1. Ground-Based Global Navigation Satellite System Observation Summary Data (30-second sampling, daily files) from NASA CDDIS
  2. temporal
YearFile Count
199214838
199324076
199420289
199525727
199639344
199748025
199859330
199965693
200092137
200183678
200299611
2003113913
2004118782
2005123557
2006133571
2007136472
2008139678
2009146474
2010159066
2011170401
2012242290
2013274966
2014346533
2015329897
2016410790
2017188553
2018257629
2019282255
2020243726
2021192679
2022240762
2023222145
202462323