OpenGIS Workshop

1. Overview Raster in QGIS NetCDF Working with NetCDF
OpenGIS Workshop. Gridded data
Giorgio Santinelli
November 3, 2014

2. Overview Raster in QGIS NetCDF Working with NetCDF
Index
1 Overview
Definition
Grids
2 Raster in QGIS
WMS
gdal
3 NetCDF
NetCDF Definition
CF conventions
4 Working with NetCDF
NetCDF generation
Tutorials

3. Overview Raster in QGIS NetCDF Working with NetCDF
Definition
Multidimensional rectangular array of grid points containing
values?

4. Overview Raster in QGIS NetCDF Working with NetCDF
Features of gridded data
Features
Format
Dimensionality
Spacing
Number and type of values stores

5. Overview Raster in QGIS NetCDF Working with NetCDF
Applications
Data world
Data exploration
Data dissemination

6. Overview Raster in QGIS NetCDF Working with NetCDF
Applications
Data world
Data exploration
Data dissemination
Models
Numerical modelling...
Meteorology/Oceanography/Climate
Finite volume/difference methods

7. Overview Raster in QGIS NetCDF Working with NetCDF
Data grids

8. Overview Raster in QGIS NetCDF Working with NetCDF
Data grids
Dataset type?
Main variables?
Number of dimensions?

9. Overview Raster in QGIS NetCDF Working with NetCDF
Data grids
Dataset type?
Main variables?
Number of dimensions?
Showing concentration plots for given time and space
Showing inflows from rivers of nutrients a user defined
stretches / patches
Calculate spatially distributed data products

10. Overview Raster in QGIS NetCDF Working with NetCDF
Grids (math)
A grid usually refers to two or more infinite sets of evenly-spaced
parallel lines at particular angles to each other in a plane, or the
intersections of such lines.

11. Overview Raster in QGIS NetCDF Working with NetCDF
Grids (math)
A grid usually refers to two or more infinite sets of evenly-spaced
parallel lines at particular angles to each other in a plane, or the
intersections of such lines.

12. Overview Raster in QGIS NetCDF Working with NetCDF
Regular grids
Tessellation of regular polygons

13. Overview Raster in QGIS NetCDF Working with NetCDF
Regular grids
Tessellation of regular polygons

14. Overview Raster in QGIS NetCDF Working with NetCDF
Rectilinear grids
Congruent Tessellation.
Uniform?

15. Overview Raster in QGIS NetCDF Working with NetCDF
Rectilinear grids
Congruent Tessellation.
Uniform?

16. Overview Raster in QGIS NetCDF Working with NetCDF
Rectilinear grids
Congruent Tessellation. Curvilinear grids

17. Overview Raster in QGIS NetCDF Working with NetCDF
Delft3d grids
Congruent Tessellation.

18. Overview Raster in QGIS NetCDF Working with NetCDF
Delft3d grids
Congruent Tessellation.
Delft3D

19. Overview Raster in QGIS NetCDF Working with NetCDF
Unstructured grids
Irregular tessellation of simple shapes

20. Overview Raster in QGIS NetCDF Working with NetCDF
Unstructured grids
Irregular tessellation of simple shapes
Similarity with graph data structure

21. Overview Raster in QGIS NetCDF Working with NetCDF
Unstructured grids: FEWS

22. Overview Raster in QGIS NetCDF Working with NetCDF
Unstructured grids: D-Flow FM

23. Overview Raster in QGIS NetCDF Working with NetCDF
Unstructured grids: D-Flow FM

24. Overview Raster in QGIS NetCDF Working with NetCDF
Unstructured grids: D-Flow FM
...FM stands for flexible mesh

25. Overview Raster in QGIS NetCDF Working with NetCDF
Working with Raster

26. Overview Raster in QGIS NetCDF Working with NetCDF
WMS
openlayers WMS
NOAA WMS

27. Overview Raster in QGIS NetCDF Working with NetCDF
gdal library
gdal
Gdal is a translator library for raster and vector geospatial data
formats
Features

28. Overview Raster in QGIS NetCDF Working with NetCDF
gdal library
gdal
Gdal is a translator library for raster and vector geospatial data
formats
Features Raster utility programs:
gdalinfo, gdal translate, gdaladdo, gdalwarp, ...
Vector utility programs:
ogrinfo, ogr2ogr, ogrtindex, ...
gdal webpage
QGIS uses it in the back-end.

29. Overview Raster in QGIS NetCDF Working with NetCDF
gdal in other languages
Shell (cross-platform)

30. Overview Raster in QGIS NetCDF Working with NetCDF
gdal in other languages
Shell (cross-platform)
Bindings:
C++
Python osgeo
R rgdal
Matlab MEXGDAL
...

31. Overview Raster in QGIS NetCDF Working with NetCDF
Working with NetCDF

32. Overview Raster in QGIS NetCDF Working with NetCDF
Working with NetCDF
File Format

33. Overview Raster in QGIS NetCDF Working with NetCDF
Working with NetCDF
File Format
Library

34. Overview Raster in QGIS NetCDF Working with NetCDF
Working with NetCDF
File Format
Library
Interface

35. Overview Raster in QGIS NetCDF Working with NetCDF
Working with NetCDF
File Format
Library
Interface
General information on NetCDF are available.

36. Overview Raster in QGIS NetCDF Working with NetCDF
Working with NetCDF
Openearth.eu

37. Overview Raster in QGIS NetCDF Working with NetCDF
CF Conventions
NetCDF Climate and Forecast Metadata Conventions
cfconventions

38. Overview Raster in QGIS NetCDF Working with NetCDF
OET & NetCDF
Links in OET:
Python:
OET python nc, OET python tutorial
Matlab:
OET matlab nc, OET matlab tutorial

39. Overview Raster in QGIS NetCDF Working with NetCDF
Opendap
It strongly depends on the language. Many tutorials are available
on line. Creating netCDF files that are fully self-descriptive and
comply with the CF convention is not trivial

40. Overview Raster in QGIS NetCDF Working with NetCDF
Opendap
It strongly depends on the language. Many tutorials are available
on line. Creating netCDF files that are fully self-descriptive and
comply with the CF convention is not trivial
As a start you could use OET netcdfkickstarter.
kickstarter wiki page
netcdfkickstarter

41. Overview Raster in QGIS NetCDF Working with NetCDF
Opendap
Browse
Deltares OPeNDAP server http://opendap.deltares.nl/
List of OPeNDAP servers worldwide (remote servers)

42. Overview Raster in QGIS NetCDF Working with NetCDF
Opendap
Browse
Deltares OPeNDAP server http://opendap.deltares.nl/
List of OPeNDAP servers worldwide (remote servers)
opendap.deltares.nl

43. Overview Raster in QGIS NetCDF Working with NetCDF
Tutorials
OET OpenGIS
bit.ly/gisworkshop