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Historically, roof pitch was designated in two other ways: A ratio of the ridge height to the width of the building (span) [6] and as a ratio of the rafter length to the width of the building. [7] Commonly used roof pitches were given names such as: Greek: the ridge height is 1 ⁄ 9 to 1 ⁄ 7 the span (an angle of 12.5° to 16°);
The 90-degree complement to the angle of incidence is called the grazing angle or glancing angle. Incidence at small grazing angles is called "grazing incidence." [citation needed] Grazing incidence diffraction is used in X-ray spectroscopy and atom optics, where significant reflection can be achieved only at small values of the grazing angle.
This angle γ = 90° − β is called grazing angle. The angle θ = ε + 90° is used for a mathematical description in a spherical coordinate system. For the approximation of a flat earth – which is usual for airborne radar with short to medium range – the grazing angle and the depression angle can be assumed to be equal γ = ε and the ...
Bonnet roof: A reversed gambrel or Mansard roof with the lower portion at a lower pitch than the upper portion. Monitor roof: A roof with a monitor; 'a raised structure running part or all of the way along the ridge of a double-pitched roof, with its own roof running parallel with the main roof.'
The surface clutter return depends upon the nature of the surface, its roughness, the grazing angle (angle the beam makes with the surface), the frequency and the polarisation. The reflected signal is the phasor sum of a large number of individual returns from a variety of sources, some of them capable of movement (leaves, rain drops, ripples ...
The angle of incidence, α, is close to the critical angle for the sample. The beam is diffracted in the plane of the surface of the sample by the angle 2θ, and often also out of the plane. Grazing incidence diffraction ( GID ) is a technique for interrogating a material using small incidence angles for an incoming wave, often leading to the ...
The Littrow configuration is a special geometry in which the blaze angle is chosen such that diffraction angle and incidence angle are identical. [1] For a reflection grating, this means that the diffracted beam is back-reflected into the direction of the incident beam (blue beam in picture). The beams are perpendicular to the step and ...
Grazing-incidence small-angle scattering (GISAS) is a scattering technique used to study nanostructured surfaces and thin films. The scattered probe is either photons ( grazing-incidence small-angle X-ray scattering , GISAXS ) or neutrons ( grazing-incidence small-angle neutron scattering , GISANS ).