PoojaMoolya: Created page with "{|border=1 ||'''Time''' ||'''Narration''' |- ||00:01 || Welcome to this tutorial on '''Coordinate Reference System''' in ''' QGIS'''. |- || 00:07 || In this tutorial, we wi..."

2020-09-15T05:28:04Z

Created page with "{|border=1 ||'''Time''' ||'''Narration''' |- ||00:01 || Welcome to this tutorial on '''Coordinate Reference System''' in ''' QGIS'''. |- || 00:07 || In this tutorial, we wi..."

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{|border=1
||'''Time'''
||'''Narration'''

|-
||00:01
|| Welcome to this tutorial on '''Coordinate Reference System''' in ''' QGIS'''.

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|| 00:07
|| In this tutorial, we will learn to,

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|| 00:10
||Add layers to '''projections''' in '''QGIS'''.

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|| 00:15
||View '''metadata''' information for '''layers'''.

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|| 00:19
||Save selected features from a '''layer''' to a new '''layer'''.

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|| 00:24
||Re-project and overlay '''data layers''' of different '''projections''' together.

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|| 00:30
|| To record this tutorial I am using,

'''Ubuntu Linux OS''' version 16.04, '''QGIS''' version 2.18

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|| 00:42
|| To follow this tutorial you should have basic knowledge about '''GIS'''.

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|| 00:49
||Please view previous tutorial in this series.

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|| 00:54
|| About '''Coordinate Reference Systems''',

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|| 00:57
||'''Coordinate Reference Systems''' are of two types,

'''Geographic coordinate system''', and '''Projected Coordinate System'''

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|| 01:06
||Most widely used '''geographic coordinate system''' is '''WGS 84'''.

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|| 01:12
||Most widely used '''projected coordinate system''' is '''UTM'''.

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|| 01:18
|| Here I have opened '''QGIS''' interface.

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|| 01:23
||On the '''canvas''', world map with country administration boundaries is displayed.

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|| 01:30
|| Demonstration on how to download the map and display in '''QGIS''' is explained in the prerequisite tutorial.

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|| 01:39
||Please view the pre-requisite tutorial.

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|| 01:43
||This file can also be downloaded from the '''Code files''' link.

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|| 01:48
|| On the left-side of the '''canvas''', you will see '''Layers Panel''', with file name of the world map as a '''layer'''.

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|| 01:57
|| By default '''Layers Panel''' is enabled here.

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|| 02:02
||If not, we can enable or disable the '''Layers Panel''' using '''View''' menu.

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|| 02:08
|| Click on '''View''' menu on the '''menu''' bar.

Scroll down and select '''Panels '''option.

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|| 02:16
|| Sub-menu shows a list of '''panel''' names.

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|| 02:21
||Click on '''Layer Panel''' option to enable or disable the '''panel'''.

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|| 02:27
|| We can adjust the size of the '''panel''' by dragging the boundary.

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|| 02:32
|| If you wish to change the color of the map, right-click on the '''layer''' name in the '''Layers Panel.'''

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|| 02:39
|| Scroll-down the '''context menu''' and select '''Styles''' option.

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||02:44
||Sub-menu shows a color triangle .

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|| 02:48
||Choose the color by rotating the vertex of the color triangle.

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|| 02:53
|| Click anywhere on the '''canvas''' to close the context menu.

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|| 02:58
|| At the bottom-left corner, on the '''status''' bar of '''QGIS''' window, you will notice the label '''Coordinate ''' and a text box with numbers.

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|| 03:09
|| Values of '''X ''' and '''Y coordinates''' for a particular location are shown in this text box.

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|| 03:17
|| Move the cursor over the map.

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|| 03:20
||Observe, that the values of '''X''' and '''Y coordinates''' change with location of the cursor.

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|| 03:28
|| By default '''Render '''option is checked on the '''status bar'''.

Leave it as such.

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|| 03:37
|| On the '''status bar''', at the bottom-right corner, you will see another label, '''Current CRS'''

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|| 03:44
||This code represents the current '''Projection Coordinate Reference System.'''

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|| 03:50
|| To determine a '''layer’s projection''', we can look into the '''metadata'''.

