{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,23]],"date-time":"2025-12-23T05:29:19Z","timestamp":1766467759599,"version":"build-2065373602"},"reference-count":70,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2022,12,17]],"date-time":"2022-12-17T00:00:00Z","timestamp":1671235200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Inter-satellite links (ISLs) can improve the performance of the Global Navigation Satellite System (GNSS) in terms of precise orbit determination, communication, and data-exchange capabilities. This research aimed to evaluate a simulation-based processing strategy involving the exploitation of ISLs in orbit determination of Galileo satellites, which are not equipped with operational ISLs. The performance of the estimation process is first tested based on relative weighting coefficients obtained with methods of variance component estimation (VCE) varying in the complexity of the calculations. Inclusion of biases in the ISL measurements allows evaluation of the processing strategy and assessment of the impact of three different sets of ground stations: 44 and 16 stations distributed globally and 16 located in Europe. The results indicate that using different VCE approaches might lower orbit errors by up to 20% with a negligible impact on clock estimation. Depending on the applied ISL connectivity scheme, ISL range bias can be estimated with RMS between 10% to 30% of initial bias values. The accuracy of bias estimation may be associated with weighting approach and the number of ground stations. The results of this study show how introducing VCE with various simulation parameters into the processing chain might increase the accuracy of the orbit estimation.<\/jats:p>","DOI":"10.3390\/rs14246387","type":"journal-article","created":{"date-parts":[[2022,12,19]],"date-time":"2022-12-19T08:41:41Z","timestamp":1671439301000},"page":"6387","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Simulation of the Use of Variance Component Estimation in Relative Weighting of Inter-Satellite Links and GNSS Measurements"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6738-741X","authenticated-orcid":false,"given":"Tomasz","family":"Kur","sequence":"first","affiliation":[{"name":"Centrum Bada\u0144 Kosmicznych Polskiej Akademii Nauk (CBK PAN) Bartycka 18A, 00-716 Warszawa, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3989-4625","authenticated-orcid":false,"given":"Tomasz","family":"Liwosz","sequence":"additional","affiliation":[{"name":"Faculty of Geodesy and Cartography, Warsaw University of Technology, Pl. 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Space Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1007\/s10291-020-00985-0","article-title":"Initial Results of Distributed Autonomous Orbit Determination for Beidou BDS-3 Satellites Based on Inter-Satellite Link Measurements","volume":"24","author":"Guo","year":"2020","journal-title":"GPS Solut."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1155","DOI":"10.1007\/s00190-018-1113-7","article-title":"Initial Results of Centralized Autonomous Orbit Determination of the New-Generation BDS Satellites with Inter-Satellite Link Measurements","volume":"92","author":"Tang","year":"2018","journal-title":"J. Geod."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1007\/s10291-021-01177-0","article-title":"Full-ISL Clock Offset Estimation and Prediction Algorithm for BDS3","volume":"25","author":"Pan","year":"2021","journal-title":"GPS Solut."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"999","DOI":"10.1007\/s10291-016-0587-0","article-title":"Timeslot Scheduling of Inter-Satellite Links Based on a System of a Narrow Beam with Time Division","volume":"21","author":"Yang","year":"2017","journal-title":"GPS Solut."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2421","DOI":"10.1016\/j.asr.2021.12.039","article-title":"Inter-Satellite Time Synchronization and Ranging Link Assignment for Autonomous Navigation Satellite Constellations","volume":"69","author":"Sun","year":"2022","journal-title":"Adv. Space Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3156","DOI":"10.1016\/j.asr.2022.07.030","article-title":"Emerging Errors in the Orientation of the Constellation in GNSS Autonomous Orbit Determination Based on Inter-Satellite Link Measurements","volume":"70","author":"Zhou","year":"2022","journal-title":"Adv. Space Res."