SBASCORR messages (in SBAS processing mode only)

SBAS corrections breakdown. It is shown when a model can be fully computed using SBAS corrections for GPS C1C measurement. All time tags are in GPS time.

Field 1: 'SBASCORR' (if it is used in computation) or 'SBASCORR*' (if it is not) Field 2: Receiver id Field 3: SBAS processing mode (PA or NPA) Field 4: GNSS System (GPS, GAL, GLO or GEO) Field 5: PRN satellite identifier Field 6: Year Field 7: Doy Field 8: Seconds of day Field 9: GPS week Field 10: Time of week Field 11: GEO PRN from which SBAS corrections are used ('0' means all GEOs) Field 12: Measurement-model value (prefit) [m] Field 13: Measurement value without smoothing [m] Field 14: Measurement value with smoothing [m] Field 15: Satellite-receiver geometric distance (with SBAS corrections) [m] Field 16: Relativity correction (with SBAS corrections) [m] Field 17: Satellite clock correction (with SBAS corrections) [m] Field 18: Total Group Delay (TGD) correction [m] Field 19: Ionosphere pierce point latitude [-90..90 degrees] Field 20: Ionosphere pierce point longitude [0..360 degrees] Field 21: Ionosphere correction [m] Field 22: Troposphere nominal correction [m] Field 23: PRC (fast correction) applied to the satellite [m] Field 24: RRC (range-rate correction) applied to the satellite [m] Field 25: Fast correction degradation factor [m/s^2] Field 26: PRC time out [s] Field 27: RRC time out (smallest PRC time out for all satellites) [s] Field 28: Time (seconds of day) used for computing PRC timeout Field 29: Time (seconds of day) used for computing sigma UDRE (User Differential Range Error) timeout

Field 30: Time (seconds of day) used for computing fast correction degradation Field 31: X component of the satellite position in WGS84 system at emission time with SBAS corrections [m] Field 32: Y component of the satellite position in WGS84 system at emission time with SBAS corrections [m] Field 33: Z component of the satellite position in WGS84 system at emission time with SBAS corrections [m] Field 34: Long term correction to be applied to the X component of the satellite [m] Field 35: Long term correction to be applied to the Y component of the satellite [m] Field 36: Long term correction to be applied to the Z component of the satellite [m] Field 37: Long term correction to be applied to the satellite clock [m] Field 38: IODP (Issue of Data PRN mask) used for fast corrections Field 39: IODF (Issue of Data Fast Correction) in messages type 2-5,24 for fast corrections Field 40: Satellite slot in the fast correction mask [1..51] Field 41: IODP used for long term corrections Field 42: Satellite slot in the long term correction mask [1..51] Field 43: IODE (Issue of Data Ephemeris) used for broadcast ephemeris Field 44: IODS (Service Issue of Data) used for service message Field 45: IODP used for covariance matrix Field 46: Satellite slot in the covariance mask [1..51] Field 47: Ionosphere model flag Field 48: Satellite elevation [degrees] Field 49: Satellite azimuth [degrees]

• Sample: SBASCORR vigo PA GPS 23 2015 165 5088.00 1849 5088.00 120 60577.5787 20948474.4600 20948474.4600 20853522.4567 -4.3086 34379.4657 -6.0029 42.7112 -7.1281 2.3087 2.7117 -0.2500 0.0000 0.00580 12.0000 12.0000 5084.1 5084.1 5084.1 17496575.5944 5306168.63534 19563205.09708 -1.00000 0.62500 0.12500 0.69801 0 1 22 0 22 99 0 -1 -1 0 65.512 66.455

- When the '*' appears in field 1, it is due to smoothed code of the satellite has not reached steady-state, a SBAS processing mode switch or SBAS GEO switch. When a mode or GEO switch occurs, the SBAS corrections have to be computed again.
- Field 43 is the IODE value from the broadcast message matched with the SBAS long term corrections. If the field value is negative, it means that the IODE used does not match any SBAS long term correction messagea available (only in NPA mode). A value of 999 means that no valid broadcast message was found for the current epoch.
- Field 47 is a flag to indicate which ionosphere model is used. Its possible values are '-1' for no ionosphere model, '0' for SBAS ionosphere model, '1' for Klobuchar ionosphere model and '2' for any other ionosphere model.