How Were Geodetic Datums Established?

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  • Опубліковано 1 гру 2024

КОМЕНТАРІ • 12

  • @jdtaramona1
    @jdtaramona1 10 років тому

    Very goog video for begineers. I am very excited about more advanced topics related to Geodesy.

  • @mitchelhanlon6989
    @mitchelhanlon6989 9 років тому +1

    Good image of the survey for the Sydney Harbour Bridge

  • @theplanetruth
    @theplanetruth 2 роки тому +1

    When surveying a distance between two points, how does one differentiate between elevation change and earth curve?

    • @davidstirling7992
      @davidstirling7992 Рік тому +2

      Clearly they don’t or didn’t. Suddenly all the globe earthers are throwing this geodacy at me. As far as I can tell it’s all triangulation at the ground level, not till it gets to the actual map makers does any of the curve maths seem to enter any of the equations!

    • @dennispickard7743
      @dennispickard7743 Рік тому +1

      @@davidstirling7992 yup ! Well said . Globtardia are forgetting two major factors -
      (1) allegedly our is supposed to be an oblate spheroid and not a globe ( they are neither )
      (2) our earth has topography ranging from vast mountain ranges to very deep canyons,globlings believe it’s like a cue ball ??
      A theodolite is used for comparing elevations , but firstly it is calibrated by a simple bubble spirit level - if the datum is level , then you have an unwavering reference point .

    • @TheDMG45
      @TheDMG45 Рік тому

      You don't. Heights are measured separately by comparing differences in acceleration due to gravity, which is constant at mean sea level. Measurement of heights relative to other points is accurate only within a local area.

  • @DCARA06
    @DCARA06 9 років тому +2

    Thank you, this was very informative!

  • @pauladams5083
    @pauladams5083 3 роки тому +4

    Plane surveying is the process of surveying by assuming that the earth is flat. Which means the curvature or spherical shape of the earth is not considered in plane surveying calculations. Geodetic surveying is a process of surveying by considering the curvature or spherical shape of the earth.
    FYI -- plane surveyors and geodetic surveyors work from the same benchmarks.
    It's flat folks.

    • @unarammer2003
      @unarammer2003 3 роки тому +2

      flat and stationary...proven!!
      the globe is ridiculous

    • @TheDMG45
      @TheDMG45 Рік тому

      Geodetic surveyors don't work from the benchmarks, they establish where the benchmarks are in the first place.

  • @unarammer2003
    @unarammer2003 3 роки тому +2

    good thing the earth is flat...

  • @turbodub501
    @turbodub501 7 років тому +4

    flat