Features at a Glance

After a first and simple sample session in Section Getting Started we now want to give you a more detailed overview of the features of QGIS. Most features presented in the following chapters will be explained and described in their own sections later in the manual.

Starting and Stopping QGIS

In Section Sample Session you already learned how to start QGIS. We will repeat this here and you will see that QGIS also provides further command line options.

  • nix Assuming that QGIS is installed in the PATH, you can start QGIS by typing: qgis at a command prompt or by double clicking on the QGIS application link (or shortcut) on the desktop or in the application menu.
  • win Start QGIS using the Start menu or desktop shortcut, or double click on a QGIS project file.
  • osx Double click the icon in your Applications folder. If you need to start QGIS in a shell, run /path-to-installation-executable/Contents/MacOS/Qgis.

To stop QGIS, click the menu options nix win File osx QGIS ‣ Quit, or use the shortcut Ctrl+Q.

Command Line Options

command line options

nix QGIS supports a number of options when started from the command line. To get a list of the options, enter qgis ---help on the command line. The usage statement for QGIS is:

qgis --help
Quantum GIS - 1.7.0-Wroclaw 'Wroclaw' (exported)
Quantum GIS (QGIS) is a viewer for spatial data sets, including
raster and vector data.
Usage: qgis [options] [FILES]
  options:
        [--snapshot filename]           emit snapshot of loaded datasets to given file
        [--width width]                 width of snapshot to emit
        [--height height]               height of snapshot to emit
        [--lang language]               use language for interface text
        [--project projectfile]         load the given QGIS project
        [--extent xmin,ymin,xmax,ymax]  set initial map extent
        [--nologo]                      hide splash screen
        [--noplugins]                   don't restore plugins on startup
        [--optionspath path]            use the given QSettings path
        [--configpath path]             use the given path for all user configuration
        [--help]                        this text

  FILES:
    Files specified on the command line can include rasters,
    vectors, and QGIS project files (.qgs):
     1. Rasters - Supported formats include GeoTiff, DEM
        and others supported by GDAL
     2. Vectors - Supported formats include ESRI Shapefiles
        and others supported by OGR and PostgreSQL layers using
        the PostGIS extension

Note

Example Using command line arguments You can start QGIS by specifying one or more data files on the command line. For example, assuming you are in the qgis_sample_data directory, you could start QGIS with a vector layer and a raster file set to load on startup using the following command: qgis ./raster/landcover.img ./gml/lakes.gml

Command line option ---snapshot

This option allows you to create a snapshot in PNG format from the current view. This comes in handy when you have a lot of projects and want to generate snapshots from your data.

Currently it generates a PNG-file with 800x600 pixels. This can be adapted using the ---width and ---height command line arguments. A filename can be added after ---snapshot.

Command line option ---lang

Based on your locale QGIS, selects the correct localization. If you would like to change your language, you can specify a language code. For example: ---lang=it starts QGIS in italian localization. A list of currently supported languages with language code and status is provided at http://www.qgis.org/wiki/GUI_Translation_Progress

Command line option ---project

Starting QGIS with an existing project file is also possible. Just add the command line option ---project followed by your project name and QGIS will open with all layers loaded described in the given file.

Command line option ---extent

To start with a specific map extent use this option. You need to add the bounding box of your extent in the following order separated by a comma:

--extent xmin,ymin,xmax,ymax

Command line option ---noplugins

If you have trouble at startup with plugins, you can avoid loading them at startup. They will still be available in Plugins Manager after-wards.

Command line option ---optionspath

You can have multiple configurations and decide which one to use when starting QGIS using this option. See subsec_gui_options to check where does the operating system save the settings files. Presently there is no way to specify in which file where to write the settings, therefore you can create a copy of the original settings file and rename it.