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|| 03:56
|| On the '''Layers Panel''', right-click on the '''layer''' name.

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|| 04:01
|| From the context menu, select '''Properties'''.

'''Layer Properties''' dialog-box opens.

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|| 04:09
|| In the dialog-box, on the left-side panel, click on '''Metadata''' option.

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|| 04:15
||Under '''Properties '''section, scroll down the slider.

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|| 04:20
|| At the bottom, under heading, '''Layer Spatial Reference System,''' you will see the definition for this projection.

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|| 04:29
||It shows '''WGS84 '''as '''geographic coordinate system.'''

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|| 04:35
|| Click on '''Ok''' button at the bottom, to close the dialog box.

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|| 04:41
|| Let us now add '''layers''' to the map and change the '''projection'''.

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|| 04:47
|| About '''data layers'''.

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|| 04:50
|| Usually '''geographical data''' is stored in '''layers''' in a '''GIS''' workspace.

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|| 04:57
||Each '''layer''' has '''data''' stored in its '''attribute table'''.

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|| 05:02
||Many '''layers''' can represent '''data''' of the same geographical location.

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|| 05:08
|| Back to the '''QGIS''' interface.

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|| 05:12
|| Now let us see how we can change the '''layer’s projection.'''

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|| 05:17
||This operation is called '''Re-Projection'''.

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|| 05:21
||Instead of re-projecting the entire '''layer''', we will re-project some features.

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|| 05:27
|| On top-right corner of the tool bar, click on '''Select features by area or single click '''tool.

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||05:35
||Click on the black triangle next to this tool.

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||05:39
||From the drop down choose '''Select features'''.

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|| 05:44
|| On the world map displayed on '''canvas''', click on the '''United States of America''' feature to select it.

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|| 05:52
||Note that, the '''United States of America''' is shown in a different color.

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|| 05:58
|| We will now change the '''projected coordinate system''' of this '''layer''' and save.

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|| 06:04
|| Right-click on the '''layer''' name in the '''Layers Panel'''.

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|| 06:08
|| Scroll down, select '''Save As''' option.

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|| 06:12
|| '''Save Vector Layer as... '''dialog box opens.

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|| 06:17
||The default '''format '''option is '''ESRI Shapefile.'''

Leave it as such.

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|| 06:26
|| Click on '''Browse button''' next to '''File name '''text box.

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|| 06:31
|| '''Save layer as... '''dialog-box opens.

Name the output '''layer''' as '''USA-1.shp.'''

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|| 06:41
|| Find a suitable location to save.

I will save it on '''Desktop'''

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|| 06:48
||Click on '''Save''' button at the bottom.

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|| 06:52
|| In the '''Save Vector Layer as....''' dialog-box, the '''file path''' appears in the '''File name''' text box.

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|| 06:59
|| We will choose the new '''projection''' for this '''layer'''.

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|| 07:03
||Next to the '''CRS''' drop down box, click on '''Select CRS '''button.

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|| 07:10
|| In the '''Coordinate Reference System Selector''', in the '''Filter search box''', enter '''North America'''

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|| 07:17
|| Under '''Coordinate reference systems''' of the world, under heading '''Projected Coordinate System, ''' scroll through the results.

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|| 07:27
||Select, '''North_America_Albers_Equal_Area_Conic (EPSG:102008) projection'''.

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||07:37
|| Click on '''OK''' button at the bottom.

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|| 07:41
|| In the '''CRS''' drop down box, the newly selected '''CRS''' is shown.

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|| 07:47
|| Click on the check box to check '''Save only selected features '''option.

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|| 07:53
||This will ensure that only the selected '''feature''' gets '''re-projected''' and '''exported'''.

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|| 08:00
|| Here, by default, '''Add saved file to map '''option is checked.

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|| 08:06
||If not, click on the check box to check this option.

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|| 08:11
|| Click on '''OK '''button.

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|| 08:14
|| The '''re-projected layer''' gets loaded, in a different color.

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|| 08:19
||These two '''layers''' are now in different '''projections'''.

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|| 08:24
||Observe that, on '''Layers Panel,''' you can now see 2 entries.

