IGS products support scientific activities such as improving and extending the International Terrestrial Reference Frame (ITRF) maintained by the International Earth Rotation and Reference Systems Service (IERS), monitoring deformations of the solid Earth and variations in the liquid Earth (sea level, ice sheets, etc.) and in Earth rotation, determining orbits of scientific satellites, and monitoring the troposphere and ionosphere.
| IGS Product Table [GPS Broadcast values included for comparison] | |||||||
|---|---|---|---|---|---|---|---|
| Accuracy | Latency | Updates | Sample Interval | Archive locations | |||
| GPS Satellite Ephemerides/ Satellite & Station Clocks | |||||||
| Broadcast | orbits | ~160 cm | real time | -- | daily | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) |
|
| Sat. clocks | ~7 ns | ||||||
| Ultra-Rapid (predicted half) | orbits | ~10 cm | real time | four times daily | 15 min | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) IGS CB(US-CA) |
|
| Sat. clocks | ~5 ns | ||||||
| Ultra-Rapid (observed half) | orbits | <5 cm | 3 hours | four times daily | 15 min | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) IGS CB(US-CA) |
|
| Sat. clocks | ~0.2 ns | ||||||
| Rapid | orbits | <5 cm | 17 hours | daily | 15 min | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) IGS CB(US-CA) |
|
| Sat. & Stn. clocks | 0.1 ns | 5 min | |||||
| Final | orbits | <5 cm | ~13 days | weekly | 15 min | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) IGS CB(US-CA) |
|
| Sat. & Stn. clocks | <0.1 ns | 5 min | |||||
| Note 1: IGS accuracy limits, except for predicted orbits, based on comparisons with independent laser ranging results. The precision is better.
Note 2: The accuracy of all clocks is expressed relative to the IGS timescale, which is linearly aligned to GPS time in one-day segments. | |||||||
| GLONASS Satellite Ephemerides | |||||||
| Final | 15 cm | 2 weeks | weekly | 15 min | CDDIS(US-MD) | ||
| IGN(FR) | |||||||
| Geocentric Coordinates of IGS Tracking Stations (>130 sites) | |||||||
| Final positions | horizontal | 3 mm | 12 days | weekly | weekly | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) |
|
| vertical | 6 mm | ||||||
| Final velocities | horizontal | 2 mm/yr | 12 days | weekly | weekly | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) |
|
| vertical | 3 mm/yr | ||||||
| Earth Rotation Parameters: Polar Motion (PM) Polar Motion Rates (PM rate) Length-of-day (LOD) | |||||||
| Ultra-Rapid (predicted half) | PM | 0.3 mas | real time | four times daily | four times daily (00,06,12,18 UTC) | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) IGS CB(US-CA) |
|
| PM rate | 0.5 mas/day | ||||||
| LOD | 0.06 ms | ||||||
| Ultra-Rapid (observed half) | PM | 0.1 mas | 3 hours | four times daily | four times daily (00,06,12,18 UTC) | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) IGS CB(US-CA) |
|
| PM rate | 0.3 mas/day | ||||||
| LOD | 0.03 ms | ||||||
| Rapid | PM | <0.1 mas | 17 hours | daily | daily (12 UTC) | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) IGS CB(US-CA) |
|
| PM rate | <0.2 mas/day | ||||||
| LOD | 0.03 ms | ||||||
| Final | PM | 0.05 mas | ~13 days | weekly | daily (12 UTC) | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) IGS CB(US-CA) |
|
| PM rate | <0.2 mas/day | ||||||
| LOD | 0.02 ms | ||||||
| Note: The IGS uses VLBI results from IERS Bulletin A to calibrate for long-term LOD biases. | |||||||
| Atmospheric Parameters | |||||||
| Final tropospheric zenith path delay | 4 mm | < 4 weeks | weekly | 2 hours | CDDIS(US-MD) SOPAC(US-CA) IGN(FR) | ||
| Ultra-Rapid tropospheric zenith path delay | 6 mm | 2-3 hours | every 3 hours | 1 hour | CDDIS(US-MD) | ||
| Final Ionospheric TEC grid | 2-8 TECU | ~11 days | weekly | 2 hours; 5 deg (lon) x 2.5 deg (lat) |
CDDIS(US-MD) IGN(FR) |
||
| Rapid Ionospheric TEC grid | 2-9 TECU | <24 hours | daily | 2 hours; 5 deg (lon) x 2.5 deg (lat) |
CDDIS(US-MD) IGN(FR) |
||
See which products were most recently released on the product availability page, or view the traditional product summaries for the CB and the Global Data Centers: CDDIS, IGN and SIO.
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