CASSIOPE SPACECRAFT (Swarm-E)
PROCESSED DATA HANDBOOK
GAP Topside Vertical TEC (VTEC) NetCDF File
GAP Vertical TEC (VTEC) files are 24 hour daily files at 1 Hz resolution. Each daily file contains 86400 VTEC values, each of which is derived from measurements from all GAP receivers and all available GPS satellites, with a 10 degree elevation mask applied. VTEC has a value of NaN when no GAP data is available.
The file names are GAP_YYYYMMDD_hhmmss_HHMMSS_VTEC_V.v.r.nc.zip where:
| YYYY | year |
| MM | month |
| DD | day |
| hh | start hour |
| mm | start minute |
| ss | start second |
| HH | end hour |
| MM | end minute |
| SS | end second |
| V | Major code version |
| v | Minor code version |
| r | reprocessing count |
Global Attributes:
| Month (integer) | Month of file |
| Day (integer) | Day of file |
| Year (integer) | Year of file |
| RES (double) | Data time resolution (seconds) |
Variables:
| UT (double) | 1D array of time tags for each Line-of-Sight (LOS) TEC value (hours of UT) |
| VTEC (double) | 1D array of VTEC calculated from combined GAP-A and GAP-O observations (TEC units) |
| VTEC_RMS (double) | 1D array of root-mean-square deviations for each VTEC value (TEC units) |
| NVALUES (integer) | 1D array of number of individual LOSTEC values used to compute each corresponding VTEC value |
| value (#) | Each LOSTEC value is from a particular GAP receiver and GPS satellite. |
| XEPOP(double) | 1D array of ECEF x-component location of CASSIOPE satellite (km) |
| YEPOP(double) | 1D array of ECEF x-component location of CASSIOPE satellite (km) |
| ZEPOP(double) | 1D array of ECEF x-component location of CASSIOPE satellite (km) |