INTRODUCTION TO COASTAL HF MARITIME SURVEILLANCE RADARS

This paper presents the main technical characteristics and working performances of coastal maritime surveillance radars, such as low-power D-3 High-Frequency Surface Wave Radars (HFSWR) and Over the Horizon Radars (OTHR).These radars have demonstrated to be a cost-effective long-range early-warning sensor for ship detection and tracking in coastal

The classification of hidden dangers in urban gas pipelines plays a vital role in the smooth operation of urban gas pipelines and in solving the problem of hidden safety dangers in urban gas pipelines.In recent years, the number and proportion of polyethylene (PE) pipelines in urban gas pipelines are increasing day by day, but the current classific