HY-2 has been launched by China on August 16,2011 which assembles multi-microwave remote sensing payloads in a body and has the ability of monitoring ocean dynamic environments.The HY-2 satellite data need to be calibrated and validated before being put into use.Based on the in-situ buoys from the National Data Buoy Center(NDBC),Ku-band significant wave heights(SWH,hs)of HY-2 altimeter are validated.Eleven months of HY-2 altimeter Level 2 products data are chose from October 1,2011 to August 29,2012.Using NDBC 60 buoys yield 902 collocations for HY-2 by adopting collocation criteria of 30 min for temporal window and 50 km for a spatial window.An overall RMS difference of the SWH between HY-2 and buoy data is 0.297 m.A correlation coefficient between these is 0.964.An ordinary least squares(OLS)regression is performed with the buoy data as an independent variable and the altimeter data as a dependent variable.The regression equation of hs is hs(HY-2)=0.891×hs(NDBC)+0.022.In addition,2016 collocations are matched with temporal window of 30 min at the crossing points of HY-2 and Jason-2 orbits.RMS difference of Ku-band SWH between the two data sets is 0.452 m.
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