Topic
Parabolic reflector
About: Parabolic reflector is a research topic. Over the lifetime, 3375 publications have been published within this topic receiving 30735 citations. The topic is also known as: paraboloid reflector & paraboloidal reflector.
Papers published on a yearly basis
Papers
More filters
Patent•
17 Jul 1998
TL;DR: In this paper, a chronograph for determining the muzzle velocity of a projectile fired from either a small arm or a rifle includes two IR light beam assemblies attached to a platform with respective photodetection circuits and a clamp for holding a vertical shot dispersion monitoring target plate at a rear extremity of the platform.
Abstract: A chronograph for determining the muzzle velocity of a projectile fired from either a small arm or a rifle includes two IR light beam assemblies attached to a platform with respective photodetection circuits and a clamp for holding a vertical shot dispersion monitoring target plate at a rear extremity of the platform. The photodetection circuits provide start and stop signals for gating clock pulses of known frequency to an internal counter, the velocity being a scaled inverse of the measured interval. Each light beam assembly has two facing parabolic slit mirrors or reflectors with a photoemitter placed at one focal point and a photodetector at the other focal point for forming thin spaced beams oriented orthogonal to an intended path of the projectile. The photodetector circuit responds to a rapid drop in the total photocurrent of the photodetector in response to the partial blocking of the beam by a passing projectile. The photodetector circuit is DC coupled to the photodetector for providing an unsaturated calibration output signal. Also disclosed are design parameters for the parabolic mirrors and a method for calibrating the chronograph.
19 citations
TL;DR: A closed form expression for the wave aberration function for a plane wave reflected by a spherical mirror or a plano-corvex lens has been evaluated and compared to the results obtained from third-order aberration theory.
Abstract: Using the condition of constant optical path length for rays passing through an optical system, an equation for the wave front is presented in a simplified form. The wave front equation has been explicitly evaluated for a plane wave incident on a spherical reflector or a plano-convex lens. Then, the principal radii of curvature of the reflected or refracted wave front, evaluated directly from the wave front equation, are shown to locate the caustic surfaces of the optical system. From the wave front equation, a closed form expression for the wave aberration function for a plane wave reflected by a spherical mirror or a plano-corvex lens has been evaluated and compared to the results obtained from third-order aberration theory.
19 citations
Patent•
01 Oct 2001
TL;DR: In this paper, a system of reflectors and base of parabolic fluorescent luminary for concentrating and guiding light, with improved light output and reduction in construction cost is presented, where two of the four side walls are made of plastic, which are assembled by easy and quick snapping to the main body of iron sheet.
Abstract: System of reflectors and base of parabolic fluorescent luminary for concentrating and guiding light, with improved light output and reduction in construction cost On the support base of the electrical components of the luminary, two of the four side walls are made of plastic, which are assembled by easy and quick snapping to the main body of iron sheet These plastic side walls have specific cavities and projections for mounting a grid of parabolic reflectors, which consists of the following, two separate parts made of thin plastic film of at least one reflecting surface: (i) the main parabolic components for directing the light, which are placed under fluorescent lamps, and (ii) the upper cross-made grid, which can be removed from the luminary independently of the main parabolic components Thus, the main parabolic components do not need to have openings along the lamps As a result, their continuous parabolic shape improves significantly the light output of the parabolic luminary
19 citations
Patent•
06 Apr 1987
TL;DR: In this article, a dual frequency band microwave antenna feed for a parabolic reflector has a circular waveguide for a low frequency band and a smaller circular waveguarantee for a higher frequency band disposed in and concentric with the low band guide.
Abstract: A dual frequency band microwave antenna feed for a parabolic reflector has a circular waveguide for a low frequency band and a smaller circular waveguide for a higher frequency band disposed in and concentric with the low band guide. A twisted conductive baffle is disposed in each guide to permit 90° rotation of linearly cross-polarization signals and a pair of in-line ports is attached to each guide for output of such pairs of cross-polarization signals.
19 citations
TL;DR: In this article, a double mirror system composed of a plane and a parabolic mirror is designed to convert HPDMs into photons focused on a receiver, and an upper limit on the photon-HP kinetic mixing χ 10−8 for the mass range of 0.67-0.92 meV was obtained.
Abstract: We report on the first results from a new dish antenna search for hidden photon dark matter (HPDM) in the meV mass region. A double mirror system composed of a plane and a parabolic mirror is designed to convert HPDMs into photons focused on a receiver. In this phase 1 experiment we obtain an upper limit on the photon-HP kinetic mixing χ 10−8 for the mass range of 0.67–0.92 meV using conventional mm-wave technology with a room-temperature receiver and a small-sized mirror system.
19 citations