Difference between revisions of "QGIS/C2/Coordinate-Reference-Systems/English"

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(Created page with "{|border=1 ||'''Visual Cue''' ||'''Narration''' |- || '''Slide Number 1''' '''Title Slide''' || Welcome to this tutorial on '''Coordinate Reference System '''in''' QGIS'''....")
 
Line 14: Line 14:
 
|| In this tutorial, we will learn to,
 
|| In this tutorial, we will learn to,
  
−
Add layers to '''projections''' in '''QGIS'''.
+
*Add layers to '''projections''' in '''QGIS'''.
  
−
View '''metadata''' information for layers.
+
*View '''metadata''' information for '''layers'''.
  
−
Save selected features from a '''layer''' to a new '''layer'''.
+
*Save selected features from a '''layer''' to a new '''layer'''.
−
 
+
−
Re-project and overlay '''data layers''' of different '''projections''' together.
+
  
 +
*Re-project and overlay '''data layers''' of different '''projections''' together.
  
 
|-
 
|-
Line 29: Line 28:
 
|| To record this tutorial I am using,
 
|| To record this tutorial I am using,
  
−
'''Ubuntu Linux OS '''version''' '''16.04  
+
*'''Ubuntu Linux OS '''version''' '''16.04  
  
−
'''QGIS''' version 2.18
+
*'''QGIS''' version 2.18
  
 
|-
 
|-
Line 38: Line 37:
 
'''Pre-requisites'''
 
'''Pre-requisites'''
  
−
 
+
*'''Basic knowledge about GIS.'''
−
'''Basic knowledge about GIS.'''
+
*Please view pre-requisite tutorial in this series.
−
 
+
−
 
+
−
'''Please view pre-requisite tutorial in this series.'''
+
−
 
+
−
 
+
−
'''Link: https://spoken-tutorial.org/tutorial-search/?search_foss=QGIS&search_language=English'''
+
 
|| To follow this tutorial you should have basic knowledge about '''GIS.'''
 
|| To follow this tutorial you should have basic knowledge about '''GIS.'''
  
  
 
Please view previous tutorial in this series.
 
Please view previous tutorial in this series.
−
 
−
 
−
 
  
 
|-
 
|-
Line 61: Line 51:
  
  
−
Coordinate Reference Systems are of two types,
+
'''Coordinate Reference Systems''' are of two types,
−
 
+
−
 
+
−
'''Geographic coordinate system'''
+
−
 
+
−
 
+
−
'''Projected Coordinate System'''
+
−
 
+
−
 
+
  
 +
*'''Geographic coordinate system'''
 +
*'''Projected Coordinate System'''
  
 
|-
 
|-
Line 76: Line 60:
  
 
'''Coordinate Reference systems'''
 
'''Coordinate Reference systems'''
−
||Most widely used geographic coordinate system is '''WGS 84.'''
+
||Most widely used '''geographic coordinate system''' is '''WGS 84.'''
−
 
+
−
Most widely used projected coordinate system is '''UTM''' (Universal Transverse Mercator).
+
−
 
+
  
 +
Most widely used '''projected coordinate system''' is '''UTM'''.
  
 
|-
 
|-
Line 90: Line 72:
  
  
−
On the canvas world map with country administration boundaries is displayed.
+
On the '''canvas''', world map with country administration boundaries is displayed.
  
 
|-
 
|-
Line 96: Line 78:
  
 
'''World Map File'''
 
'''World Map File'''
−
|| Demonstration on how to download the map,
+
|| Demonstration on how to download the map and display in '''QGIS''' is explained in the prerequisite tutorial.
−
 
+
−
 
+
−
and display in QGIS is explained in the prerequisite tutorial.
+
  
  
Line 105: Line 84:
  
  
−
This file can also be downloaded from the code files link.
+
This file can also be downloaded from the '''Code files''' link.
  
 
|-
 
|-
 
|| Cursor on '''layers panel on '''name of the map file.
 
|| Cursor on '''layers panel on '''name of the map file.
−
|| On the left-side of the canvas,you will see '''Layers Panel''',
+
|| On the left-side of the '''canvas''', you will see '''Layers Panel''', with file name of the world map as a '''layer'''.
−
 
+
−
with file name of the world map as a layer.
+
−
 
+
  
 
|-
 
|-
Line 135: Line 111:
  
 
From the sub-menu, click on '''Layer Panel'''.
 
