Estimation of raindrop size distribution and rain rate with infrared surveillance camera in dark conditions
<p>This study estimated raindrop size distribution (DSD) and rainfall intensity with an infrared surveillance camera in dark conditions. Accordingly, rain streaks were extracted using a <span class="inline-formula"><i>k</i></span>-nearest-neighbor (KNN)-based...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-02-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/16/707/2023/amt-16-707-2023.pdf |
| _version_ | 1828039274234118144 |
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| author | J. Lee J. Byun J. Baik C. Jun H.-J. Kim |
| author_facet | J. Lee J. Byun J. Baik C. Jun H.-J. Kim |
| author_sort | J. Lee |
| collection | DOAJ |
| description | <p>This study estimated raindrop size distribution (DSD) and
rainfall intensity with an infrared surveillance camera in dark conditions. Accordingly, rain streaks were extracted using a <span class="inline-formula"><i>k</i></span>-nearest-neighbor (KNN)-based algorithm. The rainfall intensity was estimated using DSD based on a physical optics analysis. The estimated DSD was verified using a disdrometer for the two rainfall events. The results are summarized as follows. First, a KNN-based algorithm can accurately recognize rain streaks from complex backgrounds captured by the camera. Second, the number concentration of raindrops obtained through closed-circuit television (CCTV) images had values between 100 and 1000 mm<span class="inline-formula"><sup>−1</sup></span> m<span class="inline-formula"><sup>−3</sup></span>, and the root mean square error (RMSE) for the number concentration by CCTV and PARticle SIze and VELocity (PARSIVEL) was 72.3 and 131.6 mm<span class="inline-formula"><sup>−1</sup></span> m<span class="inline-formula"><sup>−3</sup></span> in the 0.5 to 1.5 mm section. Third, the maximum raindrop diameter and the number concentration of 1 mm or less produced similar results during the period with a high ratio of diameters of 3 mm or less. Finally, after comparing with the 15 min cumulative PARSIVEL rain rate, the mean absolute percent error (MAPE) was 49 % and 23 %, respectively. In addition, the differences according to rain rate are that the MAPE was 36 % at a rain rate of less than 2 mm h<span class="inline-formula"><sup>−1</sup></span> and 80 % at a rate above 2 mm h<span class="inline-formula"><sup>−1</sup></span>. Also, when the rain rate was greater than 5 mm h<span class="inline-formula"><sup>−1</sup></span>, MAPE was 33 %. We confirmed the possibility of estimating an image-based DSD and rain rate obtained based on low-cost equipment during dark conditions.</p> |
| first_indexed | 2024-04-10T16:39:22Z |
| format | Article |
| id | doaj.art-cacd15842ba5440294dc954d0bbce3b1 |
| institution | Directory Open Access Journal |
| issn | 1867-1381 1867-8548 |
| language | English |
| last_indexed | 2024-04-10T16:39:22Z |
| publishDate | 2023-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj.art-cacd15842ba5440294dc954d0bbce3b12023-02-08T10:11:44ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482023-02-011670772510.5194/amt-16-707-2023Estimation of raindrop size distribution and rain rate with infrared surveillance camera in dark conditionsJ. LeeJ. ByunJ. BaikC. JunH.-J. Kim<p>This study estimated raindrop size distribution (DSD) and rainfall intensity with an infrared surveillance camera in dark conditions. Accordingly, rain streaks were extracted using a <span class="inline-formula"><i>k</i></span>-nearest-neighbor (KNN)-based algorithm. The rainfall intensity was estimated using DSD based on a physical optics analysis. The estimated DSD was verified using a disdrometer for the two rainfall events. The results are summarized as follows. First, a KNN-based algorithm can accurately recognize rain streaks from complex backgrounds captured by the camera. Second, the number concentration of raindrops obtained through closed-circuit television (CCTV) images had values between 100 and 1000 mm<span class="inline-formula"><sup>−1</sup></span> m<span class="inline-formula"><sup>−3</sup></span>, and the root mean square error (RMSE) for the number concentration by CCTV and PARticle SIze and VELocity (PARSIVEL) was 72.3 and 131.6 mm<span class="inline-formula"><sup>−1</sup></span> m<span class="inline-formula"><sup>−3</sup></span> in the 0.5 to 1.5 mm section. Third, the maximum raindrop diameter and the number concentration of 1 mm or less produced similar results during the period with a high ratio of diameters of 3 mm or less. Finally, after comparing with the 15 min cumulative PARSIVEL rain rate, the mean absolute percent error (MAPE) was 49 % and 23 %, respectively. In addition, the differences according to rain rate are that the MAPE was 36 % at a rain rate of less than 2 mm h<span class="inline-formula"><sup>−1</sup></span> and 80 % at a rate above 2 mm h<span class="inline-formula"><sup>−1</sup></span>. Also, when the rain rate was greater than 5 mm h<span class="inline-formula"><sup>−1</sup></span>, MAPE was 33 %. We confirmed the possibility of estimating an image-based DSD and rain rate obtained based on low-cost equipment during dark conditions.</p>https://amt.copernicus.org/articles/16/707/2023/amt-16-707-2023.pdf |
| spellingShingle | J. Lee J. Byun J. Baik C. Jun H.-J. Kim Estimation of raindrop size distribution and rain rate with infrared surveillance camera in dark conditions Atmospheric Measurement Techniques |
| title | Estimation of raindrop size distribution and rain rate with infrared surveillance camera in dark conditions |
| title_full | Estimation of raindrop size distribution and rain rate with infrared surveillance camera in dark conditions |
| title_fullStr | Estimation of raindrop size distribution and rain rate with infrared surveillance camera in dark conditions |
| title_full_unstemmed | Estimation of raindrop size distribution and rain rate with infrared surveillance camera in dark conditions |
| title_short | Estimation of raindrop size distribution and rain rate with infrared surveillance camera in dark conditions |
| title_sort | estimation of raindrop size distribution and rain rate with infrared surveillance camera in dark conditions |
| url | https://amt.copernicus.org/articles/16/707/2023/amt-16-707-2023.pdf |
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