Command line option ---configpath

This option is similar to the one above, but furthermore overrides the default path (~/.qgis) for user configuration and forces QSettings to use this directory, too. This allows users to e.g. carry QGIS installation on a flash drive together with all plugins and settings

QGIS GUI

When QGIS starts, you are presented with the GUI as shown below (the numbers 1 through 6 in yellow ovals refer to the six major areas of the interface as discussed below):

../_images/startup.png

QGIS GUI with Alaska sample data (KDE)

Note

Your window decorations (title bar, etc.) may appear different depending on your operating system and window manager.

The QGIS GUI is divided into six areas:

  1. Menu Bar
  1. Map View
  1. Tool Bar
  1. Map Overview
  1. Map Legend
  1. Status Bar

These six components of the QGIS interface are described in more detail in the following sections. Two more sections present keyboard shortcuts and context help.

Toolbars

The toolbars provide access to most of the same functions as the menus, plus additional tools for interacting with the map. Each toolbar item has popup help available. Hold your mouse over the item and a short description of the tool’s purpose will be displayed.

Every menubar can be moved around according to your needs. Additionally every menubar can be switched off using your right mouse button context menu holding the mouse over the toolbars.

Note

Restoring toolbars

If you have accidentally hidden all your toolbars, you can get them back by choosing menu option Settings ‣ Toolbars.

Map Legend

The map legend area lists all the layers in the project. The checkbox in each legend entry can be used to show or hide the layer .. index::layer!visibility A layer can be selected and dragged up or down in the legend to change the z-ordering. Z-ordering means that layers listed nearer the top of the legend are drawn over layers listed lower down in the legend.

Layers in the legend window can be organised into groups. To do so, right click in the legend window and choose Add group. Type in a name for the group and press Enter. Now click on an existing layer and drag it onto the group. Also, if new layers are added to the project while a group is selected, they will automatically be placed in the group.

To bring a layer out of a group you can drag it out, or right click on it and choose Make to toplevel item. Groups can be nested inside other groups.

The checkbox for a group will show or hide all the layers in the group with one click.

The content of the right mouse button context menu depends on whether the selected legend item is a raster or a vector layer. For GRASS vector layers toggle editing is not available. See section grass_digitising for information on editing GRASS vector layers.

  • Right mouse button menu for raster layers
    • Zoom to layer extent
    • Zoom to best scale (100 %)
    • Show in overview
    • Remove}
    • Properties
    • Rename
    • Add Group
    • Expand all
    • Collapse all
  • Right mouse button menu for vector layers
    • Zoom to layer extent
    • Show in overview
    • Remove
    • Open attribute table
    • Toggle editing (not available for GRASS layers)
    • Save as
    • Save selection as
    • Query
    • Properties
    • Rename
    • Add Group
    • Expand all
    • Collapse all
  • Right mouse button menu for layer groups
    • Zoom to group
    • Remove
    • Set group CRS
    • Rename
    • Add Group
    • Expand all
    • Collapse all

It is possible to select more than one Layer or Group at the same time by holding down the Ctrl-Key while selecting the Layers with the left mouse button. You can than move all selected Layers to a new Group at the same time.

You are also able to delete more than one Layer or Group at once by selecting several Layers with the Ctrl - Key and pressing Ctrl D afterwards. This way all selected Layers or Groups will be removed from the Layerlist.

Map View

This is the ‘business end’ of QGIS - maps are displayed in this area! The map displayed in this window will depend on the vector and raster layers you have chosen to load (see sections that follow for more information on how to load layers). The map view can be panned (shifting the focus of the map display to another region) and zoomed in and out. Various other operations can be performed on the map as described in the toolbar description above. The map view and the legend are tightly bound to each other - the maps in view reflect changes you make in the legend area.

Note

Zooming the Map with the Mouse Wheel

You can use the mouse wheel to zoom in and out on the map. Place the mouse cursor inside the map area and roll the wheel forward (away from you) to zoom in and backwards (towards you) to zoom out. The mouse cursor position is the center where the zoom occurs. You can customize the behavior of the mouse wheel zoom using the tab Map tools tab under the Settings ‣ Options menu.

Note

Panning the Map with the Arrow Keys and Space Bar

You can use the arrow keys to pan in the map. Place the mouse cursor inside the map area and click on the right arrow key to pan East, left arrow key to pan West, up arrow key to pan North and down arrow key to pan South. You can also pan the map using the space bar: just move the mouse while holding down space bar.

