scholarly journals Performance of post-processing algorithms for rainfall intensity measurements of tipping-bucket rain gauges

2016 ◽  
Author(s):  
Mattia Stagnaro ◽  
Matteo Colli ◽  
Luca Giovanni Lanza ◽  
Pak Wai Chan
Keyword(s):  
Time Resolution ◽  
Rainfall Intensity ◽  
Single Layer ◽  
Time Algorithm ◽  
Post Processing ◽  
Sampling Errors ◽  
Rain Gauges ◽  
Intensity Measurements ◽  
Processing Algorithms ◽  
Rain Events

Abstract. A number of rain events recorded from May to September 2013 at the Hong Kong International Airport (HKIA) have been selected to investigate the performance of post-processing algorithms used to calculate the Rainfall Intensity (RI) from Tipping-Bucket Rain Gauges (TBRGs). We assumed a drop counter catching-type gauge as a working reference and compared rainfall intensity measurements with two calibrated TBRGs operated at a time resolution of 1 min. The two TBRGs differ in their internal mechanics, one being a traditional single-layer dual-bucket assembly, while the other has two layers of buckets. The drop counter gauge operates at a time resolution of 10 s, while the time of tipping is recorded for the two TBRGs. The post-processing algorithms employed for the two TBRGs are based on the assumption that the tip volume is uniformly distributed over the inter-tip period. A series of data of an ideal TBRG is reconstructed using the virtual time of tipping derived from the drop counter data. From the comparison between the ideal gauge and the measurements from the two real TBRGs the performance of different post-processing and correction algorithms are statistically evaluated over the set of recorded rain events. The improvement obtained by adopting the inter-tip time algorithm in the calculation of the RI is confirmed. However, by comparing the performance of the real and ideal TBRGs, the beneficial effect of the inter-tip algorithm is shown to be relevant for the mid-low range of rainfall intensity values (where the sampling errors prevail), while its role vanishes with increasing the RI, in the range where the mechanical errors prevail.

scholarly journals Performance of post-processing algorithms for rainfall intensity using measurements from tipping-bucket rain gauges

2016 ◽  
Vol 9 (12) ◽  
pp. 5699-5706 ◽  
Author(s):  
Mattia Stagnaro ◽  
Matteo Colli ◽  
Luca Giovanni Lanza ◽  
Pak Wai Chan
Keyword(s):  
Time Resolution ◽  
Rainfall Intensity ◽  
Single Layer ◽  
Time Algorithm ◽  
Post Processing ◽  
Sampling Errors ◽  
Rain Gauges ◽  
Virtual Time ◽  
Processing Algorithms ◽  
Rain Events

Abstract. Eight rainfall events recorded from May to September 2013 at Hong Kong International Airport (HKIA) have been selected to investigate the performance of post-processing algorithms used to calculate the rainfall intensity (RI) from tipping-bucket rain gauges (TBRGs). We assumed a drop-counter catching-type gauge as a working reference and compared rainfall intensity measurements with two calibrated TBRGs operated at a time resolution of 1 min. The two TBRGs differ in their internal mechanics, one being a traditional single-layer dual-bucket assembly, while the other has two layers of buckets. The drop-counter gauge operates at a time resolution of 10 s, while the time of tipping is recorded for the two TBRGs. The post-processing algorithms employed for the two TBRGs are based on the assumption that the tip volume is uniformly distributed over the inter-tip period. A series of data of an ideal TBRG is reconstructed using the virtual time of tipping derived from the drop-counter data. From the comparison between the ideal gauge and the measurements from the two real TBRGs, the performances of different post-processing and correction algorithms are statistically evaluated over the set of recorded rain events. The improvement obtained by adopting the inter-tip time algorithm in the calculation of the RI is confirmed. However, by comparing the performance of the real and ideal TBRGs, the beneficial effect of the inter-tip algorithm is shown to be relevant for the mid–low range (6–50 mmh−1) of rainfall intensity values (where the sampling errors prevail), while its role vanishes with increasing RI in the range where the mechanical errors prevail.

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>

Measurement properties of tipping bucket rain gauges and their influence on urban runoff simulation

1997 ◽  
Vol 36 (8-9) ◽  
pp. 7-12 ◽  
Author(s):  
R. Fankhauser
Keyword(s):  
Time Resolution ◽  
Rainfall Intensity ◽  
Depth Resolution ◽  
Urban Hydrology ◽  
Data Series ◽  
Runoff Simulation ◽  
Rainfall Events ◽  
Rain Gauges ◽  
Rainfall Depth ◽  
Bucket Size

Tipping bucket rain gauges (TBR) have become the most common device for measuring rainfall intensity in urban hydrology. Due to the measurement principle, the time resolution depends on rainfall intensity and bucket size. The present study investigated the influence of calibration uncertainties and bucket size on the accuracy of rainfall measurement and runoff simulation. Synthetic rainfall events with a time resolution of 6 seconds were generated from measured data. These rainfall series were taken as input to a model that simulated a TBR. Different TBR data series were produced by changing calibration parameters and bucket size of the simulated rain gauge. These data series together with the original rainfall events were used as input to a rainfall-runoff model. Computed runoff and overflow volume from a CSO weir were compared. The differences in rainfall depth, intensity peak and computed runoff due to the depth resolution of the TBR were smaller than expected. A depth resolution of the TBR of 0.2 - 0.3 mm per tip seems to fulfil the requirements in urban hydrology. Errors resulting from depth resolution are small compared to those of calibration (especially false rainfall depth per tip), site exposure, the influence of wind or disregarded areal rainfall distribution.

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.

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