From the sub-menu, click on '''Layer Panel'''.
−
|| Sub-menu shows a list of panel names.
+
|| Sub-menu shows a list of '''panel''' names.
  
  
−
Click on '''Layer Panel''' option to enable or disable the panel.  
+
Click on '''Layer Panel''' option to enable or disable the '''panel'''.  
  
 
|-
 
|-
 
|| Drag the boundary with the mouse.
 
|| Drag the boundary with the mouse.
−
|| We can adjust the size of the panel by dragging the boundary.
+
|| We can adjust the size of the '''panel''' by dragging the boundary.
  
 
|-
 
|-
Line 148: Line 124:
  
  
−
 
+
|| If you wish to change the color of the map, right-click on the '''layer''' name in the '''Layers Panel.'''
−
|| If you wish to change the color of the map,
+
−
 
+
−
 
+
−
Right-click on the layer name in the '''Layers Panel.'''
+
  
 
|-
 
|-
 
|| Scroll-down the '''context menu''' and select '''Styles''' option.
 
|| Scroll-down the '''context menu''' and select '''Styles''' option.
−
 
−
 
−
Rotate the vertex of the color triangle to choose the color.
 
 
|| Scroll-down the '''context menu''' and select '''Styles''' option.
 
|| Scroll-down the '''context menu''' and select '''Styles''' option.
 +
 +
|-
 +
||Rotate the vertex of the color triangle to choose the color.
  
  
−
Sub-menu shows a color triangle .
+
||Sub-menu shows a color triangle .
  
  
Line 169: Line 141:
 
|-
 
|-
 
|| Click anywhere on the canvas.
 
|| Click anywhere on the canvas.
−
|| Click anywhere on the canvas to close the context menu.
+
|| Click anywhere on the '''canvas''' to close the context menu.
  
 
|-
 
|-
Line 176: Line 148:
  
  
−
|| At the bottom-left corner, on the status bar, of '''QGIS''' window,  
+
|| At the bottom-left corner, on the '''status''' bar of '''QGIS''' window, you will notice  
−
 
+
*the label '''Coordinate '''
−
 
+
*and a text box with numbers.
−
you will notice the label '''Coordinate '''and a text box with numbers.
+
  
 
|-
 
|-
 
|| Highlight X and Y coordinates. (Editing stage)
 
|| Highlight X and Y coordinates. (Editing stage)
−
|| Values of '''X ''' and '''Y''' coordinates for a particular location are shown in this text box.  
+
|| Values of '''X ''' and '''Y coordinates''' for a particular location are shown in this text box.  
  
 
|-
 
|-
Line 193: Line 164:
  
  
−
Observe, that the values of X and Y coordinates change with the location of the cursor.
+
Observe, that the values of '''X''' and '''Y coordinates''' change with the location of the cursor.
  
 
|-
 
|-
Line 204: Line 175:
 
|-
 
|-
 
|| Point towards '''EPSG:4326(OTF) '''on the bottom-right corner of the status bar.
 
|| Point towards '''EPSG:4326(OTF) '''on the bottom-right corner of the status bar.
−
|| On the '''status bar''', at the bottom-right corner,
+
|| On the '''status bar''', at the bottom-right corner, you will see another '''label, Current CRS.'''
−
 
+
−
 
+
−
you will see another label, '''Current CRS.'''
+
  
  
Line 218: Line 186:
 
|-
 
|-
 
|| Right click on the Layers Panel, '''ne_10m_admin_0_countries'''
 
|| Right click on the Layers Panel, '''ne_10m_admin_0_countries'''
−
 
+
|| On the '''Layers Panel''', right-click on the '''layer''' name.
−
 
+
−
 
+
−
|| On the '''Layers Panel''',
+
−
 
+
−
 
+
−
right-click on the layer name.
+
  
 
|-
 
|-
 
|| From the context menu, select '''Properties'''.
 
|| From the context menu, select '''Properties'''.
−
 
  
  
Line 237: Line 198:
  
 
|-
 
|-
−
|| Click on '''Metadata''' option in Layer dialog-box.
+
|| Click on '''Metadata''' option in '''Layer''' dialog-box.
  
  
−
Click on Back arrow next to properties.
+
Click on back arrow next to properties.
  
 
Scroll down.
 
Scroll down.
Line 247: Line 208:
  
 
Under '''Properties '''section, scroll down the slider.
 
