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Coordinate Systems and South African Coordinate Systems
- 1.
- 2. Agenda • What AreThey? • Geographic Coordinate Systems • Projected Coordinate Systems • South African Coordinate Reference System • Demonstration
- 3. Coordinate Systems –What are they? • Method to ID location of a point on Earth. • Coordinates?? What do they indicate? • Some mathematics involved • Basic Elements – Choice of…… • Origin (0,0) – Reference point - Central Meridian?? • Axes (X,Y) – What do X & Y indicate?? • Positive direction for each axis • Unit vectors at every point in space
- 4. Coordinate Systems cont. •Spherical Coordinate Systems • Latitude • Longitude • Cylindrical Coordinate Systems • Cartesian Coordinate Systems • Planar – 2D • Metres
- 5. Agenda • What AreThey? • Geographic Coordinate Systems • Projected Coordinate Systems • South African Coordinate Reference System • Demonstration
- 6. Geographic Coordinate Systems •Datum? • Ellipsoid? • Geoid?
- 7. Projected Coordinate Systems •Map Projections - mathematical equations used to transform latitude and longitude coordinates to plane coordinates • Transverse Mercator? • Central Meridian • Latitude of Projection Origin • Scale Factor at Central Meridian • Standard Lines
- 8. South African CoordinateSystems • Cape Datum 1880 • Hartebeeshoek 1994 • WGS 1984 • Transverse Mercator
- 9. Transformations • Transform fromone projection to the other • Cape to Haartebeeshoek, vice versa • Hartebeeshoek to WGS, vice versa • Difference?
- 10. Demonstration • Recognising Coordinates •Are we in the right place? How do we know?
- 11. • https://www.caliper.com/glossary/what-is-a-coordinate-system.htm • http://gis.humboldt.edu/OLM/Lessons/GIS/03%20Projections/Introd uctionToCoordinateSystems1.html •https://mgimond.github.io/Spatial/chp09_0.html • https://gisgeography.com/central-meridian/ • https://www.e-education.psu.edu/natureofgeoinfo/c2.html
Editor's Notes
- #3 a method for identifying the location of a point on the earth. Most coordinate systems use two numbers, a coordinate, to identify the location of a point. Each of these numbers indicates the distance between the point and some fixed reference point, called the origin. The first number, known as the X value, indicates how far left or right the point is from the origin. The second number, known as the Y value, indicates how far above or below the point is from the origin. The origin has a coordinate of 0, 0.