Map Overview

The map overview panel provides a full extent view of layers added to it. It can be selected under the menu Settings ‣ Panels. Within the view is a rectangle showing the current map extent. This allows you to quickly determine which area of the map you are currently viewing. Note that labels are not rendered to the map overview even if the layers in the map overview have been set up for labeling.

You can add a single layer to the overview by right-clicking on it in the legend and select checkbox Show in overview. You can also add layers to, or remove all layers from the overview using the Overview tools on the toolbar.

If you click and drag the red rectangle in the overview that shows your current extent, the main map view will update accordingly.

Status Bar

The status bar shows you your current position in map coordinates (e.g. meters or decimal degrees) as the mouse pointer is moved across the map view. To the left of the coordinate display in the status bar is a small button that will toggle between showing coordinate position or the view extents of the map view as you pan and zoom in and out.

A progress bar in the status bar shows progress of rendering as each layer is drawn to the map view. In some cases, such as the gathering of statistics in raster layers, the progress bar will be used to show the status of lengthy operations.

If a new plugin or a plugin update is available, you will see a message in the status bar. On the right side of the status bar is a small checkbox which can be used to temporarily prevent layers being rendered to the map view (see Section redraw_events below). The icon |mIconStopRendering| immediately stops the current map rendering process.

At the far right of the status bar you find the EPSG code of the current project CRS and a projector icon. Clicking on this opens the projection properties for the current project.

Note

Calculating the correct Scale of your Map Canvas

When you start QGIS, degrees is the default unit, and it tells QGIS that any coordinate in your layer is in degrees. To get correct scale values, you can either change this to meter manually in the tab General tab under Settings –> Project Properties or you can select a project Coordinate Reference System (CRS) clicking on the |mIconProjectionDisabled| CRS status icon in the lower right-hand corner of the statusbar. In the last case, the units are set to what the project projection specifies, e.g. ‘+units=m’.

Keyboard shortcuts

QGIS provides default keyboard shortcuts for many features. You find them in Section label_menubar below. Additionally the menu option Settings –> Configure Shortcuts allows to change the default keyboard shortcuts and to add new keyboard shortcuts to QGIS features.

introduction/img/en/shortcuts.png:align:center

Configuration is very simple. Just select a feature from the list and click on Change, Set none or Set default. Once you have found your configuration, you can save it as XML file and load it to another QGIS installation.

Context help

When you need help on a specific topic, you can access context help via the Help button available in most dialogs - please note that third-party plugins can point to dedicated web pages.

Rendering

By default, QGIS renders all visible layers whenever the map canvas must be refreshed. The events that trigger a refresh of the map canvas include:

  • Adding a layer
  • Panning or zooming
  • Resizing the QGIS window
  • Changing the visibility of a layer or layers

QGIS allows you to control the rendering process in a number of ways.

Scale Dependent Rendering

Scale dependent rendering allows you to specify the minimum and maximum scales at which a layer will be visible. To set scale dependency rendering, open the Properties dialog by double-clicking on the layer in the legend. On the |tab|`General` tab, set the minimum and maximum scale values and then click on the :guilabel`Use scale dependent rendering` checkbox.

You can determine the scale values by first zooming to the level you want to use and noting the scale value in the QGIS status bar.

Controlling Map Rendering

Map rendering can be controlled in the following ways:

a) Suspending Rendering

To suspend rendering, click the checkbox Render checkbox in the lower right corner of the statusbar. When the checkbox Render box is not checked, QGIS does not redraw the canvas in response to any of the events described in Section redraw_events. Examples of when you might want to suspend rendering include:

  • Add many layers and symbolize them prior to drawing
  • Add one or more large layers and set scale dependency before drawing
  • Add one or more large layers and zoom to a specific view before drawing
  • Any combination of the above

Checking the checkbox Render box enables rendering and causes an immediate refresh of the map canvas.

b) Setting Layer Add Option

You can set an option to always load new layers without drawing them. This means the layer will be added to the map, but its visibility checkbox in the legend will be unchecked by default. To set this option, choose menu option Settings ‣ Options and click on the tab Rendering tab. Uncheck the checkbox By default new layers added to the map should be displayed checkbox. Any layer added to the map will be off (invisible) by default.

