Geoid and Different Height Systems

Geoid in Geodesy

• The geoid is primarily studied in geodesy as a representation of the Earth's surface, approximating the mean sea level.

Shape of the Earth

• The oblate spheroid shape is a close approximation of the geoid.

Newton's Law of Universal Gravitation

• Newton's law of universal gravitation states that every point mass attracts every other point mass by a force acting along the line intersecting both points.
• The gravitational force (F) is directly proportional to the product of the two masses (m1 and m2) and inversely proportional to the square of the distance (r) between their centers.

Particle of Mass

• In geodesy, a particle of mass m is referred to as a point mass.

Units in Geodesy

• The meter (m) is used as a unit in geodesy.

Role of the Geoid

• The primary role of the geoid in geodesy is to provide a reference surface for measuring heights and gravity field observations.

Reference Ellipsoid

• The reference ellipsoid plays a role in geodesy as a mathematically defined surface, providing a close approximation of the geoid, but smoother and more regular in shape.

Significance of the Geoid

• The main significance of the Earth's geoid in geodesy is that it represents the equipotential surface of the Earth's gravity field.

Geoid vs. Reference Ellipsoid

• The geoid differs from a reference ellipsoid in geodesy as it is a more accurate representation of the Earth's surface, while the reference ellipsoid is a simplified model.

Test your knowledge of the geoid and different height systems with this quiz. Explore the concepts of geodesy, reference ellipsoid, normal ellipsoid, and the shape of the Earth.