Surface transport detected by pairs of COSMO-SkyMed ScanSAR images in the Qingdao region (Yellow Sea) during a macro-algal bloom in July 2008

In early summer 2008 an extended macro-algal bloom in the Qingdao coastal area caused the presence of huge algal aggregates at the sea surface clearly visible in SAR images. The event was observed by WideRegion ScanSAR data (X-band) acquired in July 2008 by the two currently operative COSMO-SkyMed satellites.The current constellation (two of four satellites operative by 2010) provides pairs of overlapping images with a time shift of 48 min, with a repeat time from 12 to 24 h. The full constellation will allow a peak daily acquisition capability of 24 min in the ScanSAR mode. The double acquisition with a short time lag, similar to a time derivative in the overlapping area, allows an accurate ‘feature tracking’ and automated extraction of the surface transport not previously available. Considering that SAR images are unaffected by cloud cover, accurate surface transport patterns greatly improve the forecasting capability in the case of marine environmental emergencies.