{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,8]],"date-time":"2025-11-08T17:55:32Z","timestamp":1762624532518,"version":"build-2065373602"},"reference-count":31,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,12,22]],"date-time":"2020-12-22T00:00:00Z","timestamp":1608595200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Shanghai Key Laboratory of Space Navigation and Positioning Techniques","award":["201901"],"award-info":[{"award-number":["201901"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["42030109"],"award-info":[{"award-number":["42030109"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>China\u2019s BeiDou navigation satellite system (BDS) has finished global constellation construction and can achieve joint solution, simultaneously relying on the B1I + B3I signals of the BDS-2 and BDS-3 satellites. For reasons mostly related to chip shape distortions, navigation satellite observations are corrupted by receiver-dependent code biases. Those biases are brought into observation residuals and degrade the pseudorange correction accuracy. Herein, we present a code bias estimation algorithm, using what we found to be an obvious clustering code bias phenomenon between the BDS-2 and BDS-3 satellites, leading to the systematic biases existing in the BDS-2+3 joint solution. Therefore, we propose a BDS-2+3 joint solution with code bias self-calibration, which can accurately strip off clustering code biases between the BDS-2 and BDS-3 satellites, and can greatly improve precise point positioning (PPP) convergence speed and accuracy. The statistics showed that the residual biases and root mean square (RMS) improved by 36% and 15% and the convergence time improved by approximately 35%. In the convergence stage, the positioning accuracy improved by approximately 38% and 21% in the horizontal and vertical directions, respectively. Meanwhile, in the post-convergence stage, the accuracy improved by approximately 10%.<\/jats:p>","DOI":"10.3390\/rs13010015","type":"journal-article","created":{"date-parts":[[2020,12,22]],"date-time":"2020-12-22T20:39:29Z","timestamp":1608669569000},"page":"15","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Clustering Code Biases between BDS-2 and BDS-3 Satellites and Effects on Joint Solution"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6694-4360","authenticated-orcid":false,"given":"Liang","family":"Chen","sequence":"first","affiliation":[{"name":"School of Electronic and Information Engineering, Beihang University, 37 Xueyuan Road, Beijing 100191, China"},{"name":"Shanghai Key Laboratory of Space Navigation and Positioning Techniques, Shanghai 200030, China"}]},{"given":"Min","family":"Li","sequence":"additional","affiliation":[{"name":"GNSS Research Center, Wuhan University, 129 Luoyu Road, Wuhan 430079, China"}]},{"given":"Ying","family":"Zhao","sequence":"additional","affiliation":[{"name":"National Quality Inspection and Testing Center for Surveying and Mapping Products, 28 Lianhuachi West Road, Beijing 100830, China"}]},{"given":"Fu","family":"Zheng","sequence":"additional","affiliation":[{"name":"School of Electronic and Information Engineering, Beihang University, 37 Xueyuan Road, Beijing 100191, China"},{"name":"Research Institute for Frontier Science, Beihang University, 37 Xueyuan Road, Beijing 100191, China"}]},{"given":"Xuejun","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Electronic and Information Engineering, Beihang University, 37 Xueyuan Road, Beijing 100191, China"}]},{"given":"Chuang","family":"Shi","sequence":"additional","affiliation":[{"name":"School of Electronic and Information Engineering, Beihang University, 37 Xueyuan Road, Beijing 100191, China"},{"name":"Research Institute for Frontier Science, Beihang University, 37 Xueyuan Road, Beijing 100191, China"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"931","DOI":"10.1109\/7.104264","article-title":"Variability of GPS Satellite Differential Group Delay Biases","volume":"27","author":"Coco","year":"1991","journal-title":"IEEE Trans. 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