<title>Improvement of sea-environment sounding technology and signal processing method for HF ground-wave radar</title>

Abstract

In the research of using HF ground wave radar to detect sea environment, we adopt symmetrical Yagi antenna array, correct the influence on antenna beam direction by platform on-sea and sea surface, optimize the schemes in the postprocessing, which include multiple correlation, Bragg-Doppler spectrum identification and reconstruction processing. During the signal gathering, the statistical character of slow sea-state variation is utilized (statistical big wave period about 5s). It facilitates the multiple correlation integration and satisfy the requirement for reconstruction processing. So the reliability of extracting sea echo data and articulation of Bragg-Doppler spectrum are greatly improved. We simulate how platform on-sea (made of Ferro-concrete) and sea surface influence beam direction with scale model. And under varied conditions the rise degree of main beam is measured. These data can help us correct the direction of vertical antenna during practical erecting. With these data, we do the inversion of sea surface flow field and wave field parameters. The result agrees with what the standard scaling machine measure.Company. It is set in the beam direction of 15km (locating by GPS). Comparing to the scaling, the current accuracy is 3 .lcmls, and the wave-height accuracy is 13.5% for SESAR synchronous measurement.Antenna is erected on the platform. The height of it from sea surface is about 714m (that is 0.62 -1.2 2), changing