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  2. Dead reckoning - Wikipedia

    en.wikipedia.org/wiki/Dead_reckoning

    Dead reckoning. The navigator plots their 9 a.m. position, indicated by the triangle, and, using their course and speed, estimates their own position at 9:30 and 10 a.m. In navigation, dead reckoning is the process of calculating the current position of a moving object by using a previously determined position, or fix, and incorporating ...

  3. Comoving and proper distances - Wikipedia

    en.wikipedia.org/wiki/Comoving_and_proper_distances

    The comoving distance from an observer to a distant object (e.g. galaxy) can be computed by the following formula (derived using the Friedmann–Lemaître–Robertson–Walker metric): = ′ (′) where a(t′) is the scale factor, t e is the time of emission of the photons detected by the observer, t is the present time, and c is the speed of ...

  4. Set and drift - Wikipedia

    en.wikipedia.org/wiki/Set_and_drift

    A Dead Reckoning, DR, is calculated by using a previously determined position on a chart, and advancing that position based on known or estimated speed over a set amount of time. This can be calculated by using the formula Speed = Distance ÷ Time. [3] Once an advance position has been plotted, then set and drift can be factored in.

  5. Naismith's rule - Wikipedia

    en.wikipedia.org/wiki/Naismith's_rule

    Assuming an individual can maintain a speed on the flat of 5 km/h, the route will take 6 hours and 34 minutes. The simplicity of this approach is that the time taken can be easily adjusted for an individual's own (chosen) speed on the flat; at 8 km/h (flat speed) the route will take 4 hours and 6 minutes.

  6. Triangulation - Wikipedia

    en.wikipedia.org/wiki/Triangulation

    Measuring the height of a building with an inclinometer. Triangulation today is used for many purposes, including surveying, navigation, metrology, astrometry, binocular vision, model rocketry and, in the military, the gun direction, the trajectory and distribution of fire power of weapons. The use of triangles to estimate distances dates to ...

  7. Light-year - Wikipedia

    en.wikipedia.org/wiki/Light-year

    The product of Simon Newcomb's J1900.0 mean tropical year of 31 556 925.9747 ephemeris seconds and a speed of light of 299 792.5 km/s produced a light-year of 9.460 530 × 10 15 m (rounded to the seven significant digits in the speed of light) found in several modern sources [10] [11] [12] was probably derived from an old source such as C. W ...

  8. Haversine formula - Wikipedia

    en.wikipedia.org/wiki/Haversine_formula

    Δ λ = λ 2 − λ 1 {\displaystyle \Delta \lambda =\lambda _ {2}-\lambda _ {1}} . Finally, the haversine function hav (θ), applied above to both the central angle θ and the differences in latitude and longitude, is. The haversine function computes half a versine of the angle θ, or the squares of half chord of the angle on a unit circle ...

  9. Equations of motion - Wikipedia

    en.wikipedia.org/wiki/Equations_of_motion

    To state this formally, in general an equation of motion M is a function of the position r of the object, its velocity (the first time derivative of r, v = ⁠dr dt⁠), and its acceleration (the second derivative of r, a = ⁠d2r dt2⁠), and time t. Euclidean vectors in 3D are denoted throughout in bold.