Stopping Rendering

To stop the map drawing, press the ESC key. This will halt the refresh of the map canvas and leave the map partially drawn. It may take a bit of time between pressing ESC and the time the map drawing is halted.

Note

It is currently not possible to stop rendering - this was disabled in qt4 port because of User Interface (UI) problems and crashes.

c) Updating the Map Display During Rendering

You can set an option to update the map display as features are drawn. By default, QGIS does not display any features for a layer until the entire layer has been rendered. To update the display as features are read from the datastore, choose menu option Settings ‣ Options click on the tab Rendering tab. Set the feature count to an appropriate value to update the display during rendering. Setting a value of 0 disables update during drawing (this is the default). Setting a value too low will result in poor performance as the map canvas is continually updated during the reading of the features. A suggested value to start with is 500.

d) Influence Rendering Quality

To influence the rendering quality of the map you have 3 options. Choose menu option Settings ‣ Options click on the tab Rendering tab and select or deselect following checkboxes.

  • checkbox Make lines appear less jagged at the expense of some drawing performance
  • checkbox Fix problems with incorrectly filled polygons

Measuring

Measuring works within projected coordinate systems (e.g., UTM) and unprojected data. If the loaded map is defined with a geographic coordinate system (latitude/longitude), the results from line or area measurements will be incorrect. To fix this you need to set an appropriate map coordinate system (See Section Working with Projections). All measuring modules also use the snapping settings from the digitizing module. This is useful, if you want to measure along lines or areas in vector layers.

To select a measure tool click on |mActionMeasure| and select the tool you want to use.

Measure length, areas and angles

|mActionMeasure| QGIS is able to measure real distances between given points according to a defined ellipsoid. To configure this, choose menu option Settings ‣ Options, click on the tab Map tools tab and choose the appropriate ellipsoid. There you can also define a rubberband color and your preferred measurement units (meters or feet) and angle units (degrees, radians and gon). The tools then allows you to click points on the map. Each segment-length as well as the total shows up in the measure-window. To stop measuring click your right mouse button.

|mActionMeasureArea| Areas can also be measured. In the measure window the accumulated area-size appears. In addition, the measuring tool will snap to the currently selected layer, provided that layer has its snapping tolerance set. (See Section snapping_tolerance). So if you want to measure exactly along a line feature, or around a polygon feature, first set its snapping tolerance, then select the layer. Now, when using the measuring tools, each mouse click (within the tolerance setting) will snap to that layer.

|mActionMeasureAngle| You can also measure angles, selecting Measure Angle tool. The cursor becomes cross-shaped. Click to draw the first segment of the angle you wish to measure, then move the the cursor to draw the desired angle. The measure is displayed in a popup dialog.

Measure tools in action

Select and deselect features

The QGIS toolbar provides several tools to select features in the map canvas. To select one or several features just click on |mActionSelect| and select your tool:

To deselect all selected features click on |mActionDeselectAll|.

Projects

The state of your QGIS session is considered a Project. QGIS works on one project at a time. Settings are either considered as being per-project, or as a default for new projects (see Section gui_options). QGIS can save the state of your workspace into a project file using the menu options File –> |mActionFileSave| Save Project or File |mActionFileSaveAs| Save Project As.

Load saved projects into a QGIS session using File –> |mActionFileOpen| Open Project or File ‣ Open Recent Project.

If you wish to clear your session and start fresh, choose File –> |mActionFileNew| New Project. Either of these menu options will prompt you to save the existing project if changes have been made since it was opened or last saved.

