◽  
pp. L9 ◽  
Author(s):  
M. Fredslund Andersen ◽  
P. Pallé ◽  
J. Jessen-Hansen ◽  
K. Wang ◽  
F. Grundahl ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Quality Data ◽  
Scaling Relations ◽  
The Sun ◽  
Average Amplitude ◽  
Echelle Spectrograph ◽  
High Quality ◽  
Data Set ◽  
High Quality Data ◽  
High Cadence

Context. We present the first high-cadence multiwavelength radial-velocity observations of the Sun-as-a-star, carried out during 57 consecutive days using the stellar échelle spectrograph at the Hertzsprung SONG Telescope operating at the Teide Observatory. Aims. Our aim was to produce a high-quality data set and reference values for the global helioseismic parameters νmax, ⊙ and Δν⊙ of the solar p-modes using the SONG instrument. The obtained data set or the inferred values should then be used when the scaling relations are applied to other stars showing solar-like oscillations observed with SONG or similar instruments. Methods. We used different approaches to analyse the power spectrum of the time series to determine νmax, ⊙: simple Gaussian fitting and heavy smoothing of the power spectrum. We determined Δν⊙ using the method of autocorrelation of the power spectrum. The amplitude per radial mode was determined using the method described in Kjeldsen et al. (2008, ApJ, 682, 1370). Results. We found the following values for the solar oscillations using the SONG spectrograph: νmax, ⊙ = 3141 ± 12 μHz, Δν⊙ = 134.98 ± 0.04 μHz, and an average amplitude of the strongest radial modes of 16.6 ± 0.4 cm s−1. These values are consistent with previous measurements with other techniques.

Evaluation of Measurement Errors of Tipping Bucket Rain Gauges

2020 ◽  
Author(s):  
Guangxu Jiang ◽  
Jiufu Liu ◽  
Xuegang Li ◽  
Hongwei Liu ◽  
Aimin Liao
Keyword(s):  
Measurement Error ◽  
Double Layer ◽  
Measurement Errors ◽  
Rainfall Intensity ◽  
Single Layer ◽  
Intensity Variation ◽  
Water Volume ◽  
Residual Water ◽  
Rain Intensity ◽  
Rain Gauges

<p>The observation accuracy of rainfall processes affects every aspects of the meteorological and hydrological affairs, which is widely monitored by various types of tipping bucket rain gauges（TBRs）because of the simple structure and reliable performance. The study of the measurement errors of TBRs is quite valuable and necessary for improving the rainfall data quality and evaluating the uncertainty of the research based on the dataset.</p><p>In this study, an artificial rainfall and monitor experiment system is designed with peristaltic pump, balances, recorder and controller for the accurate rainfall and the TBRs instrumental values record, based on which the error distribution and instrument stability were analyzed. Eight types of TBRs are chose for the error evaluation experiment, including five single-layer TBRs, three double-layer TBRs. For each TBRs, we observe its performance under 6 rain intensity (0.1-4mm/min) in turn. With regard to each rain intensity, when the simulated total rainfall reaches 10 mm, the experiment stops and records the data, then repeats the same experiment 6 times.</p><p>The result shows that the single-layer TBRs have a good linear relationship between the rainfall and the measurement error, and the double-layer TBRs has a significant regulating effect on the continuous heavy rain intensity, which can make the rain flow steadily down to the lower tipping bucket (metering tipping bucket) with a stable rain intensity to avoid the rain intensity variation influence on the measurement error. However, due to its high resolution of 0.1mm, it is greatly affected by the residual water volume of the tipper bucket.</p><p>According to the results, the single-layer TBRs can correct the actual rainfall measurement process according to the error ~ rainfall intensity curve. The double-layer TBRs can play an important role in the rainy day record, but the randomness of the residual in the tipping bucket needs to be further estimated. Because the proportion of the light rainfall intensity in most of the rainfall events are quite high according to the statistics, it is necessary to have lower measurement error under the light rainfall in the TBRs chosen and calibration process. It's a good idea to choose a combination of rain gauges(0.1mm&0.5mm) to improve the accuracy of rainfall and rainy day.</p>

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