Spatial and Time Warping for Gauge Adjustment of Rainfall Estimates

Many satellite-based estimates use gauge information for bias correction. In general, bias-correction methods are focused on the intensity error and do not explicitly correct possible position or timing errors. However, position and timing errors in rainfall estimates can also lead to errors in the...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Camille Le Coz, Arnold Heemink, Martin Verlaan, Nick van de Giesen
Formato:	article
Lenguaje:	EN
Publicado:	MDPI AG 2021
Materias:	precipitation estimation satellite-based precipitation gauge data IMERG TAHMO warping Meteorology. Climatology QC851-999
Acceso en línea:	https://doaj.org/article/818e95edbb604114943278bebf70b4fe
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:818e95edbb604114943278bebf70b4fe
record_format	dspace
spelling	oai:doaj.org-article:818e95edbb604114943278bebf70b4fe2021-11-25T16:45:42ZSpatial and Time Warping for Gauge Adjustment of Rainfall Estimates10.3390/atmos121115102073-4433https://doaj.org/article/818e95edbb604114943278bebf70b4fe2021-11-01T00:00:00Zhttps://www.mdpi.com/2073-4433/12/11/1510https://doaj.org/toc/2073-4433Many satellite-based estimates use gauge information for bias correction. In general, bias-correction methods are focused on the intensity error and do not explicitly correct possible position or timing errors. However, position and timing errors in rainfall estimates can also lead to errors in the rainfall occurrence or the intensity. This is especially true for localized rainfall events such as the convective rainstorms occurring during the rainy season in sub-Saharan Africa. We investigated the use of warping to correct such errors. The goal was to gauge-adjust satellite-based estimates with respect to the position and the timing of the rain event, instead of its intensity. Warping is a field-deformation method that transforms an image into another one. We compared two methods, spatial warping focusing on the position errors and time warping for the timing errors. They were evaluated on two case studies: a synthetic rainfall event represented by an ellipse and a rain event in southern Ghana during the monsoon season. In both cases, the two warping methods reduced significantly the respective targeted (position or timing) errors. In the southern Ghana case, the average position error was decreased by about 45 km by the spatial warping and the average timing error was decreased from more than 1 h to 0.2 h by the time warping. Both warping methods also improved the continuous statistics on the intensity: the correlation went from 0.18 to at least 0.62 after warping in the southern Ghana case. The spatial warping seems more interesting because of its positive impact on both position and timing errors.Camille Le CozArnold HeeminkMartin VerlaanNick van de GiesenMDPI AGarticleprecipitation estimationsatellite-based precipitationgauge dataIMERGTAHMOwarpingMeteorology. ClimatologyQC851-999ENAtmosphere, Vol 12, Iss 1510, p 1510 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	precipitation estimation satellite-based precipitation gauge data IMERG TAHMO warping Meteorology. Climatology QC851-999
spellingShingle	precipitation estimation satellite-based precipitation gauge data IMERG TAHMO warping Meteorology. Climatology QC851-999 Camille Le Coz Arnold Heemink Martin Verlaan Nick van de Giesen Spatial and Time Warping for Gauge Adjustment of Rainfall Estimates
description	Many satellite-based estimates use gauge information for bias correction. In general, bias-correction methods are focused on the intensity error and do not explicitly correct possible position or timing errors. However, position and timing errors in rainfall estimates can also lead to errors in the rainfall occurrence or the intensity. This is especially true for localized rainfall events such as the convective rainstorms occurring during the rainy season in sub-Saharan Africa. We investigated the use of warping to correct such errors. The goal was to gauge-adjust satellite-based estimates with respect to the position and the timing of the rain event, instead of its intensity. Warping is a field-deformation method that transforms an image into another one. We compared two methods, spatial warping focusing on the position errors and time warping for the timing errors. They were evaluated on two case studies: a synthetic rainfall event represented by an ellipse and a rain event in southern Ghana during the monsoon season. In both cases, the two warping methods reduced significantly the respective targeted (position or timing) errors. In the southern Ghana case, the average position error was decreased by about 45 km by the spatial warping and the average timing error was decreased from more than 1 h to 0.2 h by the time warping. Both warping methods also improved the continuous statistics on the intensity: the correlation went from 0.18 to at least 0.62 after warping in the southern Ghana case. The spatial warping seems more interesting because of its positive impact on both position and timing errors.
format	article
author	Camille Le Coz Arnold Heemink Martin Verlaan Nick van de Giesen
author_facet	Camille Le Coz Arnold Heemink Martin Verlaan Nick van de Giesen
author_sort	Camille Le Coz
title	Spatial and Time Warping for Gauge Adjustment of Rainfall Estimates
title_short	Spatial and Time Warping for Gauge Adjustment of Rainfall Estimates
title_full	Spatial and Time Warping for Gauge Adjustment of Rainfall Estimates
title_fullStr	Spatial and Time Warping for Gauge Adjustment of Rainfall Estimates
title_full_unstemmed	Spatial and Time Warping for Gauge Adjustment of Rainfall Estimates
title_sort	spatial and time warping for gauge adjustment of rainfall estimates
publisher	MDPI AG
publishDate	2021
url	https://doaj.org/article/818e95edbb604114943278bebf70b4fe
work_keys_str_mv	AT camillelecoz spatialandtimewarpingforgaugeadjustmentofrainfallestimates AT arnoldheemink spatialandtimewarpingforgaugeadjustmentofrainfallestimates AT martinverlaan spatialandtimewarpingforgaugeadjustmentofrainfallestimates AT nickvandegiesen spatialandtimewarpingforgaugeadjustmentofrainfallestimates
_version_	1718413028808982528

Spatial and Time Warping for Gauge Adjustment of Rainfall Estimates

Ejemplares similares