Remote Sensing | |
The Impact of Time Difference between Satellite Overpass and Ground Observation on Cloud Cover Performance Statistics | |
Jᆝrzej S. Bojanowski1  Reto Stཬkli2  Anke Tetzlaff2  Heike Kunz2  Alexander Kokhanovsky2  | |
[1] Federal Office of Meteorology and Climatology MeteoSwiss, Climate Services, Operation Center 1, P.O. Box 257, CH-8058 Zürich-Flughafen, Switzerland; | |
关键词: validation; collocation; SYNOP; AVHRR; sampling error; cloud retrieval; ESA-Cloud-CCI; APCADA; skill score; Hanssen-Kuiper’s discriminant; | |
DOI : 10.3390/rs61212866 | |
来源: mdpi | |
【 摘 要 】
Cloud property data sets derived from passive sensors onboard the polar orbiting satellites (such as the NOAA’s Advanced Very High Resolution Radiometer) have global coverage and now span a climatological time period. Synoptic surface observations (SYNOP) are often used to characterize the accuracy of satellite-based cloud cover. Infrequent overpasses of polar orbiting satellites combined with the 3- or 6-h SYNOP frequency lead to collocation time differences of up to 3 h. The associated collocation error degrades the cloud cover performance statistics such as the Hanssen-Kuiper’s discriminant (HK) by up to 45%. Limiting the time difference to 10 min, on the other hand, introduces a sampling error due to a lower number of corresponding satellite and SYNOP observations. This error depends on both the length of the validated time series and the SYNOP frequency. The trade-off between collocation and sampling error call for an optimum collocation time difference. It however depends on cloud cover characteristics and SYNOP frequency, and cannot be generalized. Instead, a method is presented to reconstruct the unbiased (true) HK from HK affected by the collocation differences, which significantly (
【 授权许可】
CC BY
© 2014 by the authors; licensee MDPI, Basel, Switzerland.
【 预 览 】
Files | Size | Format | View |
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RO202003190018295ZK.pdf | 3272KB | download |