개발된 표류부이를 활용한 고주파레이다 관측평가

Abstract

To verify accuracy of HF Radar, most researchers have compared between velocities measured by HF radar and Current meters(ADCP, RCM, ect). However, comparisons of HF Radar current velocities with current meters in situ are difficult to interpret. Because HF Radars measure depth averaged current of 0~2m for using radar frequency(5~48Mhz) while current meters measure current at one point and deeper than measure depth of HF radar. Therefore, we newly designed GPS-drifters which track the mean current at a depth of about 1-meter to assess of HF radar current velocities. This drifter is 9-cm diameter and 120-cm length cylinder shape including 50x100cm four-plates as drogue. GPS & Iridium antenna, batteries and integrated ( Tx ,Rx and data storage) device placed inside drifter. The drifter-observed velocity show good agreement with the flow obtained by the 25MHz Sesonde HF radar in the Saemangeum coastal ocean of Yellow sea in August 16-19, 2015. Root-mean-square(RMS) velocity difference obtained 5.66~8.36cm/s and correlation coefficient between HF Radar and drifter is over 0.9.rpret. Because HF Radars measure depth averaged current of 0~2m for using radar frequency(5~48Mhz) while current meters measure current at one point and deeper than measure depth of HF radar. Therefore, we newly designed GPS-drifters which track the mean current at a depth of about 1-meter to assess of HF radar current velocities. This drifter is 9-cm diameter and 120-cm length cylinder shape including 50x100cm four-plates as drogue. GPS & Iridium antenna, batteries and integrated ( Tx ,Rx and data storage) device placed inside drifter. The drifter-observed velocity show good agreement with the flow obtained by the 25MHz Sesonde HF radar in the Saemangeum coastal ocean of Yellow sea in August 16-19, 2015. Root-mean-square(RMS) velocity difference obtained 5.66~8.36cm/s and correlation coefficient between HF Radar and drifter is over 0.9.