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1016\/j.asr.2019.03.017","article-title":"Parameter Decomposition Filter of BDS-3 Combined Orbit Determination Using Inter-Satellite Link Observations","volume":"64","author":"Gong","year":"2019","journal-title":"Adv. Space Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1016\/j.asr.2010.07.019","article-title":"Inter-Satellite Links for Satellite Autonomous Integrity Monitoring","volume":"47","author":"Tavella","year":"2011","journal-title":"Adv. Space Res."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"4734","DOI":"10.1016\/j.asr.2021.05.011","article-title":"Simulation of Inter-Satellite Link Schemes for Use in Precise Orbit Determination and Clock Estimation","volume":"68","author":"Kur","year":"2021","journal-title":"Adv. Space Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1007\/978-981-15-3711-0_6","article-title":"The Influence of Station Distribution on the BeiDou-3 Inter-Satellite Link Enhanced Orbit Determination","volume":"Volume 651","author":"Sun","year":"2020","journal-title":"China Satellite Navigation Conference (CSNC) 2020 Proceedings: Volume II. CSNC 2020"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2177","DOI":"10.1016\/j.asr.2015.07.045","article-title":"Impact of Tracking Station Distribution Structure on BeiDou Satellite Orbit Determination","volume":"56","author":"Zhang","year":"2015","journal-title":"Adv. Space Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4011","DOI":"10.1016\/j.asr.2021.02.027","article-title":"Orbit Determination of BDS-3 Satellite Based on Regional Ground Tracking Station and Inter-Satellite Link Observations","volume":"67","author":"Zhang","year":"2021","journal-title":"Adv. Space Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"4069","DOI":"10.1016\/j.asr.2021.07.022","article-title":"Optimization of Ground Tracking Stations for BDS-3 Satellite Orbit Determination","volume":"68","author":"Zhang","year":"2021","journal-title":"Adv. Space Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1186\/s43020-022-00083-1","article-title":"Precise Orbit Determination for a Large LEO Constellation with Inter-Satellite Links and the Measurements from Different Ground Networks: A Simulation Study","volume":"3","author":"He","year":"2022","journal-title":"Satell. Navig."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1016\/j.actaastro.2019.07.029","article-title":"Contribution Analysis of Inter-Satellite Ranging Observation to BDS-2 Satellite Orbit Determination Based on Regional Tracking Stations","volume":"164","author":"Zhang","year":"2019","journal-title":"Acta Astronaut."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1007\/s10291-020-01067-x","article-title":"BeiDou-3 Broadcast Clock Estimation by Integration of Observations of Regional Tracking Stations and Inter-Satellite Links","volume":"25","author":"Yang","year":"2021","journal-title":"GPS Solut."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1007\/s10291-022-01330-3","article-title":"Precise Orbit Determination for BDS-3 GEO Satellites Enhanced by Intersatellite Links","volume":"27","author":"Li","year":"2023","journal-title":"GPS Solut."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Xie, X., Geng, T., Zhao, Q., Liu, J., and Wang, B. (2017). Performance of BDS-3: Measurement Quality Analysis, Precise Orbit and Clock Determination. Sensors, 17.","DOI":"10.3390\/s17061233"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1007\/s10291-019-0823-5","article-title":"Precise Orbit Determination for BDS-3 Satellites Using Satellite-Ground and Inter-Satellite Link Observations","volume":"23","author":"Xie","year":"2019","journal-title":"GPS Solut."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1007\/s10291-020-00995-y","article-title":"Assessment of BDS-3 Global Positioning Service: Ephemeris, SPP, PPP, RTK, and New Signal","volume":"24","author":"Shi","year":"2020","journal-title":"GPS Solut."},{"key":"ref_24","unstructured":"Zhu, Y., Zhang, Q., Mao, Y., Cui, X., Cai, C., and Zhang, R. Comprehensive Performance Review of BDS-3 after One-Year Official Operation, Adv. Space Res., in press."