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  2. Hallade method - Wikipedia

    en.wikipedia.org/wiki/Hallade_method

    The Hallade method, devised by Frenchman Emile Hallade, is a method used in track geometry for surveying, designing and setting out curves in railway track. [1] It involves measuring the offset of a string line from the outside of a curve at the central point of a chord. In reality, string is too thick to provide a clear reading and breaks ...

  3. Degree of curvature - Wikipedia

    en.wikipedia.org/wiki/Degree_of_curvature

    Curvature is usually measured in radius of curvature.A small circle can be easily laid out by just using radius of curvature, but degree of curvature is more convenient for calculating and laying out the curve if the radius is as large as a kilometer or mile, as is needed for large scale works like roads and railroads.

  4. Free stationing - Wikipedia

    en.wikipedia.org/wiki/Free_stationing

    In surveying, free stationing (also known as resection) is a method of determining a location of one unknown point in relation to known points. [1] There is a zero point of reference called a total station. The instrument can be freely positioned so that all survey points are at a suitable sight from the instrument.

  5. Tape correction (surveying) - Wikipedia

    en.wikipedia.org/wiki/Tape_correction_(surveying)

    In surveying, tape correction(s) refer(s) to correcting measurements for the effect of slope angle, ... is the angle between the slope line and the horizontal line, ...

  6. Tacheometry - Wikipedia

    en.wikipedia.org/wiki/Tacheometry

    Diagram of measurements: D is the slant distance; S is the horizontal distance; Δh is the vertical distance. Tacheometry ( / ˌ t æ k i ˈ ɒ m ɪ t r i / ; from Greek for "quick measure") is a system of rapid surveying , by which the horizontal and vertical positions of points on the Earth's surface relative to one another are determined ...

  7. Road curve - Wikipedia

    en.wikipedia.org/wiki/Road_curve

    Road curves are irregular bends in roads to bring a gradual change of direction. Similar curves are on railways and canals. Curves provided in the horizontal plane are known as horizontal curves and are generally circular or parabolic. Curves provided in the vertical plane are known as vertical curve.

  8. Track transition curve - Wikipedia

    en.wikipedia.org/wiki/Track_transition_curve

    The actual equation given in Rankine is that of a cubic curve, which is a polynomial curve of degree 3, at the time also known as a cubic parabola. In the UK, only from 1845, when legislation and land costs began to constrain the laying out of rail routes and tighter curves were necessary, were the principles beginning to be applied in practice.

  9. Stadiametric rangefinding - Wikipedia

    en.wikipedia.org/wiki/Stadiametric_rangefinding

    Stadiametric rangefinding is used for surveying and in the telescopic sights of firearms, artillery pieces, or tank guns, as well as some binoculars and other optics. It is still widely used in long-range military sniping , but in many professional applications it is being replaced with microwave , infrared , or laser rangefinding methods.