Under '''Properties '''section, scroll down the slider.
−
 
−
 
−
 
  
 
|-
 
|-
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|| At the bottom,  
 
|| At the bottom,  
  
−
 
+
*under heading, '''Layer Spatial Reference System,'''
−
Under heading, '''Layer Spatial Reference System,'''
+
*you will see the definition for this projection.
−
 
+
−
 
+
−
you will see the definition for this projection.
+
  
  
Line 272: Line 227:
 
|-
 
|-
 
|| Click '''Ok''' button
 
|| Click '''Ok''' button
−
|| Click on '''Ok''' button, to close the dialog box.
+
|| Click on '''Ok''' button at the bottom, to close the dialog box.
  
 
|-
 
|-
 
||  
 
||  
−
|| Let us now add layers to the map and change the '''projection'''.
+
|| Let us now add '''layers''' to the map and change the '''projection'''.
  
 
|-
 
|-
Line 284: Line 239:
 
|| About '''data layers'''.
 
|| About '''data layers'''.
  
−
 
+
*Usually '''geographical data''' is stored in '''layers''' in a '''GIS''' workspace.
−
 
+
−
Usually geographical data is stored in layers in a '''GIS''' workspace.<br/>
+
*Each '''layer''' has '''data''' stored in its '''attribute table'''.
−
 
+
−
Each layer has data stored in its '''attribute table'''.<br/>
+
*Many '''layers''' can represent '''data''' of the same geographical location.
−
 
+
−
Many layers can represent data of the same geographical location.
+
−
 
+
−
 
+
  
 
|-
 
|-
Line 306: Line 257:
  
  
−
Instead of re-projecting the entire layer, we will re-project some features.
+
Instead of re-projecting the entire '''layer''', we will re-project some features.
  
 
|-
 
|-
−
|| On top-right corner of the tool bar,
+
|| On top-right corner of the tool bar >> click on '''Select features by area or single click '''tool.
−
 
+
−
Click on the '''Select features by area or single click '''tool.
+
−
 
+
−
 
+
−
Click on the black triangle next to this tool.
+
−
 
+
−
 
+
−
From the drop down choose '''Select features'''.
+
 
|| On top-right corner of the tool bar,  
 
|| On top-right corner of the tool bar,  
  
Line 323: Line 266:
 
Click on '''Select features by area or single click '''tool.
 
Click on '''Select features by area or single click '''tool.
  
 +
|-
 +
||Click on the black triangle next to this tool.
 +
||Click on the black triangle next to this tool.
  
−
Click on the black triangle next to this tool.  
+
|-
−
 
+
||Drop down >> choose '''Select features'''.
−
 
+
||From the drop down choose '''Select features'''.
−
From the drop down choose '''Select features'''.
+
−
 
+
−
 
+
−
 
+
  
 
|-
 
|-
 
|| On the canvas, on the world map, click on '''United States of America.'''
 
|| On the canvas, on the world map, click on '''United States of America.'''
−
|| On the world map displayed on canvas,  
+
|| On the world map displayed on '''canvas''', click on the '''United States of America''' feature to select it.
  
  
−
click on The '''United States of America''' feature to select it.
+
Note that, the''' United States of America '''is shown in a different color.
−
 
+
−
 
+
−
Note that,
+
−
 
+
−
The''' United States of America '''is shown in a different color.
+
  
 
|-
 
|-
 
|| Cursor on the map.
 
|| Cursor on the map.
−
|| We will now change the '''projected coordinate system''' of this layer and save.  
+
|| We will now change the '''projected coordinate system''' of this '''layer''' and save.  
−
 
+
−
 
+
−
 
+
  
 
|-
 
|-
 
|| Right click on '''ne_10m_admin_0_countries'''
 
|| Right click on '''ne_10m_admin_0_countries'''
−
|| Right-click on the layer name in the '''Layers Panel'''.
+
|| Right-click on the '''layer''' name in the '''Layers Panel'''.
  
 
|-
 
|-
 
|| Click on '''Save As''' option
 
|| Click on '''Save As''' option
−
|| Scroll down, Select '''Save As''' option.
+
|| Scroll down, select '''Save As''' option.
  
 
|-
 
|-
−
|| '''Save Vector Layer as '''Dialog box opens.
+
|| '''Save Vector Layer as '''dialog box opens.
  
