TROPOSPHERIC PRODUCTS FROM Nevada Geodetic Lab (NGL) WARNING: Due to a formatting error in the tropo SINEX files, the two tropospheric gradient columns (TGNTOT and TGETOT) are interchanged, as are the formal error columns (_SIG). March 26, 2020 Note: As of November 2019, tropospheric products are generated using more advanced modeling and data processing than before. For the first time, NGL products now include integrated water vapor (at zenith) and weighted mean tropospheric temperature (from VMF1 gridded numerical weather model data). NGL now provides over 46,000,000 station-days of tropospheric products (total zenith delay, north gradient, east gradient, water vapor, and weighted mean temperature) every 5 minutes since 1994.0 from over 18,600 stations. These are generated using JPL's GipsyX 1.0 software, JPL's Repro 3.0 orbits and clocks, and VMF1 gridded data and mapping function parameters. The files are available here: http://geodesy.unr.edu/gps_timeseries/trop/ In each 4-character station directory are ZIP files for each year. Unzipping these files produces tropospheric product files for each day of the year. Files are compressed using gzip, generally follow the IGS standard. Please see the IGS SINEX Tropo format at the IGS Central Bureau for more information: ftp://igs.org/pub/data/format/sinex_tropo.txt File names tell you the site name, year, and day of year, for example, P138.2018.294.trop.gz If you have not used IGS SINEX tropo format before, a single-line Linux command can parse out the troposphere data into text columns, e.g., zgrep -A1000 -m1 '^[+-]TROP/SOLUTION' P138.2018.294.trop.gz | tail -n+3 which should give 288 lines (5-minute epochs) of output. This command extracts the block of data between lines starting with +TROP/SOLUTION and -TROP/SOLUTION, while cutting out the header (using tail). The columns descriptions can be found as comments in the files themselves, as well as in a machine-readable SINEX metadata block. These files will be updated weekly with new incoming data, as well as newly discovered stations (~1000 new stations per year). Your comments and advice are appreciated. Geoff Blewitt Nevada Geodetic Lab