Rainfall estimation using moving cars as rain gauges – laboratory experiments
The spatial assessment of short time-step precipitation is a challenging task. Low density of observation networks, as well as the bias in radar rainfall estimation motivated the new idea of exploiting cars as moving rain gauges with windshield wipers or optical sensors as measurement devices. In a...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-11-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | http://www.hydrol-earth-syst-sci.net/17/4701/2013/hess-17-4701-2013.pdf |
| _version_ | 1818023477684207616 |
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| author | E. Rabiei U. Haberlandt M. Sester D. Fitzner |
| author_facet | E. Rabiei U. Haberlandt M. Sester D. Fitzner |
| author_sort | E. Rabiei |
| collection | DOAJ |
| description | The spatial assessment of short time-step precipitation is a challenging
task. Low density of observation networks, as well as the bias in radar
rainfall estimation motivated the new idea of exploiting cars as moving rain
gauges with windshield wipers or optical sensors as measurement devices. In
a preliminary study, this idea has been tested with computer experiments
(Haberlandt and Sester, 2010). The results have shown that
a high number of possibly inaccurate measurement devices (moving cars)
provide more reliable areal rainfall estimations than a lower number of
precise measurement devices (stationary gauges). Instead of assuming a
relationship between wiper frequency (<i>W</i>) and rainfall intensity (<i>R</i>) with an
arbitrary error, the main objective of this study is to derive valid <i>W</i>–<i>R</i>
relationships between sensor readings and rainfall intensity by laboratory
experiments. Sensor readings involve the wiper speed, as well as optical
sensors which can be placed on cars and are usually made for automating
wiper activities. A rain simulator with the capability of producing a wide
range of rainfall intensities is designed and constructed. The wiper speed
and two optical sensors are used in the laboratory to measure rainfall
intensities, and compare it with tipping bucket readings as reference.
Furthermore, the effect of the car speed on the estimation of rainfall using
a car speed simulator device is investigated. The results show that the
sensor readings, which are observed from manual wiper speed adjustment
according to the front visibility, can be considered as a strong indicator
for rainfall intensity, while the automatic wiper adjustment show weaker
performance. Also the sensor readings from optical sensors showed promising
results toward measuring rainfall rate. It is observed that the car speed
has a significant effect on the rainfall measurement. This effect is highly
dependent on the rain type as well as the windshield angle. |
| first_indexed | 2024-12-10T03:44:57Z |
| format | Article |
| id | doaj.art-d59801cb8d34454fb6f5c810a41d4678 |
| institution | Directory Open Access Journal |
| issn | 1027-5606 1607-7938 |
| language | English |
| last_indexed | 2024-12-10T03:44:57Z |
| publishDate | 2013-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Hydrology and Earth System Sciences |
| spelling | doaj.art-d59801cb8d34454fb6f5c810a41d46782022-12-22T02:03:27ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382013-11-0117114701471210.5194/hess-17-4701-2013Rainfall estimation using moving cars as rain gauges – laboratory experimentsE. Rabiei0U. Haberlandt1M. Sester2D. Fitzner3Institute of Water Resources Management, Hydrology and Agricultural Hydraulic Engineering, Leibniz Universität Hannover, Hanover, GermanyInstitute of Water Resources Management, Hydrology and Agricultural Hydraulic Engineering, Leibniz Universität Hannover, Hanover, GermanyInstitute of Cartography and Geoinformatics, Leibniz Universität Hannover, Hanover, GermanyInstitute of Cartography and Geoinformatics, Leibniz Universität Hannover, Hanover, GermanyThe spatial assessment of short time-step precipitation is a challenging task. Low density of observation networks, as well as the bias in radar rainfall estimation motivated the new idea of exploiting cars as moving rain gauges with windshield wipers or optical sensors as measurement devices. In a preliminary study, this idea has been tested with computer experiments (Haberlandt and Sester, 2010). The results have shown that a high number of possibly inaccurate measurement devices (moving cars) provide more reliable areal rainfall estimations than a lower number of precise measurement devices (stationary gauges). Instead of assuming a relationship between wiper frequency (<i>W</i>) and rainfall intensity (<i>R</i>) with an arbitrary error, the main objective of this study is to derive valid <i>W</i>–<i>R</i> relationships between sensor readings and rainfall intensity by laboratory experiments. Sensor readings involve the wiper speed, as well as optical sensors which can be placed on cars and are usually made for automating wiper activities. A rain simulator with the capability of producing a wide range of rainfall intensities is designed and constructed. The wiper speed and two optical sensors are used in the laboratory to measure rainfall intensities, and compare it with tipping bucket readings as reference. Furthermore, the effect of the car speed on the estimation of rainfall using a car speed simulator device is investigated. The results show that the sensor readings, which are observed from manual wiper speed adjustment according to the front visibility, can be considered as a strong indicator for rainfall intensity, while the automatic wiper adjustment show weaker performance. Also the sensor readings from optical sensors showed promising results toward measuring rainfall rate. It is observed that the car speed has a significant effect on the rainfall measurement. This effect is highly dependent on the rain type as well as the windshield angle.http://www.hydrol-earth-syst-sci.net/17/4701/2013/hess-17-4701-2013.pdf |
| spellingShingle | E. Rabiei U. Haberlandt M. Sester D. Fitzner Rainfall estimation using moving cars as rain gauges – laboratory experiments Hydrology and Earth System Sciences |
| title | Rainfall estimation using moving cars as rain gauges – laboratory experiments |
| title_full | Rainfall estimation using moving cars as rain gauges – laboratory experiments |
| title_fullStr | Rainfall estimation using moving cars as rain gauges – laboratory experiments |
| title_full_unstemmed | Rainfall estimation using moving cars as rain gauges – laboratory experiments |
| title_short | Rainfall estimation using moving cars as rain gauges – laboratory experiments |
| title_sort | rainfall estimation using moving cars as rain gauges ndash laboratory experiments |
| url | http://www.hydrol-earth-syst-sci.net/17/4701/2013/hess-17-4701-2013.pdf |
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