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  2. Four prism dioptre reflex test - Wikipedia

    en.wikipedia.org/wiki/Four_prism_dioptre_reflex_test

    The Four Prism Dioptre Reflex Test (also known as the 4 PRT, or 4 Prism Dioptre Base-out Test) is an objective, non-dissociative test used to prove the alignment of both eyes (i.e. the presence of binocular single vision) by assessing motor fusion. [1] Through the use of a 4 dioptre base out prism, diplopia is induced which is the driving force ...

  3. CUSUM - Wikipedia

    en.wikipedia.org/wiki/CUSUM

    The target value, T, of the quality characteristic. Upper control limit. Lower control limit. Plotted statistic. In statistical quality control, the CUSUM (or cumulative sum control chart) is a sequential analysis technique developed by E. S. Page of the University of Cambridge. It is typically used for monitoring change detection. [1]

  4. Klinkenberg correction - Wikipedia

    en.wikipedia.org/wiki/Klinkenberg_correction

    Klinkenberg correction. In Petrophysics a Klinkenberg correction is a procedure for calibration of permeability data obtained from a minipermeameter device. A more accurate correction factor can be obtained using Knudsen correction. When using nitrogen gas for core plug measurements, the Klinkenberg correction is usually necessary due to the so ...

  5. Snellen chart - Wikipedia

    en.wikipedia.org/wiki/Snellen_chart

    Snellen chart is used to estimate visual acuity (last three rows are 20/15, 20/13 and 20/10) A Snellen chart is an eye chart that can be used to measure visual acuity. Snellen charts are named after the Dutch ophthalmologist Herman Snellen who developed the chart in 1862 as a measurement tool for the acuity formula developed by his professor ...

  6. Maddox rod - Wikipedia

    en.wikipedia.org/wiki/Maddox_rod

    The strength of the prism is increased until the streak of the light passes through the centre of the prism, as the strength of the prism indicates the amount of deviation present. The Maddox rod is a handheld instrument composed of red parallel plano convex cylinder lens , which refracts light rays so that a point source of light is seen as a ...

  7. Abbe–Koenig prism - Wikipedia

    en.wikipedia.org/wiki/Abbe–Koenig_prism

    An Abbe–Koenig prism is a type of reflecting prism, used to invert an image (rotate it by 180°). They are commonly used in binoculars and some telescopes for this purpose. The prism is named after Ernst Abbe and Albert Koenig . The prism is made from two glass prisms, which are optically cemented together to form a symmetric, shallow Vee ...

  8. Sheppard's correction - Wikipedia

    en.wikipedia.org/wiki/Sheppard's_correction

    Sheppard's correction. In statistics, Sheppard's corrections are approximate corrections to estimates of moments computed from binned data. The concept is named after William Fleetwood Sheppard . Let be the measured kth moment, the corresponding corrected moment, and the breadth of the class interval (i.e., the bin width).

  9. Atmospheric correction - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_correction

    Atmospheric correction is the process of removing the scattering and absorption effects of the atmosphere on the reflectance values of images taken by satellite or airborne sensors. [1] [2] Atmospheric effects in optical remote sensing are significant and complex, dramatically altering the spectral nature of the radiation reaching the remote ...