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
2007136780
2008140450
2009147077
2010159792
2011171127
2012243016
2013275694
2014347247
2015330465
2016411513
2017189273
2018258685
2019287037
2020248497
2021195724
2022244864
2023229145
2024211913
2025192173
202667958