This essential guide introduces boat owners to radar fundamentals, covering everything from reading a radar screen, avoiding collisions, and tracking weather to navigating and piloting using a radar/map display.
Bill Johnson is an engineer and sailor. He has been involved in boating and the sea from an early age. After a career in software engineering, he started Aztec Sailing, which, under his leadership, has provided practical sail training from complete beginner to long-distance ocean cruising for the last 10 years.
1 Introduction. 2 Radar - what it does, and how it works. How radar works Understanding what a radar does. How a radar 'sees'. Getting technical. Measuring distance. Measuring direction. Basic radar picture display. Beam width. Picture stabilization. Where can radar see? What can radar see? Clutter. How radar displays the picture. Conclusion: looking at a radar picture. 3 Basic machine and controls - how to get a good picture. Turning the radar on. Range scale control. Brilliance, or light and contrast. Gain. Tuning. The display. Sea clutter. Rain (precipitation) clutter. Electronic bearing line. Variable range marker. Cursor. 4 How to use radar for collision avoidance. Introduction. Practical approach in reduced visibility. Collision risk. International Regulations for Preventing Collisions at Sea. Plotting. Plotting method. Examples. Automatic target tracking. VHF radio. Automatic Identification System (AIS). 5 How to use radar for navigation and pilotage. Introduction. Which type of display? Comparison between chart and radar picture. Identifying radar targets. Landfall. Radar position lines. Plotting radar position lines. Position fix using radar. Racons (radar beacons). Useful techniques. 6 More radar science - confusion and anomalies. Radar frequency bands. Signal strength and range. Pulse length and pulse repetition frequency. Target expansion. Horizontal beam width. Vertical beam width. Side lobes. Indirect and multiple echoes. Interference from other radars. Refraction and range. 7 Modern radar - more advanced functions. 'Basic' and 'advanced' functionality. Look-ahead / zoom in. Azimuth stabilized display. Target latitude and longitude. Combining radar with navigation information. AIS integration. True motion display: ground stabilized. True motion display: sea stabilized. Signal strength. Dual range display. High speed update. Scan-to-scan correlation. Automatic target tracking. Target wakes (echo trails). Guard zones. Watchman mode. Conclusion. 8 Choosing and installing radar. Safety. Radar power. Scanner size. Scanner weight. Scanner position. Electrical supply and cables. Integration with other instruments. Positioning of display. Conclusion. Glossary/Index. References for further study. Acknowlefgements.