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1007\/s10291-018-0816-9","article-title":"Comparing Satellite Orbit Determination by Batch Processing and Extended Kalman Filtering Using Inter-Satellite Link Measurements of the next-Generation BeiDou Satellites","volume":"23","author":"Ren","year":"2019","journal-title":"GPS Solut."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1007\/s10291-018-0784-0","article-title":"In-Orbit Performance Assessment of BeiDou Intersatellite Link Ranging","volume":"22","author":"Zhou","year":"2018","journal-title":"GPS Solut."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.asr.2017.10.004","article-title":"Time Synchronization of New-Generation BDS Satellites Using Inter-Satellite Link Measurements","volume":"61","author":"Pan","year":"2018","journal-title":"Adv. Space Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1007\/s00190-020-01394-4","article-title":"Orbit and Clock Analysis of BDS-3 Satellites Using Inter-Satellite Link Observations","volume":"94","author":"Xie","year":"2020","journal-title":"J. Geod."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1390","DOI":"10.1016\/j.asr.2016.06.007","article-title":"Improvement of Orbit Determination Accuracy for Beidou Navigation Satellite System with Two-Way Satellite Time Frequency Transfer","volume":"58","author":"Tang","year":"2016","journal-title":"Adv. Space Res."},{"key":"ref_30","unstructured":"(2022, November 22). An Official Website of the European Union. Available online: https:\/\/defence-industry-space.ec.europa.eu\/commission-awards-eu147-bn-contracts-launch-2nd-generation-galileo-satellites-2021-01-20_en."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"4753","DOI":"10.1016\/j.asr.2021.03.008","article-title":"Precise Orbit and Earth Parameter Determination Supported by LEO Satellites, Inter-Satellite Links and Synchronized Clocks of a Future GNSS","volume":"68","author":"Michalak","year":"2021","journal-title":"Adv. Space Res."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1007\/s00190-021-01534-4","article-title":"Galileo Precise Orbit Determination with Optical Two-Way Links (OTWL): A Continuous Wave Laser Ranging and Time Transfer Concept","volume":"95","author":"Marz","year":"2021","journal-title":"J. Geod."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1558","DOI":"10.1016\/j.asr.2020.06.028","article-title":"Galileo POD Using Optical Inter-Satellite Links: A Simulation Study","volume":"66","author":"Schlicht","year":"2020","journal-title":"Adv. Space Res."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s40328-020-00322-4","article-title":"The Application of Inter-Satellite Links Connectivity Schemes in Various Satellite Navigation Systems for Orbit and Clock Corrections Determination: Simulation Study","volume":"56","author":"Kur","year":"2021","journal-title":"Acta Geod. Geophys."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Glaser, S., Michalak, G., Konig, R., Mannel, B., and Schuh, H. (2020, January 23\u201324). Future GNSS Infrastructure for Improved Geodetic Reference Frames. Proceedings of the 2020 European Navigation Conference (ENC), Dresden, Germany.","DOI":"10.23919\/ENC48637.2020.9317460"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1395","DOI":"10.1007\/s10291-017-0626-5","article-title":"Globalization Highlight: Orbit Determination Using BeiDou Inter-Satellite Ranging Measurements","volume":"21","author":"Yang","year":"2017","journal-title":"GPS Solut."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"687","DOI":"10.1007\/s11434-010-0074-x","article-title":"Precise Orbit Determination for Geostationary Satellites with Multiple Tracking Techniques","volume":"55","author":"Guo","year":"2010","journal-title":"Chin. Sci. Bull."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1016\/j.chinastron.2009.09.009","article-title":"The Model of Radio Two-Way Time Comparison between Satellite and Station and Experimental Analysis","volume":"33","author":"Liu","year":"2009","journal-title":"Chin. Astron. Astrophys."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Shi, L.Y., Xiang, W., and Tang, X.M. (2011, January 29\u201330). A Link Assignment Algorithm for GNSS with Crosslink Ranging. Proceedings of the 2011 International Conference on Localization and GNSS, ICL-GNSS 2011, Tampere, Finland.","DOI":"10.1109\/ICL-GNSS.2011.5955268"},{"key":"ref_40","unstructured":"Xu, B., Han, K., Ren, Q., Gong, W., Shao, F., Wang, Y., and Chang, J. An Optimized Strategy for Inter-Satellite Links Assignments in GNSS, Adv. Space Res., in press."