The maximum distance (Rmax) for radar detection depends to a considerable extent on several factors, such as the height of the antenna above water, the altitude, size, shape, target material, and atmospheric conditions of the target. Under normal weather conditions, the maximum distance is equal to the radar horizon or a slightly shorter distance, which is the radar range of sight.
The Rmax determined by the radar range is calculated according to the following formula.
Where: radar horizon (NM)
h1: antenna height (m)
h2: target height (m)
It should be noted that since precipitation absorbs electromagnetic waves, the actual maximum measured distance will be smaller than the result of this formula.