Preliminary validation of the refractivity from the new radio occultation sounder GNOS/FY-3C
As a new member of the space-based radio occultation sounders, the GNOS (Global Navigation Satellite System Occultation Sounder) mounted on Fengyun-3C (FY-3C) has been carrying out atmospheric sounding since 23 September 2013. GNOS takes approximately 800 daily measurements using GPS (Global Positio...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-03-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | http://www.atmos-meas-tech.net/9/781/2016/amt-9-781-2016.pdf |
| Summary: | As a new member of the space-based radio occultation sounders, the GNOS
(Global Navigation Satellite System Occultation Sounder) mounted on
Fengyun-3C (FY-3C) has been carrying out atmospheric sounding since 23 September 2013. GNOS takes approximately 800 daily measurements using GPS
(Global Positioning System) and Chinese BDS (BeiDou navigation satellite)
signals. In this work, the atmospheric refractivity profiles from GNOS were
compared with the ones obtained from the co-located ECMWF (European Centre
for Medium-Range Weather Forecasts) reanalysis. The mean bias of the
refractivity obtained through GNOS GPS (BDS) was found to be approximately
−0.09 % (−0.04 %) from the near surface to up to 46 km. While the average
standard deviation was approximately 1.81 % (1.26 %), it was as low as
0.75 % (0.53 %) in the range of 5–25 km, where best sounding results
are usually achieved. Further, COSMIC (Constellation Observing System for
Meteorology, Ionosphere and Climate) and MetOp/ GRAS (GNSS Receiver for
Atmospheric Sounding) radio occultation data were compared with the ECMWF
reanalysis; the results thus obtained could be used as reference data for
GNOS. Our results showed that GNOS/FY-3C meets the design requirements in
terms of accuracy and precision of the sounder. It possesses a sounding
capability similar to COSMIC and MetOp/GRAS in the vertical range of 0–30 km,
though it needs further improvement above 30 km. Overall, it provides a
new data source for the global numerical weather prediction (NWP) community. |
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| ISSN: | 1867-1381 1867-8548 |