The kinds of information saved in a project file include:

  • Layers added
  • Layer properties, including symbolization
  • Projection for the map view
  • Last viewed extent

The project file is saved in XML format, so it is possible to edit the file outside QGIS if you know what you are doing. The file format was updated several times compared to earlier QGIS versions. Project files from older QGIS versions may not work properly anymore. To be made aware of this, in the tab General tab under Settings ‣ Options you can select:

checkbox Prompt to save project changes when required checkbox Warn when opening a project file saved with an older version of QGIS

In the properties window for the project under nix File ‣ Project Properties or win Settings ‣ Project Properties you set project specific options. These include:

  • In the tab General tab the project title, selection and background color, layer units, precision, and the option to save relative paths to layers can be defined. You can define the layer units (only used when CRS transformation is disabled) and the precision of decimal places to use.
  • The tab CRS Coordinate Reference System tab enables you to choose the CRS for this project, and to enable on-the-fly re-projection of raster and vector layers when displaying layers from a different CRS.
  • With the third tab Identifiable layers tab you set (or disable) which layers will respond to the identify tool. (See the Map tools paragraph from the gui_options section to enable identifying of multiple layers.)
  • The tab tab WMS Server allows to define information about the QGIS mapserver Service Capabilities, the Extent and the CRS Restrictions. Activating the checkbox Add WKT geometry to feature info response will allow to query the WMS layers.

Output

There are several ways to generate output from your QGIS session. We have discussed one already in Section ref{sec:projects}: saving as a project file. Here is a sampling of other ways to produce output files:

  • Menu option |mActionSaveMapAsImage| Save as Image opens a file dialog where you select the name, path and type of image (PNG or JPG format). A world file with extension PNGW or JPGW saved in the same folder georeferences the image.
  • Menu option |mActionNewComposer| New Print Composer opens a dialog where you can layout and print the current map canvas (see Section label_printcomposer).

GUI Options

|mActionOptions| Some basic options for QGIS can be selected using the : guilabel:Options dialog. Select the menu option Settings –> |mActionOptions| Options. The tabs where you can optimize your options are:

General Tab

  • checkbox Prompt to save project changes when required
  • checkbox Warn when opening a project file saved with an older version of QGIS
  • Change Selection and background Color
  • Change the icon theme (choose between default, classic, gis and newgis)
  • Change icon size between 16, 24 and 32 pixel.
  • Define double click action in legend (choose between ‘open layer properties’ and ‘open ‘) attribute table.
  • checkbox Capitalize layer names in legend
  • checkbox Display classification attribute names in legend
  • checkbox Create raster icons in legend
  • checkbox Hide splash screen at startup
  • checkbox Open identify results in a dock window (QGIS restart required)
  • checkbox Open snapping options in a dock window (QGIS restart required)
  • checkbox Open attribute table in a dock window
  • checkbox Add PostGIS layers with double click and select in extended mode
  • checkbox Add new layers to selected group
  • Attribute table behavior (choose between Show all features (default), Show selected features, show features in current canvas)
  • Define representation for NULL values
  • Add path(s) to search for additional C++ plugin libraries.

Rendering Tab

  • checkbox By default new layers added to the map should be displayed
  • Define number of features to draw before updating the display.
  • checkbox Use render caching where possible to speed up redraws
  • checkbox Make lines appear less jagged at the expense of some drawing performance
  • checkbox Fix problems with incorrectly filled polygons
  • checkbox Use new generation symbology for rendering
  • Add/remove path(s) to search for Scalable Vector Graphics (SVG) symbols

Additionally you can define whether to save the path for svg textures absolute or relative in the tab General tab of the Settings ‣ Project Properties menu.

