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 Crests was born and where he began his music career, introduced an Extension of Remarks in the House of Representatives. This posthumous honor is now a permanent part of the Congressional Record. The Extension of Remarks includes the original members of The Crests. On November 12, 2013, J.T. Carter was honored by the Pennsylvania State House, Speaker of the House Sam Smith, and PA State Representative Rosemary M Brown, for his lifetime in the music industry and for being the first African American to form an interracial vocal group in the America. Carter was officially recognized on the state house floor.