Category : Topography notes

There are three way to model the Earth’s shape: Plane (“Topographical plane”) Sphere (“Local Sphere”) Ellipsoid Geoid Plane Earth’s shape approximation: Topographical plane For very small earth’s shape modeling we can use a simple plan to represent it. The figure above illustrate the condition of two point A and B; the distance between A and ..

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Diagram of relative azimuth

How to transform cartesian coordinates into polar coordinate, relate to a segment, also called Azimuth. Etymology (by Wikipedia) The word azimuth is in all European languages today. It originates from medieval Arabic al-sumūt, pronounced as-sumūt in Arabic, meaning “the directions” (plural of Arabic al-samt = “the direction”). Consider the figure In this post we talk ..

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Coordinates rotation. If we indicate with the angle of rotation between the origin cartesian system to the new cartesian system, and if we indicate with the polar coordinates of point P in origin system, we can determine these relations (look the figure): There is another (but most used) kind of way to change the coordinates: ..

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  We consider a new origin of new two axes, called O’. Consider the cartesian coordinate of O’ in actual cartesian system. We have: We suppose that the new cartesian system is no rotated, and the new axes is parallels to the actuals. The coordinates of a point (called P) are: Topography notes: Table o..

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For determine all parameters of a quadrilateral is necessary to know five elements, two of those must be sides. The quadrilateral can be subdivided in many way: Two triangles Subtraction of two triangles One rectangle and three right triangles Topography notes: Table o..

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Circumscribed circle (circumcircle) of a triangle The center of a circumcircle of a triangle is given by interception of the axes of sides. We have: If we don’t know any angles of the triangle we can use this: Incircle, inscribed circle The center of the inscribed ciricle of a triangle is also called incenter. The ..

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To solve a scalene triangle we need three element: one of wich must be a side. Now we explain all cases. Case a) knowing one side and adjacent angles of a triangle: To solve and determine all other paramether of the triangle we follow these steps: We know: , we looking for The sum of ..

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