{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,3]],"date-time":"2026-04-03T00:22:35Z","timestamp":1775175755102,"version":"3.50.1"},"reference-count":34,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2021,12,13]],"date-time":"2021-12-13T00:00:00Z","timestamp":1639353600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Geoscience Australia","award":["1002B"],"award-info":[{"award-number":["1002B"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The recent development of the smartphone Global Navigation Satellite System (GNSS) chipsets, such as Broadcom BCM47755 and Qualcomm Snapdragon 855 embedded, makes instantaneous and cm level real-time kinematic (RTK) positioning possible with Android-based smartphones. In this contribution we investigate the instantaneous single-baseline RTK performance of Samsung Galaxy S20 and Google Pixel 4 (GP4) smartphones with such chipsets, while making use of dual-frequency L1 + L5 Global Positioning System (GPS), E1 + E5a Galileo, L1 + L5 Quasi-Zenith Satellite System (QZSS) and B1 BeiDou Navigation Satellite System (BDS) code and phase observations in Dunedin, New Zealand. The effects of locating the smartphones in an upright and lying down position were evaluated, and we show that the choice of smartphone configuration can affect the positioning performance even in a zero-baseline setup. In particular, we found non-zero mean and linear trends in the double-differenced carrier-phase residuals for one of the smartphone models when lying down, which become absent when in an upright position. This implies that the two assessed smartphones have different antenna gain pattern and antenna sensitivity to interferences. Finally, we demonstrate, for the first time, a near hundred percent (98.7% to 99.9%) instantaneous RTK integer least-squares success rate for one of the smartphone models and cm level positioning precision while using short-baseline experiments with internal and external antennas, respectively.<\/jats:p>","DOI":"10.3390\/s21248318","type":"journal-article","created":{"date-parts":[[2021,12,13]],"date-time":"2021-12-13T03:14:29Z","timestamp":1639365269000},"page":"8318","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":38,"title":["Instantaneous, Dual-Frequency, Multi-GNSS Precise RTK Positioning Using Google Pixel 4 and Samsung Galaxy S20 Smartphones for Zero and Short Baselines"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7918-2078","authenticated-orcid":false,"given":"Chien Zheng","family":"Yong","sequence":"first","affiliation":[{"name":"National School of Surveying, University of Otago, 310 Castle Street, Dunedin 9016, New Zealand"},{"name":"Faculty of Built Environment and Surveying, Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5073-4457","authenticated-orcid":false,"given":"Robert","family":"Odolinski","sequence":"additional","affiliation":[{"name":"National School of Surveying, University of Otago, 310 Castle Street, Dunedin 9016, New Zealand"}]},{"given":"Safoora","family":"Zaminpardaz","sequence":"additional","affiliation":[{"name":"School of Science, College of Science, Engineering and Health, RMIT University, GPO Box 2476V, Melbourne, VIC 3001, Australia"}]},{"given":"Michael","family":"Moore","sequence":"additional","affiliation":[{"name":"Geoscience Australia, GPO Box 378, Canberra, ACT 2601, Australia"}]},{"given":"Eldar","family":"Rubinov","sequence":"additional","affiliation":[{"name":"FrontierSI, Goods Shed, Village Street, Docklands, VIC 3008, Australia"}]},{"given":"Jeremiah","family":"Er","sequence":"additional","affiliation":[{"name":"National School of Surveying, University of Otago, 310 Castle Street, Dunedin 9016, New Zealand"}]},{"given":"Mike","family":"Denham","sequence":"additional","affiliation":[{"name":"National School of Surveying, University of Otago, 310 Castle Street, Dunedin 9016, New Zealand"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Mongredien, C., Doyen, J.P., Strom, M., and Ammann, D. 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