Welcome to the Earthdata User Forum! Here, subject matter experts from several NASA Distributed Active Archive Centers (DAAC) can discuss general questions, research needs and data applications. Users can query how to access, view and interpret the data.
The file https://cddis.gsfc.nasa.gov/archive/gnss/data/daily/yyyy/ddd/yyn/brdcddd0.yyn.Z (yyyy is the 4-digit year, ddd is the three-digit day of year and yy is the two-digit year) is the daily broadcast ephemeris file. This file is a merge of the individual site navigation files into one, non-redundant file that can be utilized by users instead of the many individual navigation files. These files are also available in yearly subdirectories of https://cddis.nasa.gov/archive/gnss/data/daily/yyyy/brdc/.