{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T16:24:21Z","timestamp":1781281461133,"version":"3.54.1"},"reference-count":39,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2020,1,26]],"date-time":"2020-01-26T00:00:00Z","timestamp":1579996800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Strategic Priority Research Program of the Chinese Academy of Sciences","award":["XDA20100306"],"award-info":[{"award-number":["XDA20100306"]}]},{"DOI":"10.13039\/501100001809","name":"the National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["U170310011"],"award-info":[{"award-number":["U170310011"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"the Basic Research Operating Expenses of the Central Level Nonprofit Research Institutes","award":["IDM2016002"],"award-info":[{"award-number":["IDM2016002"]}]},{"name":"Xinjiang Uygur Autonomous Region high-level personnel funding","award":["2017-41"],"award-info":[{"award-number":["2017-41"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Low accuracy and coarse spatial resolution are the two main drawbacks of satellite precipitation products. Therefore, calibration and downscaling are necessary before these products are applied. This study proposes a two-step framework to improve the accuracy of satellite precipitation estimates. The first step is data merging based on optimum interpolation (OI), and the second step is downscaling based on geographically weighted regression (GWR); therefore, the framework is called OI-GWR. An Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (GPM) (IMERG) product is used to demonstrate the effectiveness of OI-GWR in the Tianshan Mountains, China. First, the original IMERG precipitation data (OIMERG) are merged with rain gauge data using the OI method to produce corrected IMERG precipitation data (CIMERG). Then, using CIMERG as the first guess and the normalized difference vegetation index (NDVI) as the auxiliary variable, GWR is utilized for spatial downscaling. The two-step OI-GWR method is compared with several traditional methods, including GWR downscaling (Ori_GWR) and spline interpolation. The cross-validation results show that (1) the OI method noticeably improves the accuracy of OIMERG, and (2) the 1-km downscaled data obtained using OI-GWR are much better than those obtained from Ori_GWR, spline interpolation, and OIMERG. The proposed OI-GWR method can contribute to the development of high-resolution and high-accuracy regional precipitation datasets. However, it should be noted that the method proposed in this study cannot be applied in regions without any meteorological stations. In addition, further efforts will be needed to achieve daily- or hourly-scale downscaling of precipitation.<\/jats:p>","DOI":"10.3390\/rs12030398","type":"journal-article","created":{"date-parts":[[2020,1,27]],"date-time":"2020-01-27T07:41:11Z","timestamp":1580110871000},"page":"398","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":35,"title":["The Development of a Two-Step Merging and Downscaling Method for Satellite Precipitation Products"],"prefix":"10.3390","volume":"12","author":[{"given":"Xinyu","family":"Lu","sequence":"first","affiliation":[{"name":"Institute of Desert Meteorology, China Meteorological Administration. Urumqi 830002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guoqiang","family":"Tang","sequence":"additional","affiliation":[{"name":"Coldwater Lab, University of Saskatchewan, Canmore T1W 3G1, Canada"},{"name":"Center for Hydrology, University of Saskatchewan, Saskatchewan S7N 1K2, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiuqin","family":"Wang","sequence":"additional","affiliation":[{"name":"Institute of Desert Meteorology, China Meteorological Administration. Urumqi 830002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yan","family":"Liu","sequence":"additional","affiliation":[{"name":"Institute of Desert Meteorology, China Meteorological Administration. Urumqi 830002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ming","family":"Wei","sequence":"additional","affiliation":[{"name":"Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, \r\nNanjing University of Information Science & Technology, Nanjing 210044, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yingxin","family":"Zhang","sequence":"additional","affiliation":[{"name":"Institute of Desert Meteorology, China Meteorological Administration. Urumqi 830002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,1,26]]},"reference":[{"key":"ref_1","unstructured":"Sorooshian, S. (GEWEX Newsl., 2004). 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