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2084","DOI":"10.1016\/j.asr.2012.12.020","article-title":"Establishment Criteria, Routing Algorithms and Probability of Use of Inter-Satellite Links in Mixed Navigation Constellations","volume":"51","author":"Han","year":"2013","journal-title":"Adv. Space Res."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1109\/49.553679","article-title":"ATM-Based Routing in LEO\/MEO Satellite Networks with Intersatellite Links","volume":"15","author":"Werner","year":"1997","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1002\/sat.1032","article-title":"Satellite Constellation of MEO and IGSO Network Routing with Dynamic Grouping","volume":"31","author":"Yi","year":"2013","journal-title":"Int. J. Satell. Commun. Netw."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"2574","DOI":"10.1016\/j.asr.2016.12.027","article-title":"Optimization Design of Inter-Satellite Link (ISL) Assignment Parameters in GNSS Based on Genetic Algorithm","volume":"60","author":"Huang","year":"2017","journal-title":"Adv. Space Res."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1007\/s10291-018-0704-3","article-title":"Inter-Satellite Communication and Ranging Link Assignment for Navigation Satellite Systems","volume":"22","author":"Sun","year":"2018","journal-title":"GPS Solut."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1007\/s10291-018-0707-0","article-title":"Cascade Optimization Design of Inter-Satellite Link Enhanced with Adaptability in Future GNSS Satellite Networks","volume":"22","author":"Huang","year":"2018","journal-title":"GPS Solut."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1016\/j.asr.2020.09.023","article-title":"A Scheduling Strategy to Inter-Satellite Links Assignment in GNSS","volume":"67","author":"Yan","year":"2021","journal-title":"Adv. Space Res."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1007\/s10291-022-01241-3","article-title":"Topology Design Algorithm for Optical Inter-Satellite Links in Future Navigation Satellite Networks","volume":"26","author":"Zeng","year":"2022","journal-title":"GPS Solut."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"726","DOI":"10.1016\/j.asr.2014.04.020","article-title":"Minimum of PDOP and Its Applications in Inter-Satellite Links (ISL) Establishment of Walker-\u03b4 Constellation","volume":"54","author":"Han","year":"2014","journal-title":"Adv. Space Res."},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Tang, Y., Wang, Y., and Chen, J. (2016). The Availability of Space Service for Inter-Satellite Links in Navigation Constellations. Sensors, 16.","DOI":"10.3390\/s16081327"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"1034","DOI":"10.1016\/j.asr.2012.01.001","article-title":"Autonomous Broadcast Ephemeris Improvement for GNSS Using Inter-Satellite Ranging Measurements","volume":"49","author":"Xu","year":"2012","journal-title":"Adv. Space Res."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1007\/s10291-008-0089-9","article-title":"Characterization of Periodic Variations in the GPS Satellite Clocks","volume":"12","author":"Senior","year":"2008","journal-title":"GPS Solut."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/2011JB008916","article-title":"The Development and Evaluation of the Earth Gravitational Model 2008 (EGM2008)","volume":"117","author":"Pavlis","year":"2012","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_54","unstructured":"Petit, G., and Luzum, B. (2010). IERS Conventions (2010)."},{"key":"ref_55","unstructured":"(2022, November 22). Galileo Satellite Metadata European Union Agency for the Space Programme. Available online: https:\/\/www.gsc-europa.eu\/support-to-developers\/galileo-satellite-metadata."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"775","DOI":"10.1007\/s00190-015-0814-4","article-title":"CODE\u2019s New Solar Radiation Pressure Model for GNSS Orbit Determination","volume":"89","author":"Arnold","year":"2015","journal-title":"J. Geod."