Geometric Geodesy

Question 1

Earth as an ellipsoid.

Question 2

• Obtained by rotating an ellipse about its minor axis
• Coincides with Earth’s spin axis
• Best geometric representation of the geoid
• Datum for horizontal position

Answer 2

Ellipsoid

Question 3

Plane that cut the surface of the ellipsoid forming a curve

Answer 3

Normal sections

Question 4

Principal normal section

Answer 4

1. Meridional section
2. Prime vertical section

Question 5

• Plane passing through given point and the two points.
• Since ø are different = radius will be different
• At Cutting Poles = Azimuth is 0 or 180°

Answer 5

Meridional section

Question 6

• Perpendicular to the poles
• Point and perpendicular to the meridional section at the point.
• Also denotes the Radius of Curvature (N)
  Prime Vertical Section = Azimuth is 90° or 270 °

Answer 6

Prime vertical section

Question 7

Integral mean radius of the Earth on a point taken over the azimuth varying from 0°- 360°

Answer 7

Gaussian mean radius

Question 8

Radius of the Parallel

Answer 8

Prime vertical radius

Question 9

Radius of a sphere with same volume of an ellipsoid

Answer 9

Spherical approximation of the ellipsoid

Question 10

Computation of X,Y, Z coordinates of a point located at a geometric height.

Answer 10

Formula:
X= (N+h)cos⁡ ∅cos⁡𝜆
Y= (N+h)cos⁡ ∅sin⁡𝜆
Z= (N (1-𝒆^𝟐)+h) sin⁡𝝓