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|| 08:30
|| Notice that the new '''United States layer''' overlays perfectly on top of the '''world map layer'''.

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|| 08:38
||This is because '''QGIS''' has a '''feature''' called '''On-the-fly CRS transformation.'''

|-
|| 08:45
||The '''projection''' text at the bottom-right corner of '''QGIS''' window has the words, '''OTF''' next to '''EPSG:4326'''.

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|| 08:56
|| Select the '''United-States''' layer in the '''Layers Panel '''by clicking on it.

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|| 09:02
||Click on the '''Current CRS''' text, '''EPSG:4326,''' at the bottom-right corner of the '''status''' bar.

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|| 09:11
|| '''Project Properties CRS''' dialog-box opens.

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|| 09:16
||Let us turn-off the '''Enable on-the-fly CRS transformation''' and see what happens.

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|| 09:23
|| Uncheck the '''Enable on the fly CRS transformation '''check box, by clicking on it.

Click on '''OK '''button at the bottom.

|-
|| 09:34
|| Back in the '''main QGIS''' window, you will see the world map disappear.

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|| 09:40
||You can see only the '''United States''' map on the '''canvas'''.

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|| 09:45
||This is because the '''Projected CRS''' for this '''layer''' changed to '''Albers Projection.'''

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|| 09:52
|| The '''coordinates''' and scale are different now.

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|| 09:56
||Right-click the '''United States layer''' in the '''Layers Panel'''.

|-
|| 10:01
||Select '''Zoom to Layer''' option.

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|| 10:05
||Now you will see the '''United States''' in the selected '''projection'''.

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|| 10:10
|| Again, click on the '''Current CRS''' text to open '''Project Properties''' dialog-box.

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|| 10:17
||Turn-on the''' Enable ‘on the fly’ CRS transformation''' option.

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|| 10:23
|| Under the heading '''Recently used Coordinate Reference Systems,''' select '''WGS 84'''.

At the bottom, click on '''OK '''button.

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|| 10:35
||The display on the '''canvas''' will return to its previous state with world map.

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|| 10:41
|| To delete the '''vector layer''' from the '''dataset''', right-click on the name in the '''Layers panel'''.

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|| 10:48
|| From the '''context menu''', click on '''Remove''' option.

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|| 10:52
||A '''prompt''' appears to confirm the action.

Click on '''OK''' button.

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|| 10:59
|| Observe that the '''layer''' is removed from the '''dataset'''.

|-
||11:04
|| Let us summarize,

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|| 11:07
||In this tutorial we have learnt to

Add '''layers''' to '''projections''' in '''QGIS'''.

|-
|| 11:15
||View '''metadata''' information for '''layers'''.

|-
|| 11:19
||Save selected '''features''' from a '''layer''' to a new '''layer'''.

|-
|| 11:24
||'''Re-project''' and '''overlay data layers''' of different '''projections''' together.

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|| 11:30
|| As an Assignment:

'''Project''' The '''United States '''with '''North_America_Lambert_Conformal_Conic projection''' and observe the difference.

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|| 11:43
|| '''Re-project''' the entire world map '''layer''' into '''World Mercator projection''' system.

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|| 11:50
|| Your completed assignment should look like this.

|-
|| 11:55
||The video at the following link summarizes the Spoken Tutorial project. Please download and watch it.
|-
|| 12:03
|| The Spoken Tutorial Project team: conducts workshops and

Gives certificates on passing online tests. For more details, please write to us.

|-
|| 12:15
|| Please post your timed queries on this forum.

|-
||12:19
|| Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at this link.

|-
|| 12:31
|| This tutorial is contributed by Prajwal. M from Sahyadri college of Engineering and Snehalatha from IIT Bombay.

Thank you for joining
|-
|}

QGIS/C2/Coordinate-Reference-Systems/English-timed - Revision history

PoojaMoolya: Created page with "{|border=1 ||'''Time''' ||'''Narration''' |- ||00:01 || Welcome to this tutorial on '''Coordinate Reference System''' in ''' QGIS'''. |- || 00:07 || In this tutorial, we wi..."