Preliminary Study On The Applicability Of Current Field Of High Frequency Ground Wave Radar In Taiwan Strait

This paper uses the Array and Portable High Frequency Ground Wave Radar on the south of FuJian Coast to detect current in the southwest of Taiwan Strait.Harmonic analysis Comparison is made with current measured by buoy A,B,C and D in this region from January 29,2013 to February 28.We draw these Conclusions:The Array High Frequency Ground Wave Radar has a small error of tide ellipse compared with buoy at point A,Band C.While the error of the Portable High Frequency Ground Wave Radar is small at the point A,but larger at remaining buoy points.Also,this paper uses the Astronomical Tide Numerical Model established suitable for the Taiwan Strait to simulate the tide current in Taiwan Strait.Harmonic analysis of the simulating tide current was carried out to compare with the buoy.The result is good,which indicates that the Astronomical Tide Numerical Model can accurately simulate the tide current of Taiwan Strait.In conclusion,the Astronomical Tide Numerical Model is used to simulate the tide current field from 116 °E to 121 0 E,22.4 ° N to 26 ° N,at the same time we use HFGWR to detect current field,both for harmonic analysis to compare tide ellipse,which shows the Array High Frequency Ground Wave Radar has better performance,the tide ellipse are anatomized with the model.While the Portable High Frequency Ground Wave Radar performs well in the area near buoy point A,B,but not well in the rest of points.We firstly superpose astronomical tide current field calculated by model with residual current field interpolated by residual current at buoy points to get simulated-measured current field to compare it with current detected by High Frequency Ground Wave Radar.Firstly,we use current measured by buoy,eliminating M2 tide current to get residual current.The internal residual current field is interpolated by residual current at buoy points,and which is superposed with astronomical tide current field calculated by model to get simulated-measured current field.We compare it with current measured by buoy,the east and north component errors are less than 5 cm/s,which proves that the simulated-measured current field is accurate.Next,we compare the simulated-measured current field with current field detected by the Array High Frequency Ground Wave Radar and the Portable High Frequency Ground Wave Radar,the results are as follows:In the region with calculating residual current of the Portable High Frequency Ground Wave Radar,at 90 ° with two radar station near the central normal area,radar detecting current velocity and direction has minimum mean absolute error,minimum velocity error is 6.7 cm/s,minimum direction error is 17~,error increases extending from this area to periphery,maximum velocity error is 12.1 cm/s,maximum direction error is 32.1 0.Analyse shows the space distribution function Ri of mean absolute error of current velocity(cm/s)and the space distribution function R2 of mean absolute error of current direction(°):R?20-0.164D,-0.216D2 +0.00236D12-0.00165D,D2 +0.00223D22R2 =54-0.750D-0.088D2 +0.0068D12-0.0041DID2 +0.0023D22D1,D2 represents the distance from DongShan and LongHai.In the region with calculating residual current of the Portable High Frequency Ground Wave Radar,at 90 °with two radar station near the central normal area,radar detecting current velocity has minimum mean absolute error(=8.5 crm/s),error increases extending from this area to periphery,the biggest mean absolute error is 24.1 cm/s.Analyse shows the space distribution function Rs of mean absolute error of current velocity(cm/s):R3 =9 + 0.215D3-0.1278D,+0.00087D32-0.00128D,D4 +0.00118D,2D3,D4 represents the distance from ShanLiao and XiaAn.The error distribution of current direction has no certain regularity,and the mean absolute error is large in this region,which is about 100 °...