Spatial referencing
An overview
Richard Knippers
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Guidelines and tips
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Spatial Referencing: Understanding Map Projections, Coordinate Systems, and Datums, Lecture notes of Literature
An overview of spatial referencing, focusing on the relevance and use of reference surfaces, coordinate systems, and coordinate transformations in mapping. It covers the concepts of geoids, ellipsoids, datums, map projections, and coordinate systems, as well as the principles of transforming maps from one projection system to another. The document also discusses trends in mapping and the importance of global vertical and horizontal datums.
Typology: Lecture notes
2021/2022
1 / 61
This page cannot be seen from the preview
Don't miss anything!
Related documents
Partial preview of the text
Download Spatial Referencing: Understanding Map Projections, Coordinate Systems, and Datums and more Lecture notes Literature in PDF only on Docsity!
Spatial referencing
An overview^ Richard Knippers
Learning instructions
Learning activities:
Literature: ITC Core textbook, Chapter 3.1 onSpatial Referencing. Website: http://kartoweb.itc.nl/geometrics Exercise: Spatial referencing (ArcMap10)
Questions:
Blackboard Discussion Board
Contents
Spatial reference surfaces and datums
The Geoid – vertical (height) datum The Ellipsoid – horizontal (geodetic) datum Local and global datums
Map projections
Classification of map projections Map projection selection Map coordinate systems (e.g. UTM)
Coordinate transformations
Cone Plane Ellipsoid (best fitting) Geodetic (or horizontal) datum The Earth: a complex shape Mapping surface Independent handling of horizontal and vertical Cylinder Earth to Map
Spatial reference surface
The Geoid
The Geoid – Vertical (height) datum
The Earth The Geoid Global Sea Level
Vertical datums
Every country (or group of countries) has it’s own Mean Sea Level - its own vertical (height) datum. The Netherlands Belgium MSL of Belgium is 2.34m lower than MSL of The Netherlands
At what height do we live? http://www.ahn.nl/postcodetool
Elevation data are related to Amsterdam Zero (N.A.P.)
Ellipsoidal height Orthometric height (height above the Geoid)
Ellipsoidal height versus Orthometric height
Relation between Geoid and Ellipsoid^ The earth’s surface, and the geoid and a reference ellipsoid used to
approximate it. The geoidal undulation (N) is the separation between the geoid and an ellipsoid. It varies globally between ± 110 m. H^ N h N H = Orthometric heighth = Ellipsoidal heightN = Geoidal separation (undulation)
Spatial reference surface
The Ellipsoid
The Ellipsoid
Typical values of the parameters for an ellipsoid: a = 6378137.0 m b = 6356752.31 m f = 1/298. e = 0. Flattening: Eccentricity: f = (a-b)/a e 2 = (a 2
- b 2 )/a 2
Local and global ellipsoids/datums
The ellipsoid is chosen in such way that it best fits the surface of the area of interest (the country) e.g. WGS e.g. Amersfoort (Bessel)
Local datum system of the Netherlands
Ellipsoid Bessel ellipsoid Amersfoort datum National triangulation network φ = 52A ° 13' 26.2"N λ = 06A ° 53' 32.1"E X RD = 257776.47m Y RD = 471588.14m Geodetic datum φ = 52A ° 9' 22.2“ λ = 5A ° 23' 15.5" X RD = 155 000m Y RD = 463 000m