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
199639707
199748415
199859998
199966591
200092745
200183971
2002100116
2003114211
2004120046
2005123858
2006133900
2007137069
2008140747
2009147428
2010160155
2011171492
2012243382
2013276059
2014347608
2015330465
2016411703
2017189273
2018258685
2019287037
2020248497
2021195724
2022244864
2023229145
2024211914
2025192484
2026102145