{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:21:04Z","timestamp":1760235664470,"version":"build-2065373602"},"reference-count":32,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2021,9,10]],"date-time":"2021-09-10T00:00:00Z","timestamp":1631232000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000844","name":"European Space Agency","doi-asserted-by":"publisher","award":["4000128661\/19\/NL\/SC"],"award-info":[{"award-number":["4000128661\/19\/NL\/SC"]}],"id":[{"id":"10.13039\/501100000844","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The main objective of the present study is to perform an analysis of the space weather impact on the Latvian CORS (Continuously Operating GNSS (Global Navigation Satellite System) Stations) GPS (Global Positioning System) observations, in situations of geomagnetic storms, sun flares and extreme TEC (Total Electron Content) and ROTI (Rate of change of TEC index) levels, by analyzing the results, i.e., 90-s kinematic post-processing solutions, obtained using Bernese GNSS Software v5.2. To complete this study, the 90-s kinematic time series of all the Latvian CORS for the period from 2007 to 2017 were analyzed, and a correlation between time series outliers (hereinafter referred to as faults) and extreme space weather events was sought. Over 36 million position determination solutions were examined, 0.6% of the solutions appear to be erroneous, 0.13% of the solutions have errors greater than 1 m, 0.05% have errors greater than 10 m, and 0.01% of the solutions show errors greater than 50 m. The correlation between faulty results, TEC and ROTI levels and Bernese GNSS Software v5.2 detected cycle slips was computed. This also includes an analysis of fault distribution depending on the geomagnetic latitude as well as faults distribution simultaneously occurring in some stations, etc. This work is the statistical analysis of the Latvian CORS security, mainly focusing on geomagnetic extreme events and ionospheric scintillations in the region of Latvia, with a latitude around 57\u00b0N.<\/jats:p>","DOI":"10.3390\/rs13183624","type":"journal-article","created":{"date-parts":[[2021,9,12]],"date-time":"2021-09-12T21:48:01Z","timestamp":1631483281000},"page":"3624","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Extreme Solar Events\u2019 Impact on GPS Positioning Results"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3670-964X","authenticated-orcid":false,"given":"Janis","family":"Balodis","sequence":"first","affiliation":[{"name":"Institute of Geodesy and Geoinformatics, University of Latvia, Jelgavas 3, LV-1004 Riga, Latvia"}]},{"given":"Madara","family":"Normand","sequence":"additional","affiliation":[{"name":"Institute of Geodesy and Geoinformatics, University of Latvia, Jelgavas 3, LV-1004 Riga, Latvia"}]},{"given":"Inese","family":"Varna","sequence":"additional","affiliation":[{"name":"Institute of Geodesy and Geoinformatics, University of Latvia, Jelgavas 3, LV-1004 Riga, Latvia"}]}],"member":"1968","published-online":{"date-parts":[[2021,9,10]]},"reference":[{"key":"ref_1","unstructured":"Dunbar, B. (2020, November 03). Space Weather. National Aeronautics and Space Administration, Available online: https:\/\/www.nasa.gov\/mission_pages\/rbsp\/science\/rbsp-spaceweather.html."},{"key":"ref_2","unstructured":"National Science & Technology Council, and United States Government (2020, November 03). National Space Weather Strategy and Action Plan. White House Archives, Available online: https:\/\/trumpwhitehouse.archives.gov\/wp-content\/uploads\/2019\/03\/National-Space-Weather-Strategy-and-Action-Plan-2019.pdf."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"A22","DOI":"10.1051\/swsc\/2014020","article-title":"Scintillations of the GPS, GLONASS, and Galileo signals at equatorial latitude","volume":"4","author":"Hlubek","year":"2014","journal-title":"J. Space Weather Space Clim."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3429","DOI":"10.5194\/angeo-27-3429-2009","article-title":"Climatology of GPS ionospheric scintillations over high and mid-latitude European regions","volume":"27","author":"Spogli","year":"2009","journal-title":"Ann. Geophys."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1314","DOI":"10.1016\/j.asr.2008.12.012","article-title":"Transionospheric GPS signal delay gradients ob-served over mid-latitude Europe during the geomagnetic storms of October\u2013November 2003","volume":"43","author":"Stankov","year":"2009","journal-title":"Adv. Space Res."},{"key":"ref_6","unstructured":"Mayer, C., Belabbas, B., and Dunkel, W. (2020, November 02). Ionospheric Threat Model Assessment. ICAO NSP Meeting, EUROCONTROL Experimental Centre. Available online: https:\/\/elib.dlr.de\/58489\/."},{"key":"ref_7","unstructured":"Circiu, M.-S., Felux, M., Remi, P., Yi, L., Belabbas, B., and Pullen, S. (2014, January 27\u201329). Evaluation of Dual Frequency GBAS Performance Using Flight Data. Proceedings of the 2014 International Technical Meeting of The Institute of Navigation, San Diego, CA, USA."