  
  
−
|| '''Save Vector Layer as... '''Dialog box opens.
+
|| '''Save Vector Layer as... '''dialog box opens.
  
  
−
The default '''format '''option is '''ESRI shape file,''' leave it as such.
+
The default '''format '''option is '''ESRI Shapefile.'''  
 +
 
 +
Leave it as such.
  
 
|-
 
|-
Line 376: Line 312:
 
|| '''Save layer as... '''dialog-box opens.
 
|| '''Save layer as... '''dialog-box opens.
  
−
In the name text box type the layer as '''USA-1.shp.'''
+
In the name text box, type the '''layer''' as '''USA-1.shp.'''
 
|| '''Save layer as... '''dialog-box opens.
 
|| '''Save layer as... '''dialog-box opens.
  
  
−
Name the output layer as '''USA-1.shp.'''
+
Name the output '''layer''' as '''USA-1.shp.'''
−
 
+
−
 
+
−
 
+
  
 
|-
 
|-
Line 391: Line 324:
 
Click on '''Save''' button.  
 
Click on '''Save''' button.  
 
|| Find a suitable location to save.
 
|| Find a suitable location to save.
−
 
  
 
I will save it on '''Desktop'''
 
I will save it on '''Desktop'''
  
−
 
+
Click on '''Save''' button at the bottom.  
−
Click on '''Save''' button.  
+
  
 
|-
 
|-
Line 403: Line 334:
  
 
Point to '''File name '''text box.
 
Point to '''File name '''text box.
−
|| In the '''Save Vector Layer''' '''as....''' dialog-box,
+
|| In the '''Save Vector Layer as....''' dialog-box, the '''file path''' appears in the '''File name''' text box.
−
 
+
−
 
+
−
The file path appears in the '''File name''' text box.
+
−
 
+
−
 
+
−
 
+
  
 
|-
 
|-
−
|| Click select CRS button next to CRS text box.
+
|| Click select '''CRS''' button next to '''CRS''' text box.
  
  
  
−
|| We will choose the new projection for this layer.
+
|| We will choose the new '''projection''' for this '''layer'''.
  
  
Line 422: Line 347:
  
 
|-
 
|-
−
|| In the '''Coordinate Reference System Selector''' dialog box,  
+
|| In the '''Coordinate Reference System Selector''' dialog box, type '''North America'''
  
  
−
Type '''North America'''
+
||  
−
 
+
*In the '''Coordinate Reference System Selector''',
−
 
+
*In the '''Filter search box''', enter '''North America'''  
−
 
+
−
|| In the '''Coordinate Reference System Selector''',
+
−
 
+
−
 
+
−
In the '''Filter '''search box. Enter '''North America'''  
+
  
 
|-
 
|-
 
|| Click '''North_America_Albers_Equal_Area_Conic'''
 
|| Click '''North_America_Albers_Equal_Area_Conic'''
  
−
Click on '''OK''' button.
 
  
  
−
 
+
||  
−
|| Under '''Coordinate reference systems''' of the world,
+
*Under '''Coordinate reference systems''' of the world,  
−
 
+
*Under heading '''Projected Coordinate System, '''
−
 
+
*Scroll through the results.
−
Under heading '''Projected Coordinate System, '''Scroll through the results.''' '''
+
−
 
+
−
 
+
−
Select, '''North_America_Albers_Equal_Area_Conic (EPSG:102008)''' projection.
+
−
 
+
  
  
 +
Select, '''North_America_Albers_Equal_Area_Conic (EPSG:102008) projection'''.
  
 
|-
 
|-
 
|| Click on '''OK''' button.
 
|| Click on '''OK''' button.
−
|| Click on '''OK''' button.
+
|| Click on '''OK''' button at the bottom.
  
 
|-
 
|-
−
|| In the Save vector layer as... dialog-box, cursor on '''CRS''' drop down box.
+
|| In the '''Save vector layer as...''' dialog-box, cursor on '''CRS''' drop down box.
 
|| In the '''CRS''' drop down box, the newly selected '''CRS''' is shown.
 
|| In the '''CRS''' drop down box, the newly selected '''CRS''' is shown.
  
 
|-
 
|-
−
|| In the '''Save Vector Layer''' '''as''' dialog-box,
+
|| In the '''Save Vector Layer''' '''as dialog-box,
  
  
 
Click on the check box next to '''Save only selected features.'''
 