Map tools Tab

  • The Mode setting determines which layers will be shown by the Identify tool. By switching to Top down or Top down, stop at first instead of Current layer attributes for all identifiable layers (see the Project properties section under: projects to set which layers are identifiable) will be shown with the Identify tool.
  • checkbox Open feature form, if a single feature is identified
  • Define search radius for identifying and displaying map tips as a percentage of the map width
  • Define ellipsoid for distance calculations
  • Define rubberband color for measure tools
  • Define decimal places
  • checkbox Keep base unit
  • radiobuttonon Define preferred measurement units (meters or feet)
  • radiobuttonon Define preferred angle units (Degrees, Radians or Gon)
  • Define Mouse wheel action (Zoom, Zoom and recenter, Zoom to mouse cursor, Nothing)
  • Define Zoom factor for wheel mouse

Overlays Tab

  • Define placement algorithm for labels (choose between central point (standard), chain, popmusic tabu chain, popmusic tabu and popmusic chain)

Digitizing Tab

  • Define Rubberband line color and line width
  • Define default snap mode (to vertex, to segment, to vertex and segment)
  • Define default snapping tolerance in map units or pixel
  • Define search radius for vertex edits in map units or pixel
  • checkboxShow markers only for selected features
  • Define vertex marker style (cross (default), semi transparent circle or none) and vertex marker size.
  • checkbox Reuse last entered attribute values
  • checkbox Suppress attributes pop-up windows after each created feature

CRS Tab

The CRS tab is divided in two areas. The first area allows to define the default CRS for new projects.

  • Select a CRS and always start new projects with this CRS.
  • checkbox Enable on the fly re-projection by default

The second area allows to define the action, when a new layer is created, or when a layer without CRS is loaded.

  • radiobuttonoff Prompt for Coordinate Reference System (CRS)
  • radiobuttonoff Project wide default Coordinate Reference System (CRS) will be used
  • radiobuttonon :guilabel`Global default Coordinate Reference System (CRS) displayed below will be used`

Locale Tab

  • checkbox Overwrite system locale and use defined locale instead
  • Information about active system locale

Network Tab

  • checkbox Use proxy for web access and define host, port, user, and password.

  • Set the Proxy type according to your needs.

    • Default Proxy: Proxy is determined based on the application

      proxy set using

    • Socks5Proxy: Generic proxy for any kind of connection.

      Supports TCP, UDP, binding to a port (incoming connections) and authentication.

    • HttpProxy: Implemented using the “CONNECT” command, supports only outgoing TCP connections; supports authentication.

    • HttpCachingProxy: Implemented using normal HTTP commands, it is useful only in the context of HTTP requests

    • FtpCachingProxy: Implemented using an FTP proxy, it is useful only in the context of FTP requests

  • Define Cache settings (path and size)

  • Define WMS search address, default is http://geopole.org/wms/search?search=\%1\&type=rss

  • Define timeout for network requests in ms - default is 60000

Excluding some URLs can be added to the text box below the proxy-settings (see Figure fig_proxy-settings) by pressing the Add-button. After that double-click into the just created URL-field and enter the URL you would like to exclude from using the proxy. Obviously the button Remove removes the selected entry.

If you need more detailed information about the different proxy-settings, please refer to the manual of the underlying QT-library-documentation at http://doc.trolltech.com/4.5/qnetworkproxy.html#ProxyType-enum.

Tip

Using Proxies

Using proxies can sometimes be tricky. It is useful to ‘trial and error’ the above proxy types and check if they succeed in your case.

You can modify the options according to your needs. Some of the changes may require a restart of QGIS before they will be effective.

  • nix settings are saved in a texfile: $HOME/.config/QuantumGIS/qgis.conf
  • osx you can find your settings in: $HOME/Library/Preferences/org.qgis.qgis.plist
  • win settings are stored in the registry under:
\\HKEY\CURRENT_USER\Software\QuantumGISqgis

Annotation Tools

annotations text annotation|see{annotations}

The |mActionTextAnnotation| text annotation tools in the attribute toolbar provides the possibility to place formatted text in a balloon on the QGIS map canvas. Use the text annotation tool and click into the map canvas.

introduction/img/en/annotation.png

Annotation text dialog nix

Double click on the item opens a dialog with various options. There is the text editor to enter the formatted text and other item settings. E.g. there is the choice of having the item placed on a map position (displayed by a marker symbol) or to have the item on a screen position (not related to the map). The item can be moved by map position (drag the map marker) or by moving only the balloon. The icons are part of gis theme, and are used by default in the other themes too.