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Lee, J., and Lee, J. (2019). Correlation between ionospheric spatial decorrelation and space weather in-tensity for safety-critical differential GNSS systems. Sensors, 19.","DOI":"10.3390\/s19092127"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Liu, X., Yuan, Y., Tan, B., and Li, M. (2016). Observational Analysis of Variation Characteristics of GPS-Based TEC Fluctuation over China. ISPRS Int. J. Geo-Inf., 5.","DOI":"10.3390\/ijgi5120237"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"585","DOI":"10.1002\/2015SW001237","article-title":"Dynamics of the high-latitude ionospheric ir-regularities during the 17 March 2015 St. Patrick\u2019s Day storm: Ground-based GPS measurements","volume":"13","author":"Cherniak","year":"2015","journal-title":"Space Weather"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2516","DOI":"10.1029\/2020SW002516","article-title":"Variations of TEC Over Iberian Peninsula in 2015 Due to Geomagnetic Storms and Solar Flares","volume":"18","author":"Morozova","year":"2020","journal-title":"Space Weather"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"9023","DOI":"10.1002\/2015JA021629","article-title":"Ionospheric response to the 2015 St. Patrick\u2019s Day storm: A global multi-instrumental overview","volume":"120","author":"Astafyeva","year":"2015","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"A9","DOI":"10.1051\/swsc\/2016004","article-title":"Overview of the 2015 St. Patrick\u2019s day storm and its consequences for RTK and PPP positioning in Norway","volume":"6","author":"Jacobsen","year":"2016","journal-title":"J. Space Weather Space Clim."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"727","DOI":"10.1002\/2015JA021832","article-title":"Profiles of ionospheric storm-enhanced density during the 17 March 2015 great storm","volume":"121","author":"Liu","year":"2016","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"20180098","DOI":"10.1098\/rsta.2018.0098","article-title":"Ionospheric response to solar and interplane-tary disturbances: A Swarm perspective","volume":"377","author":"Balasis","year":"2019","journal-title":"Philos. Trans. R. Soc. A Math. Phys. Eng. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1029\/2006SW000260","article-title":"GPS and ionospheric scintillations","volume":"5","author":"Kintner","year":"2007","journal-title":"Space Weather"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1198","DOI":"10.1109\/LGRS.2019.2941643","article-title":"GNSS and SAR Signal Delay in Perturbed Ionospheric D-Region during So-lar X-Ray Flares","volume":"17","author":"Nina","year":"2020","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1262","DOI":"10.1029\/2018JA026063","article-title":"Ionospheric Plasma Irregularities Characterized by the Swarm Satellites: Statistics at High Latitudes","volume":"124","author":"Jin","year":"2019","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1338","DOI":"10.1002\/2016JA023086","article-title":"Morphology of high-latitude plasma density perturbations as deduced from the total electron content measurements onboard the Swarm constellation","volume":"122","author":"Park","year":"2017","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1186\/s40562-016-0057-0","article-title":"Impact and mitigation of space weather effects on GNSS receiver performance","volume":"3","author":"Sreeja","year":"2016","journal-title":"Geosci. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1007\/s10291-019-0902-7","article-title":"Regional integration of long-term national dense GNSS network solutions","volume":"23","author":"Kenyeres","year":"2019","journal-title":"GPS Solut."},{"key":"ref_22","unstructured":"Dach, R., Lutz, S., Walser, P., and Fridez, P. (2015). Bernese GNSS Software Version 5.2, University of Bern, Bern Open Publishing."},{"key":"ref_23","unstructured":"(2021, August 09). CODE Data Archive. Available online: ftp:\/\/ftp.unibe.ch\/aiub\/BSWUSER50\/ATM\/."},{"key":"ref_24","unstructured":"(2021, August 09). Real-Time Auroral and Solar Activity. Available online: https:\/\/www.spaceweatherlive.com\/."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Julien, O., Selmi, I., Pagot, J.-B., Samson, J., and Fernandez, F.A. (February, January 30). Extension of EWF Threat Model and Associated SQM. Proceedings of the 2017 International Technical Meeting of The Institute of Navigation, Monterey, CA, USA.","DOI":"10.33012\/2017.14873"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Leick, A., Rapoport, L., and Tatarnikov, D. (2015). GPS Satellite Surveying, Wiley. [4th ed.].","DOI":"10.1002\/9781119018612"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2283","DOI":"10.1029\/97GL02273","article-title":"Monitoring of global ionospheric irreg-ularities using the worldwide GPS network","volume":"24","author":"Pi","year":"1997","journal-title":"Geophys. Res. Lett."},{"key":"ref_28","unstructured":"(2021, June 14). CDDIS Data Archive, Available online: https:\/\/cddis.nasa.gov\/archive\/gnss\/products\/ionex\/."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Morozova, K., J\u00e4ger, R., Zarins, A., Balodis, J., Varna, I., and Silabriedis, G. (2021). Evaluation of quasigeoid model based on astrogeodetic measurements: Case of Latvia. J. Appl. Geod.","DOI":"10.1515\/jag-2021-0030"},{"key":"ref_30","unstructured":"Wautelet, G. (2013). Characterization of Ionospheric Irregularities and Their Influence on High-Accuracy Positioning with GPS over Mid-Latitudes. [Ph.D. Thesis, Universit\u00e9 de Li\u00e8ge]."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"163","DOI":"10.5194\/angeo-31-163-2013","article-title":"GPS observations of medium-scale traveling ionospheric disturbances over Europe","volume":"31","author":"Otsuka","year":"2013","journal-title":"Ann. Geophys."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"A9","DOI":"10.1029\/2011JA016545","article-title":"Climatology of medium-scale traveling ionospheric disturbances observed by a GPS network in central China","volume":"116","author":"Ding","year":"2011","journal-title":"J. Geophys. Res. Space Phys."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/18\/3624\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:00:48Z","timestamp":1760166048000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/18\/3624"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,9,10]]},"references-count":32,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2021,9]]}},"alternative-id":["rs13183624"],"URL":"https:\/\/doi.org\/10.3390\/rs13183624","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2021,9,10]]}}}