{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T01:39:36Z","timestamp":1760233176901,"version":"build-2065373602"},"reference-count":30,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2022,12,24]],"date-time":"2022-12-24T00:00:00Z","timestamp":1671840000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Key R&amp;D Program of China","award":["2021YFA0716500","61973328","91938301","2020N259","GXWD20201231165807008","20200830225317001","ZDSYS20210623091807023"],"award-info":[{"award-number":["2021YFA0716500","61973328","91938301","2020N259","GXWD20201231165807008","20200830225317001","ZDSYS20210623091807023"]}]},{"name":"National Natural Science Foundation of China","award":["2021YFA0716500","61973328","91938301","2020N259","GXWD20201231165807008","20200830225317001","ZDSYS20210623091807023"],"award-info":[{"award-number":["2021YFA0716500","61973328","91938301","2020N259","GXWD20201231165807008","20200830225317001","ZDSYS20210623091807023"]}]},{"name":"Key Basic Research Projects of Shenzhen Science and Technology Commission","award":["2021YFA0716500","61973328","91938301","2020N259","GXWD20201231165807008","20200830225317001","ZDSYS20210623091807023"],"award-info":[{"award-number":["2021YFA0716500","61973328","91938301","2020N259","GXWD20201231165807008","20200830225317001","ZDSYS20210623091807023"]}]},{"name":"Shenzhen Science and Technology Program","award":["2021YFA0716500","61973328","91938301","2020N259","GXWD20201231165807008","20200830225317001","ZDSYS20210623091807023"],"award-info":[{"award-number":["2021YFA0716500","61973328","91938301","2020N259","GXWD20201231165807008","20200830225317001","ZDSYS20210623091807023"]}]},{"name":"Shenzhen Key Laboratory of Navigation and Communication Integration","award":["2021YFA0716500","61973328","91938301","2020N259","GXWD20201231165807008","20200830225317001","ZDSYS20210623091807023"],"award-info":[{"award-number":["2021YFA0716500","61973328","91938301","2020N259","GXWD20201231165807008","20200830225317001","ZDSYS20210623091807023"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Numerous organizations and Analysis Centers (AC) currently offer various Ambiguity Resolution (AR) products using various methodologies. However, there are no associated studies on their use for time-frequency transfer. This paper examines 16 Multi-GNSS Experiment (MGEX) stations with external high-precision atomic clocks to constitute 15 international time comparison links, and uses AR products data from CNES, SGG, CODE, and PRIDE laboratories, using three ambiguity-fixed strategies, to thoroughly evaluate the effects of various strategies and AR products for high-precision time-frequency transfer. We reach the following results by using the IGS final clock product as a reference and comparing it to ambiguity-float. With various ambiguity-fixed procedures, the time stability Standard Deviation (STD) of time transfer is increased for a single GPS, and the improvement ranges from 10 to 40%. The frequency stability has barely improved; up to 40%, the most notable improvement comes from FCB with GRM products. The time stability STD of combinations has improved after the addition of the Galileo system compared to the single GPS, and the improvement ranges from 2 to 9%. Most strategies have been improved, while a few techniques have been weakened with the GEC (GPS + Galileo + BDS) combination. We feel that the stability has not significantly increased with the systems\u2019 increase in terms of short-term stability after comparing multiple groups of linkages.<\/jats:p>","DOI":"10.3390\/rs15010092","type":"journal-article","created":{"date-parts":[[2022,12,27]],"date-time":"2022-12-27T07:31:56Z","timestamp":1672126316000},"page":"92","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Using Various Analysis Center Products to Assess the Time-Frequency Transfer Performance of GPS\/Galileo\/BDS PPPAR Methods"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4289-3252","authenticated-orcid":false,"given":"Mingjun","family":"Ouyang","sequence":"first","affiliation":[{"name":"School of Electronics and Communication Engineering, Sun Yat-Sen University, Guangzhou 510006, China"},{"name":"Shenzhen Key Laboratory of Navigation and Communication Integration, Shenzhen 518125, China"}]},{"given":"Xiangwei","family":"Zhu","sequence":"additional","affiliation":[{"name":"School of Electronics and Communication Engineering, Sun Yat-Sen University, Guangzhou 510006, China"},{"name":"Shenzhen Key Laboratory of Navigation and Communication Integration, Shenzhen 518125, China"},{"name":"School of System Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, China"}]},{"given":"Ruite","family":"Yi","sequence":"additional","affiliation":[{"name":"Shenzhen Key Laboratory of Navigation and Communication Integration, Shenzhen 518125, China"},{"name":"School of System Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, China"}]},{"given":"Daqian","family":"Lyu","sequence":"additional","affiliation":[{"name":"College of Electronic Engineering, National University of Defense Technology, Hefei 230037, China"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,24]]},"reference":[{"key":"ref_1","first-page":"1997","article-title":"Comparison of two-way and beidou common view time transfer between ntsc and beij station","volume":"1049\u20131050","author":"Zhang","year":"2014","journal-title":"Adv. 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