Click on the check box next to '''Save only selected features.'''
−
|| Click on the check box to check '''Save only selected features '''option'''.'''
+
|| Click on the check box to check '''Save only selected features '''option.
  
  
−
This will ensure that only the selected feature gets re-projected and exported.
+
This will ensure that only the selected '''feature''' gets '''re-projected''' and '''exported'''.
  
 
|-
 
|-
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|-
 
|-
 
|| In the '''Save Vector Layer''' '''as...''' dialog-box, click on '''OK '''button  
 
|| In the '''Save Vector Layer''' '''as...''' dialog-box, click on '''OK '''button  
−
|| Click on '''OK '''button  
+
|| Click on '''OK '''button at the bottom.
  
 
|-
 
|-
Line 486: Line 401:
  
 
Cursor on '''Layers panel'''.
 
Cursor on '''Layers panel'''.
−
|| The re-projected layer gets loaded,  
+
|| The '''re-projected layer''' gets loaded, in a different color.
  
−
in a different color.
 
  
 +
These two '''layers''' are now in different '''projections'''.
  
−
These two layers are now in different projections.
 
  
−
 
+
Observe that, on '''Layers Panel,''' you can now see 2 entries.
−
Observe that, on '''Layers Panel''' you can now see 2 entries.
+
  
 
|-
 
|-
Line 501: Line 414:
  
 
'''Point to OTF next to EPSG:4326.'''
 
'''Point to OTF next to EPSG:4326.'''
−
|| Notice that the new '''united states '''layer overlays perfectly on top of the world map layer.
+
|| Notice that the new '''United States layer''' overlays perfectly on top of the '''world map layer'''.
  
  
−
This is because '''QGIS''' has a feature called '''On-the-fly CRS transformation.'''
+
This is because '''QGIS''' has a '''feature''' called '''On-the-fly CRS transformation.'''
  
  
−
The projection text at the bottom-right of '''QGIS''' window has the words,  
+
The '''projection''' text at the bottom-right of '''QGIS''' window has the words, '''OTF '''next to '''EPSG:4326'''.
−
 
+
−
 
+
−
'''OTF '''next to '''EPSG:4326'''.
+
  
 
|-
 
|-
−
|| At the bottom-right corner, click on EPSG:4326.
+
|| At the bottom-right corner, click on '''EPSG:4326'''.
  
  
Line 520: Line 430:
  
  
−
Click on the Current CRS text, '''EPSG:4326,''' at the bottom-right corner of the status bar.
+
Click on the '''Current CRS''' text, '''EPSG:4326,''' at the bottom-right corner of the '''status''' bar.
−
 
+
−
 
+
−
 
+
  
 
|-
 
|-
Line 540: Line 447:
  
  
−
Click on '''OK '''button.
+
Click on '''OK '''button at the bottom.
  
 
|-
 
|-
 
|| Cursor on the map.
 
|| Cursor on the map.
−
|| Back in the main QGIS window, you will see the world map disappear.
+
|| Back in the '''main QGIS''' window, you will see the world map disappear.
  
  
−
You can see only United states map on the canvas.
+
You can see only '''United States''' map on the '''canvas'''.
  
  
−
This is because the Projected CRS for this layer changed to '''Albers Projection.'''
+
This is because the '''Projected CRS''' for this '''layer''' changed to '''Albers Projection.'''
  
 
|-
 
|-
Line 557: Line 464:
  
 
Select zoom to layer
 
Select zoom to layer
−
|| The coordinates and scale are different now.
+
|| The '''coordinates''' and scale are different now.
  
  
−
Right-click the''' united states '''layer in the '''Layers Panel.'''
+
Right-click the''' United States layer''' in the '''Layers Panel.'''
  
  
Line 566: Line 473:
  
  
−
Now you will see the '''United States''' in the selected projection.
+
Now you will see the '''United States''' in the selected '''projection'''.
  
 
|-
 
|-
Line 577: Line 484:
  
 
Turn-on the''' Enable ‘on the fly’ CRS transformation''' option.
 
Turn-on the''' Enable ‘on the fly’ CRS transformation''' option.
−
 
−
 
−
 
  
 
|-
 
|-
−
|| Under the heading '''Recently used Coordinate Reference Systems,'''
+
|| Under the heading '''Recently used Coordinate Reference Systems,''' select '''WGS 84.'''
−
 
+
−
 
+
−
Select '''WGS 84.'''
+
  
  
 
Click on''' OK '''button.
 
