Genesis GPS Occultation Observations Level 1A provides atmospheric phase delay and signal amplitude data from low-earth-orbit satellites. Data originates from CHAMP and SAC-C satellites carrying JPL Blackjack GPS receivers, with over 200 occultation events recorded globally per day per satellite. The dataset is produced by the SCIOPS organization for deriving atmospheric profiles.
Use Cases
- Compute atmospheric refractivity profiles from phase delay measurements at 1.2 and 1.6 GHz frequencies.
- Derive temperature and pressure profiles between 60 km and the troposphere by inverting phase delay data.
- Estimate water vapor density in the lower troposphere using phase delay data combined with independent temperature knowledge.
- Analyze signal amplitude variation for physical optics inversion to account for diffraction effects.
- Validate global weather model outputs from NCEP and ECMWF using occultation-derived temperature profiles.
Strengths
- Data offers sub-kilometer vertical resolution for atmospheric profiling.
- Temperature accuracy is sub-Kelvin below 45 km altitude.
- Over 200 globally distributed occultation events are recorded per satellite daily.
- Phase delay data is available at a high time resolution of 0.01 or 0.02 seconds for the 1.6 GHz frequency.
Limitations
- The specific row count, file size, and temporal coverage range are not provided.
- Data relies on the assumption of local spherical symmetry about the tangent point for inversion.
- The forward-facing antenna on the SAC-C satellite is noted as inactive, potentially reducing data collection points.
Provenance
- Source
- SCIOPS organization, utilizing data from GFZ's CHAMP and CONAE's SAC-C satellites.
- Collection Method
- Radio occultation measurements from LEO satellites carrying JPL Blackjack GPS receivers, recording signals from GPS satellites setting behind Earth's limb.
- Time Range
- null
- Freshness
- null
- Geography
- Global coverage with fairly uniform distribution from satellite orbits.