},{"key":"ref_57","unstructured":"Zehentner, N. (2016). Kinematic Orbit Positioning Applying the Raw Observation Approach to Observe Time Variable Gravity. [Ph.D. Thesis, Graz University of Technology]."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1007\/s00190-007-0157-x","article-title":"Least-Squares Variance Component Estimation","volume":"82","author":"Teunissen","year":"2008","journal-title":"J. Geod."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"275","DOI":"10.1007\/s00190-015-0872-7","article-title":"Precise Orbit Determination Based on Raw GPS Measurements","volume":"90","author":"Zehentner","year":"2016","journal-title":"J. Geod."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"81","DOI":"10.5194\/adgeo-1-81-2003","article-title":"Noise Variance Estimation and Optimal Weight Determination for GOCE Gravity Recovery","volume":"1","author":"Kusche","year":"2003","journal-title":"Adv. Geosci."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"43","DOI":"10.5081\/jgps.8.1.43","article-title":"Simplified Algorithms of Variance Component Estimation for Static and Kinematic GPS Single Point Positioning","volume":"8","author":"Wang","year":"2009","journal-title":"J. Glob. Position. Syst."},{"key":"ref_62","doi-asserted-by":"crossref","unstructured":"Li, M., Nie, W., Xu, T., Rovira-Garcia, A., Fang, Z., and Xu, G. (2020). Helmert Variance Component Estimation for Multi GNSS Relative Positioning. Sensors, 20.","DOI":"10.3390\/s20030669"},{"key":"ref_63","unstructured":"Zangeneh-Nejad, F., Amiri-Simkooei, A.R., Sharifi, M.A., and Asgari, J. (2017, January 7\u201310). Recursive Least Squares with Real Time Stochastic Modeling: Application to GPS Relative Positioning. Proceedings of the International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences\u2014ISPRS Archives, International Society for Photogrammetry and Remote Sensing: 2017 Tehran\u2019s Joint ISPRS Conferences of GI Research, SMPR and EOEC 2017, Tehran, Iran."},{"key":"ref_64","unstructured":"B\u00e4hr, H., Altamimi, Z., and Heck, B. (2007). Variance Component Estimation for Combination of Terrestrial Reference Frames, Universit\u00e4t Karlsruhe (TH). Schriftenreihe des Studiengangs Geod\u00e4sie und Geoinformatik, Studiengang Geod\u00e4sie und Geoinformatik."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"1285","DOI":"10.1007\/s00190-018-1119-1","article-title":"Parameter Estimation in 3D Affine and Similarity Transformation: Implementation of Variance Component Estimation","volume":"92","year":"2018","journal-title":"J. Geod."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1109\/ISDEA.2010.82","article-title":"A Maneuvered GEO Satellite Orbit Determination Using Robustly Adaptive Kalman Filter","volume":"Volume 1","author":"Xu","year":"2010","journal-title":"Proceedings of the 2010 International Conference on Intelligent System Design and Engineering Application, ISDEA 2010"},{"key":"ref_67","doi-asserted-by":"crossref","unstructured":"Amiri-Simkooei, A.R. (2007). Least-Squares Variance Component Estimation: Theory and GPS Applications. [Ph.D. Thesis, Delft University of Technology].","DOI":"10.54419\/fz6c1c"},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1007\/s10291-008-0110-3","article-title":"Kalman-Filter-Based GPS Clock Estimation for near Real-Time Positioning","volume":"13","author":"Hauschild","year":"2009","journal-title":"GPS Solut."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1007\/s10291-014-0390-8","article-title":"Broadcast versus Precise Ephemerides: A Multi-GNSS Perspective","volume":"19","author":"Montenbruck","year":"2015","journal-title":"GPS Solut."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1007\/s10291-016-0566-5","article-title":"Galileo Status: Orbits, Clocks, and Positioning","volume":"21","author":"Steigenberger","year":"2017","journal-title":"GPS Solut."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/24\/6387\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:43:10Z","timestamp":1760146990000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/24\/6387"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,12,17]]},"references-count":70,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["rs14246387"],"URL":"https:\/\/doi.org\/10.3390\/rs14246387","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2022,12,17]]}}}