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
199525734
199639708
199748415
199859998
199966597
200092746
200183973
2002100117
2003114289
2004120404
2005124218
2006134318
2007137177
2008140869
2009147449
2010160166
2011171493
2012243387
2013276062
2014347639
2015330836
2016412055
2017190471
2018259429
2019287823
2020249378
2021196601
2022245640
2023229510
2024212675
2025193288
2026187923