Dunhuang

This site was operational radiometric calibration and validation for Chinese satellite sensors in 2001, and located on the east edge of the Kumutage Penniform Desert in Gansu province, South-West China. It is a Gobi desert, and about 35 km west
the city of Dunhuang . The whole target area for vicarious calibration is situated on a stabilised alluvial fan, 30 km x 30 km size. The area used for high spatial sensors (such as CBERS, TM etal) vicarious calibration measurements is approximately 400 m x 400 m in the centre of the fan and the surface comprises cemented gravels, and 15km×15km for low spatial sensors (Such as NOAA/AVHRR, FY-1/FY-3 optical imagers and EOS/MODIS etal ) vicarious calibration with no vegetation.

 

Sources of meteorological data for the site include the Dunhuang-PAM automated weather station, which is part of the Asian Automatic Weather Station Network. Atmospheric aerosols over the site are typical of a rural continental location, although some larger particles were observed, possibly influx from the sand dunes to the north-west. Sandstorms affect the site on around 8 days per annum and atmospheric dust is a significant factor on around 60 days per annum. [1]

It is one of the CEOS LANDNET Sites. The site is managed by NSMC/CMA; for more detailed information regarding the site, the point of contact is Xiuqing Hu (huxq@cma.gov.cn)

Instruments on the Test Site

ASD field spectroradimeter (350-2500nm)

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Climatological Data for Dunhuang

Parameter Mean Std Dev Min Max Max-Min (Max-Min)/Mean CV
Cloud Fraction (%) 0.4080 0.1247 0.1830 0.5964 0.4134 1.0132 0.3055
Water Vapour Content (g/cm2) 0.8692 0.6696 0.2490 2.1530 1.9040 2.1906 0.7704
Precipitation (mm/day)  0.1836  0.1988  0.0075  0.6511 0.6436 3.5059 1.0827
Ozone Content (Dobson) 316.7750 24.2629 289.0000 349.1000 60.1000 0.1897 0.0766

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Temporal Variability of Cloud Fraction: on the X axis scale is one year (Jan-Dec); on the Y axis scale is the fraction 0-1
Temporal Variability of Water Vapour Content: X axis scale is one year (Jan-Dec); Y axis scale is 0-6 g/cm2
Temporal Variability of Precipitation. X axis scale is one year (Jan-Dec); Y axis scale is 0-10 mm/day
Temporal Variability of Ozone Content. X axis is one year (Jan-Dec); Y axis is 0-500 Dobson
Spectral Temporal Variability  

 

Literature

 

Links

 

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View LANDNET SITES in a larger map

 References

[1] NCAVEO - Dunhuang Page

[2] WP230 - Site Characterization from Climatological Dataset

[3] QA4EO Document - QA4EO-WGCV-IVO-CSP-002 - PDF