71 days simulations (GPS days 2025-01-01 to 2025-03-12)
=======================================================
GNSS constellation (GPS/GALILEO)
- Simulation based on IGS final/COD final orbits
- COD MGEX 5s clock solution used
- PCO/PCV: igs20.atx (applied for Code and Phase)
- without Code/Phase bias
Files: (Tried to follow IGS filename conventions)
attitude/: 5s ORBEX format
clocks/:   5s clock rinex format
orbit/:    5m SP3c format (TRF, CoM correction for ocean tides applied)


RINEX observations
rinex/: RINEX 4.0  (Complete GPS days 5s sampling)
filename convention: D11-PSD_v1.0_Clean.pdf
<MMM>_<CCCC>_<FFF><DDDDDDD>_<YYYYMMDDTHHMMSS>_<YYYYMMDDTHHMMSS>_<vvvv>.rnx.gz
with <MMM>     = NGN
     <CCCC>    = NEES
     <FFF>     = L1B
     <DDDDDDD> = _RINEXz (z = A/B)
     <YYYYMMDDTHHMMSS> = Start/End Time in UTC (corresponds to GPS 0:00 to 0:00 next day)
     <vvvv>    = 0000 (version)

NGGM Metadata:
- Antenna Reference Point (ARP): (x=0, y=0, z=-0.5m) in nadir pointing SRF
- Zero Phase Center Offsets (ARP=L1=L2=L5), without phase center variations (PCV)
- without Code/Phase bias

miscellaneous:
- Code/Phase observations
      GPS: L1C L1W L2W L2L C1C C1W C2L C2W
      GALILEO: L1C L5Q C1C C5Q
- without SNR information (not yet included in GROOPS).
- without observation noise/clock noise
- simulated integer ambiguities
- usual effects/corrections included
    -- phase windup
    -- Ionosphere (first order only, based on IGS final VTEC maps)
    -- relativistic clock and space time
- Earth rotation:
  https://datacenter.iers.org/products/eop/rapid/standard/finals2000A.all
  (IERS conventions + high frequent Desai model (desai_model_jgrb51665-sup-0002-ds01.txt)