Experimental determination of diffraction losses where there is a slight lack of clearance in the first Fresnel zone in the 15 GHz range

Diffraction losses are measured with a slight lack of clearance in the first Fresnel zone for the case of a smooth spherical earth in a range between freespace transmission and grazing incidence by equal field lengths and equal antenna heights using tides at a height of 3.6 m in the Jadebusen at the North Sea. Tides in Wilhelmshaven in the southern part of the North Sea are examined, and the tidal curve, which lasts 12.5 hours, is presented. A projecting curve for the diffraction loss for a frequency range of 15 GHz is derived.