1007-4619（2014）01-0206-09Journal of Ｒemote Sensing 遥感学报
Validation and calibration of significant wave
height from HY-2satellite altimeter
XU Guangjun ，YANG Jingsong ，XU Yuan ，PAN Yufang ，CHEN Xiaoyan
State Key Laboratory of Satellite Ocean Environment Dynamics ，Second Institute of Oceanography ，
SOA ，Hangzhou 310012，China
Abstract ：The HY-2，which was launched on August 16，2011，is the first microwave marine remote sensing satellite developed
by China．In this paper ，the data of Significant Wave Height （SWH ）measured by satellite altimeter HY-2were compared with the
data observed by satellite altimeter Jason-1and Jason-2as well as the data measured by buoys．It was found that there was a s
ystematic error of 0．3—0．4m between SWH obtained from HY-2and other altimeters and buoys．The comparison indicated that
there was a linear relationship between the data of HY-2and buoys ，which could be used to calibrate SWH measured by HY-2to better reflect the real marine situation．Comparisons show that the results are good and HY-2altimetry data work well with other
satellite altimetry data．Key words ：HY-2，satellite altimetry ，Significant Wave Height （SWH ），data correction
CLC number ：P715．6Document code ：A
Citation format ：Xu G J ，Yang J S ，Xu Y ，Pan Y F and Chen X Y．2014．Validation and calibration of significant wave height from
HY-2satellite altimeter．Journal of Ｒemote Sensing ，18（1）：206－214［DOI ：10．11834/jrs．20132260］
Ｒeceived ：2012-09-20；Accepted ：2013-08-06；Version of record first published ：2013-08-13
Foundation ：National High Technology Ｒesearch and Development Project （863Project ）（No．2013AA09A505）；China Manned Space Engineering Project ；The Youth Marine Science Foundation of State Oceanic Administration （No．2013445）；The Scientific Ｒesearch Fund of the Second Institute of Oceanography Oce-anography ，State Oceanic Administration of China （No．JG1215）．
First author biography ：XU Guangjun （1987—），male ，master ，he majors in the microwave remote sensing of ocean．E-mail ：gjxu@sio．org．cn
Corresponding author biography ：YANG Jingsong （1969—），male ，professor ，his research interest is the microwave remote sensing of ocean．E-mail ：j
syang@sio．org．cn
1INTＲODUCTION
Satellite altimeter is an active microwave sensor ，which can directly measure the distance from the sea surface．Sea wind speed and Significant Wave Height （SWH ）can be extracted from the echo signal．Compared with the traditional observation ，the advantage of altimeter is that it can work without the effect of weather and with high repetition rates ，wide range and low cost．With the continuous improvement of the data accuracy ，altimeter data are widely used in almost all areas of the physical oceanog-raphy．Altimeter is considered to be one of the most effective and potential satellite sensors．（He ，et al．，2002；Yu ，et al．，2006）
HY-2satellite is the first ocean dynamic environment satel-lite developed by China to access the global ocean dynamic envi-ronment parameters．HY-2Satellite was launched on August 16，
2011and put into trial operation on March 2，2012，continuous-ly achieving observations on sea surface wind ，wave ，height and temperature all-time and all-weather with high data accuracy．
Stable operation and continuous data complement the lack of d omestic and international microwave remote sensing data ，pla-ying an irreplaceable role in the global earth observation s ystem．In this paper ，SWH data from Jason-1and Jason-2satellite
altimeter and buoy are respectively used to compare with SWH
data from HY-2，
verifying the validity of the SWH data from HY-2and its calibration．
2DATA
The validation of SWH data from HY-2is studied in the
worldwide ocean．SWH data used in the present study include
the following observational data ：HY-2data with the repetition period of 14d obtained from National Satellite Ocean Application
Service （NSOAS ），Jason-1and Jason-2data with the repetition
period of 10d downloaded from National Aeronautics and Space Administration （NASA ）and buoy data from National Data Buoy Center （NDBC ）．Table 1shows the main parameters of the sat-ellite altimeters．
Table 1
Main parameters of the satellite altimeters
Satellite Launch time Inclination /
（ʎ）Ｒepetition period /d Orbital altitude /km
Frequency /GHz HY-22011-08-1699．3149715．3/13．6Jason-12001-12-0766*******．3/13．5Jason-2
2008-06-20
66
10
1336
5．3/13．6
Valid SWH data are ，respectively ，filtered from HY-2and
Jason-1/2satellite altimeter according to their handbooks （［2009－07－20］http ：//www．aviso．oceanobs．com /fileadmin /docu-ments /data /tools /hdbk_j1_gdr．pdf ；［2011－03－16］http ：//