Click on''' OK '''button.
−
|| Under the heading '''Recently used Coordinate Reference Systems,'''
+
|| Under the heading '''Recently used Coordinate Reference Systems,''' select '''WGS 84'''.
  
 +
And click on '''OK '''button at the bottom.
  
−
Select '''WGS 84''' and click on '''OK '''button.
 
  
−
 
+
The display on the '''canvas''' will return to its previous state with world map.
−
The display on the canvas will return to its previous state with world map.
+
  
 
|-
 
|-
Line 601: Line 501:
  
  
−
 
+
|| To delete the '''vector layer''' from the '''dataset''', right-click on the name in '''Layers panel'''.  
−
|| To delete the vector layer from the dataset,
+
−
 
+
−
 
+
−
Right-click on the name in '''Layers panel'''.  
+
−
 
+
−
 
+
−
 
+
  
 
|-
 
|-
Line 618: Line 511:
  
  
−
A prompt appears to conform the action, click on '''OK''' button.
+
A '''prompt''' appears to confirm the action.
 +
 
 +
Click on '''OK''' button.
  
 
|-
 
|-
 
|| Cursor on the layers panel.
 
|| Cursor on the layers panel.
−
|| Observe that the layer is removed from the dataset.
+
|| Observe that the '''layer''' is removed from the '''dataset'''.
  
 
|-
 
|-
Line 632: Line 527:
 
In this tutorial we have learnt to
 
In this tutorial we have learnt to
  
−
* Add layers to '''projections''' in QGIS.
+
* Add '''layers''' to '''projections''' in '''QGIS'''.
−
* View metadata information for layers.
+
* View '''metadata''' information for '''layers'''.
−
 
+
* Save selected '''features''' from a '''layer''' to a new '''layer'''.
−
* Save selected features from a layer to a new layer.
+
* '''Re-project''' and '''overlay data layers''' of different '''projections''' together.
−
* Re-project and overlay data layers of different '''projections''' together.
+
−
 
+
−
 
+
  
 
|-
 
|-
Line 644: Line 536:
  
 
Assignment
 
Assignment
−
|| As an Assignment
+
|| As an Assignment:
−
 
+
−
Project The '''United States '''with '''North_America_Lambert_Conformal_Conic projection''' and observe the difference.
+
−
 
+
−
Re-project the entire world map layer into '''World Mecator projection''' system.
+
  
 +
*'''Project''' The '''United States '''with '''North_America_Lambert_Conformal_Conic projection'''
 +
*and observe the difference.
  
 +
*'''Re-project''' the entire world map '''layer''' into '''World Mecator projection''' system.
  
 
|-
 
|-

Revision as of 09:08, 27 August 2018

Visual Cue Narration
Slide Number 1

Title Slide

Welcome to this tutorial on Coordinate Reference System in QGIS.
Slide Number 2

Learning Objectives

In this tutorial, we will learn to,
  • Add layers to projections in QGIS.
  • View metadata information for layers.
  • Save selected features from a layer to a new layer.
  • Re-project and overlay data layers of different projections together.
Slide Number 3

System Requirement

To record this tutorial I am using,
  • Ubuntu Linux OS version 16.04
  • QGIS version 2.18
Slide Number 4

Pre-requisites

  • Basic knowledge about GIS.
  • Please view pre-requisite tutorial in this series.
To follow this tutorial you should have basic knowledge about GIS.


Please view previous tutorial in this series.

Slide Number 5

Coordinate Reference systems

About Coordinate Reference Systems,


Coordinate Reference Systems are of two types,

  • Geographic coordinate system
  • Projected Coordinate System
Slide Number 5

Coordinate Reference systems

Most widely used geographic coordinate system is WGS 84.

Most widely used projected coordinate system is UTM.

Click on QGIS icon to open the interface.


Cursor on Canvas.

Here I have opened QGIS interface.


On the canvas, world map with country administration boundaries is displayed.

Slide Number 6

World Map File

Demonstration on how to download the map and display in QGIS is explained in the prerequisite tutorial.


Please view the pre-requisite tutorial.


This file can also be downloaded from the Code files link.

Cursor on layers panel on name of the map file. On the left-side of the canvas, you will see Layers Panel, with file name of the world map as a layer.
Cursor on the canvas. By default Layers Panel is enabled here.


