|
|
GRM-01: NRT Refractivity Profile (NRP)
 |
| _ | Values | Remarks |
| Units | Refractivity units (N) | _ |
| Domain | 0-50 km | Surface to
~1 hPa |
| Range | 0-450 N-units | _ |
Requirement on
target accuracy | 0-5 km: 0.6%-2%
5-30 km: 0.6%
30-50 km: 0.03 N-units | _ |
Requirement on
vertical resolution | 150-250 m | _ |
| Status | Operational | _ |
Current product version: 1.3
Previous product versions: 1.1, 1.2
(during development phase) | _ |
|
Product description
The NRT refractivity product contains a profile of neutral refractivity as a function of height (geometric and geopotential) above the EGM-96 geoid.
Algorithm description
Each product profile is the result of one radio occultation. Signals from the occulting GPS satellite are measured by the GRAS receiver onboard the EPS/MetOp satellite, downlinked, and processed by the GRAS SAF into refractivity. More details can be found on the Radio Occultation Theory page and in the Validation Report.
Data characteristics
GRAS measures about 700 GPS occultations per day. GRM-01 is output in both NetCDF and BUFR format, and disseminated via GTS/RMDCN (BUFR) and EUMETCast (NetCDF and BUFR). NetCDF files are also stored in the GRAS SAF Product Archive.
Product validation and monitoring
Accuracy of the current version of the product is described in the Validation Report. Daily monitoring of the processing and dissemination can be seen on the Monitoring Page.
Product documentation
All GRAS SAF NRT and Offline products are described in the Product User Manual.
To retrieve this product please go to the Product Archive.
|
