separate reflection. This is called the clutter load. Clutter is reduced over the surface of the open ocean far from land. A large number of reflections will overwhelm computing systems and humans. The typical solution is to limit the main lobe of the antenna beam so that it does not point near the ground. This is called the low-elevation limit. This creates a blind zone that can be exploited using nap-of-the-earth flying techniques to avoid detection. Weather phenomenon increases the low-elevation of the radar system. Moving target indication (MTI) is used to improve the low-elevation limit. MTI creates blind velocities associated with radar scalloping. This reduces radar sensitivity at certain radial velocities, but MTI allows the main lobe of the antenna beam to be aimed closer to the ground. Wind speed above about 5 mile/hour moves debris fast enough to create excessive clutter load, which eliminates most of the MTI improvement. Bearing coverage Bearing coverage of a radar is determined by any nearby obstructions that may interfere with the radar antenna. On ships, this could be caused by the mast. On land, this could be caused by buildings or terrain. Sidelobe performance Reflections from large objects and stray electronic emissions may enter the radar antenna from a sidelobe. This degrades performance for nearby objects. Sidelobe suppression strategies are sometimes used to improve this measure of performance. References Radar