If not, we can enable or disable the Layers Panel using View menu.

Click on View tool on the Tool bar.


Click on View menu on the menu bar.


Scroll down and select Panels option.

Scroll down and select Panels option.

From the sub-menu, click on Layer Panel.

Sub-menu shows a list of panel names.


Click on Layer Panel option to enable or disable the panel.

Drag the boundary with the mouse. We can adjust the size of the panel by dragging the boundary.
Right-click on the layer name in Layers Panel.


If you wish to change the color of the map, right-click on the layer name in the Layers Panel.
Scroll-down the context menu and select Styles option. Scroll-down the context menu and select Styles option.
Rotate the vertex of the color triangle to choose the color.


Sub-menu shows a color triangle .


Choose the color by rotating the vertex of the color triangle.

Click anywhere on the canvas. Click anywhere on the canvas to close the context menu.
Cursor on Coordinate label and text box.


At the bottom-left corner, on the status bar of QGIS window, you will notice
  • the label Coordinate
  • and a text box with numbers.
Highlight X and Y coordinates. (Editing stage) Values of X and Y coordinates for a particular location are shown in this text box.
Move the cursor over the map.


Point

Move the cursor over the map.


Observe, that the values of X and Y coordinates change with the location of the cursor.

Cursor on Render option. By default Render option is checked on the status bar.


Leave it as such.

Point towards EPSG:4326(OTF) on the bottom-right corner of the status bar. On the status bar, at the bottom-right corner, you will see another label, Current CRS.


This code represents the current Projection Coordinate Reference System.

To determine a layer’s projection, we can look into the metadata.
Right click on the Layers Panel, ne_10m_admin_0_countries On the Layers Panel, right-click on the layer name.
From the context menu, select Properties.


From the context menu, select Properties.


Layer Properties dialog-box opens.

Click on Metadata option in Layer dialog-box.


Click on back arrow next to properties.

Scroll down.

In the dialog-box, on the left-side panel, click on Metadata option.


Under Properties section, scroll down the slider.

Point to heading, Layer Spatial Reference System.


Point to WGS84.


At the bottom,
  • under heading, Layer Spatial Reference System,
  • you will see the definition for this projection.


It shows WGS84 as geographic coordinate system.

Click Ok button Click on Ok button at the bottom, to close the dialog box.
Let us now add layers to the map and change the projection.
Slide Number 7

Data layers

About data layers.
  • Usually geographical data is stored in layers in a GIS workspace.
  • Each layer has data stored in its attribute table.
  • Many layers can represent data of the same geographical location.
Back to the QGIS interface.
Cursor on the QGIS canvas. Now let us see how we can change the layer’s projection.


This operation is called Re-Projection.


Instead of re-projecting the entire layer, we will re-project some features.

On top-right corner of the tool bar >> click on Select features by area or single click tool. On top-right corner of the tool bar,


Click on Select features by area or single click tool.

Click on the black triangle next to this tool. Click on the black triangle next to this tool.
Drop down >> choose Select features. From the drop down choose Select features.
On the canvas, on the world map, click on United States of America. On the world map displayed on canvas, click on the United States of America feature to select it.


Note that, the United States of America is shown in a different color.

Cursor on the map. We will now change the projected coordinate system of this layer and save.
Right click on ne_10m_admin_0_countries Right-click on the layer name in the Layers Panel.
Click on Save As option Scroll down, select Save As option.
Save Vector Layer as dialog box opens.


Save Vector Layer as... dialog box opens.


The default format option is ESRI Shapefile.

Leave it as such.

Click on Browse button. Click on Browse button next to File name text box.
Save layer as... dialog-box opens.

In the name text box, type the layer as USA-1.shp.

Save layer as... dialog-box opens.


Name the output layer as USA-1.shp.

Click on Desktop option.


Click on Save button.

Find a suitable location to save.

I will save it on Desktop

Click on Save button at the bottom.

In the Save Vector Layer as... dialog-box.


Point to File name text box.

In the Save Vector Layer as.... dialog-box, the file path appears in the File name text box.
Click select CRS button next to CRS text box.


We will choose the new projection for this layer.


Next to the CRS drop down box, click on Select CRS button.

In the Coordinate Reference System Selector dialog box, type North America


  • In the Coordinate Reference System Selector,
  • In the Filter search box, enter North America
Click North_America_Albers_Equal_Area_Conic


  • Under Coordinate reference systems of the world,
  • Under heading Projected Coordinate System,
  • Scroll through the results.


