Rayleigh distance Rayleigh distance Rayleigh distance in optics is the axial distance from a radiating aperture to a point at which the path difference between the axial ray and an edge ray is λ / 4. An approximation of the Rayleigh Distance is formula_1, in which Z is the Rayleigh distance, D is the aperture of radiation, λ the wavelength. This approximation can be derived as follows. Consider a right angled triangle with sides adjacent formula_2, opposite formula_3and hypotenuse formula_4. According to Pythagorean theorem, formula_5. Rearranging, and simplifying formula_6 The constant termformula_7 can be neglected. In antenna applications, the Rayleigh distance is
The Wave 96.4 FM The Wave 96.4 FM 96.4 The Wave is a British Independent Local Radio station that serves the Swansea Bay area of West Wales. The station is owned by Wireless Group and mainly broadcasts chart and contemporary music, alongside news and local information, for an audience of under 40s. Initially broadcasting as 95.1 Swansea Sound on 30 September 1974, the station split into two separate services on 30 September 1995, creating a new music-led station called 96.4 Sound Wave when it moved its frequency from 95.1 FM to 96.4 FM, while Swansea Sound continued to broadcast on 1170 AM. The separate