Lab 7 (2013) Projections

1. Download Lab07Data

File nameFile typeSize
lab07.zipZip archive data7.89 MBInfo
Projections and Geoprocessing.pdfPDF document1.76 MBInfo

2. Create a map with INDICATRIX, GRATICULE, and COUNTRIES. The CRS should be WGS84 (EPSG 4326). FYI, EPSG stands for European Petroleum Standards Group.

Move your cursor to the edges and corners of the map and determine what the global extents
(minx, miny, maxy, maxy) are. What units of measurement do these appear to be?

Characterize the indicatrix circles at the equator, at 30 degrees, and at 60 degrees.

An Azimuthal Projection

Use Save As… to create a copy of each of the layers in your map. When the dialog box comes up you will need to specify a save location and the CRS in which the layer should be saved.


Specify a CRS

Now click on Browse next to the CRS box and scroll down the zillion choices until you see Lambert Azimuthal Equal Area


Two of the variants in this section are shown below. How do you understand the relationship between the name of the CRS and what the map looks like?

EPSG3572 WGS 84 / North Pole LAEA Alaska EPSG:3575 WGS 84 / North Pole LAEA Europe
epsg3572.png epsg3575.png

FYI! In the list you'll see the acronym NSIDC EASE-Grid. This stands for National Snow and Ice Detection Center Equal Area Scaleable Earth Grid. It is especially useful for "remote sensing" data (usually this means satellite raster images).

The other one you'll notice is ETRS89. It stands for European Terrestrial Reference System 1989.
And, of course, LAEA means Lambert Azimuthal Equal Area.

Select on of the WGS LAEA coordinate reference systems for your data. Note what its EPSG number is.

Create a directory for your re-projected data

Click Browse next to the Save As box and navigate to your working directory for the lab. Create a new directory/folder called EPSGxxxx where xxxx is the EPSG number for the projection you have selected. Give the shape file the same name it had before (e.g., countries, indicatrix, or graticule).

Repeat for the other two layers so you have a complete set in the new projection.

Finish up by saving the current project as WGS_84 INTO the WGS_84 directory.

Eventually, your data will look something like this:


Check Out Your New Layers

Open new project and add the vector layers to the map. Arrange and open a print composer. Add map and legend, remove the layer items from the legend, just leaving the title. Change the title to the name of the projection, center it above the map, remove frames, increase title font size, etc. to produce something like this:


NOTE! Some re-projections will fail because something in source map can't be transformed. Antarctica often causes problems, it seems. It's OK to delete it from your countries layer and try the transformation again.

Have You Ever Been to Antarctica?

Just because you ought to see it, reproject your layers in the NSIDC EASE-Grid South EPSG:3409 projection. Label it and save.

Conical Projection

Repeat the above steps for a new projection. This time, select something under the heading of Lambert projections. Start with RGF93 Lambert 93.

When you've got your layers in the map, zoom in to the center of the map. Based on what you see there, what do you think this particular CRS is "for"?

Add the layer CACounties to this map. When you find it nowhere, select the layer in the Table of Contents, Save As… with RGF93 Lambert 93 as your CRS. Save the file into your Lambert93 folder. Add the layer to the map and remove the previous version of CACounties. Zoom in to California.


The California State Plane System - A Lambert Projection


Save the four layers into a new directory called CSSZone3 using NAD83(NSRS2007) / California zone 3 as your CRS. When this is complete, open a new project with these layers.

What to Add to Your Portfolio

  1. Azimuthal Projection Map
  2. South Pole Map
  3. Lambert Projection Map
  4. California State Plane Map

See also

File nameFile typeSize
lab07.zipZip archive data7.89 MBInfo
Projections and Geoprocessing.pdfPDF document1.76 MBInfo