Select, North_America_Albers_Equal_Area_Conic (EPSG:102008) projection.

Click on OK button. Click on OK button at the bottom.
In the Save vector layer as... dialog-box, cursor on CRS drop down box. In the CRS drop down box, the newly selected CRS is shown.
In the Save Vector Layer as dialog-box,


Click on the check box next to Save only selected features.

Click on the check box to check Save only selected features option.


This will ensure that only the selected feature gets re-projected and exported.

Cursor on , Add saved file to map. Here, by default, Add saved file to map option is checked.


If not, click on the check box to check this option.

In the Save Vector Layer as... dialog-box, click on OK button Click on OK button at the bottom.
Point on united states outline.


Cursor on Layers panel.

The re-projected layer gets loaded, in a different color.


These two layers are now in different projections.


Observe that, on Layers Panel, you can now see 2 entries.

untick enable on the fly CRS transformation


Point to OTF next to EPSG:4326.

Notice that the new United States layer overlays perfectly on top of the world map layer.


This is because QGIS has a feature called On-the-fly CRS transformation.


The projection text at the bottom-right of QGIS window has the words, OTF next to EPSG:4326.

At the bottom-right corner, click on EPSG:4326.


Select United-States layer in the Layers Panel by clicking on it.


Click on the Current CRS text, EPSG:4326, at the bottom-right corner of the status bar.

Cursor on Project Properties CRS dialog-box. Project Properties CRS dialog-box opens.


Let us turn-off the Enable on-the-fly CRS transformation and see what happens.

Uncheck Enable on the fly CRS transformation check box,


Uncheck Enable on the fly CRS transformation check box, by clicking on it.


Click on OK button at the bottom.

Cursor on the map. Back in the main QGIS window, you will see the world map disappear.


You can see only United States map on the canvas.


This is because the Projected CRS for this layer changed to Albers Projection.

Right click on USA-1.shp layer.


Select zoom to layer

The coordinates and scale are different now.


Right-click the United States layer in the Layers Panel.


Select Zoom to Layer option.


Now you will see the United States in the selected projection.

Click on EPSG


Tick Enable on the fly CRS transformation.

Again, click on the Current CRS text to open Project Properties dialog-box.


Turn-on the Enable ‘on the fly’ CRS transformation option.

Under the heading Recently used Coordinate Reference Systems, select WGS 84.


Click on OK button.

Under the heading Recently used Coordinate Reference Systems, select WGS 84.

And click on OK button at the bottom.


The display on the canvas will return to its previous state with world map.

Right-click on USA-1.shp in Layers panel.


To delete the vector layer from the dataset, right-click on the name in Layers panel.
Click on Remove option from the context menu.


Click on OK button in the dialog-box (Remove Layers or Groups)

From the context menu, click on Remove option.


A prompt appears to confirm the action.

Click on OK button.

Cursor on the layers panel. Observe that the layer is removed from the dataset.
Slide Number 10

Summary

Let us summarize,

In this tutorial we have learnt to

  • Add layers to projections in QGIS.
  • View metadata information for layers.
  • Save selected features from a layer to a new layer.
  • Re-project and overlay data layers of different projections together.
Slide Number 11

Assignment

As an Assignment:
  • Project The United States with North_America_Lambert_Conformal_Conic projection
  • and observe the difference.
  • Re-project the entire world map layer into World Mecator projection system.
Show completed assignments. Your completed assignment should look like this.
Slide Number 12

About Spoken Tutorial project

The video at the following link summarizes the Spoken Tutorial project.

Please download and watch it.


Slide Number 13

Spoken Tutorial workshops

The Spoken Tutorial Project team:

conducts workshops using spoken tutorials and

gives certificates on passing online tests.

For more details, please write to us.

Slide number 14

Forum for specific questions:


Do you have questions in THIS Spoken Tutorial?

•Please visit this site

•Choose the minute and second where you have the question

•Explain your question briefly

•Someone from our team will answer them


Please post your timed queries on this forum.
Slide Number 16:

Acknowledgement

Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at this link.

This tutorial is contributed by Prajwal. M from Sahyadri college of Engineering and Snehalatha from IIT Bombay.

Thank you for joining

Contributors and Content Editors

Madhurig, Nancyvarkey, Snehalathak

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