The |mActionAnnotation| move annotation tool allows to move the annotation on the map canvas.

Form annotations

Additionally you can also create your own annotation forms. The |mActionFormAnnotation| form annotation tool is useful to display attributes of a vector layer in a customized qt designer form (see Figure fig:custom-annotations). It is similar to the designer forms for the identify tool, but displayed in an annotation item. Also see QGIS blog http://blog.qgis.org/node/143 for more information.

introduction/img/en/custom_annotation.png

Customized qt designer annotation form nix

Note

If you press Ctrl+T while an annotation tool is active (move annotation, text annotation, form annotation), the visibility states of the items are inverted.

Spatial Bookmarks

Spatial Bookmarks allow you to ``bookmark’’ a geographic location and return to it later.

Creating a Bookmark

To create a bookmark:

  1. Zoom or pan to the area of interest.
  2. Select the menu option View ‣ New Bookmark or press Ctrl-B.
  3. Enter a descriptive name for the bookmark (up to 255 characters).
  4. Click |button| OK to add the bookmark or |button| Cancel to exit without adding the bookmark.

Note that you can have multiple bookmarks with the same name.

Working with Bookmarks

To use or manage bookmarks, select the menu option View ‣ Show Bookmarks. The Geospatial Bookmarks dialog allows you to zoom to or delete a bookmark. You can not edit the bookmark name or coordinates.

Zooming to a Bookmark

From the Geospatial Bookmarks dialog, select the desired bookmark by clicking on it, then click |button| Zoom To. You can also zoom to a bookmark by double-clicking on it.

Deleting a Bookmark

To delete a bookmark from the Geospatial Bookmarks dialog, click on it then click Delete. Confirm your choice by clicking Yes or cancel the delete by clicking No.

Live GPS tracking

To activate Live GPS tracking in QGIS you need to select View ‣ Live GPS tracking. You will get a new docked Window on the left side of the canvas.

There are 4 possible screens in this GPS tracking window (see Figure fig:gpstrack_liv) and Figure fig:gpstrack_options).

With a plugged in GPS receiver (has to be supported by your operating system) a simple click on |button| Connect connects the GPS to QGIS. A second click (now |button| Disconnect) disconnects the GPS-Receiver from your Computer. For GNU/Linux gpsd support is integrated to support connection to most GPS receivers. Therefore you first have to configure gpsd properly to connect QGIS to it.

Warning

If you want to record your position to the canvas you have to create a new vector layer first and switch it to editable status to be able to record your track.

Position coordinates

|mActionToggleEditing| If the GPS is receiving signals from satellites you will see your position in latitude, longitude and elevation as you can see in Figure subfig:gpstrack_main.

GPS signal strength

|gpstrack_barchart| Here you can see the signal strenght of the satellites you are receiving signals from Figure subfig:gpstrack_stren.

GPS polar window

|gpstrack_polarchart| If you want to know where in the sky all the connected satellites are, you have to switch to the polar screen (Figure subfig:gpstrack_polar). You can also see the ID numbers of the satellites you are receiving signals from.

GPS options

|mActionOptions| In case of connection problems you can switch from radiobuttonon Autodetect to radiobuttonon Use path/port below and select the path/port your GPS receiver is connected to. A click on |button| Connect again initiates the connection to the GPS receiver.

With the slider slider GPS Cursor Size you can shrink and grow the position cursor on the canvas. Activating radiobuttonon Auto-add vertices within GPS digitizing your track will automatically be recorded in the active vector layer (of course the layer has to be in edit mode).

With GPS map recenter you can decide in which way the canvas will be updated if your recorded coordinates start either to move out of canvas or there is any change at all.

Track color and width sets the color of and the width of your drawn track.

If you want to set a feature manually you have to go back to |mActionToggleEditing| ‘’Position Coordinates’’ and click on |button| Add feature.

[1]Keyboard shortcuts can now be configured manually (shortcuts presented in this section are the defaults), using the Configure Shortcuts tool under Settings Menu.
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