+<section><title>Layers</title>
+
+<para>
+Layers supported by &appname; are:
+</para>
+<itemizedlist>
+<listitem><para><xref linkend="Aggregate"/></para></listitem>
+<listitem><para><xref linkend="TrackWaypoint"/></para></listitem>
+<listitem><para><xref linkend="GPS"/></para></listitem>
+<listitem><para><xref linkend="DEM"/></para></listitem>
+<listitem><para><xref linkend="Coordinate"/></para></listitem>
+<listitem><para><xref linkend="Maps"/></para></listitem>
+<listitem><para><xref linkend="GeoRef"/></para></listitem>
+</itemizedlist>
+<para>
+For each layer there are a few standard options:
+</para>
+<itemizedlist>
+<listitem><para>Properties - Layer setup / configuration settings</para></listitem>
+<listitem><para>Cut</para></listitem>
+<listitem><para>Copy</para></listitem>
+<listitem><para>Paste</para></listitem>
+<listitem><para>Delete</para></listitem>
+<listitem><para>Visibility - This checkbox on the Layers Panel controls whether the layer is shown in the viewport or not</para></listitem>
+</itemizedlist>
+<para>
+The cut/copy/paste options can be accessed in a variety of ways once the layer has been selected:
+</para>
+<itemizedlist>
+<listitem><para>Standard keys: <keycap>Ctrl+x|c|v</keycap></para></listitem>
+<listitem><para>Main menu <guimenuitem>Edit</guimenuitem></para></listitem>
+<listitem><para>From the right click menu</para></listitem>
+<listitem><para>Buttons at the bottom of the Layers Panel</para></listitem>
+</itemizedlist>
+<para>
+Default values used for each layer's properties can be altered via the <menuchoice><guimenu>Edit</guimenu><guisubmenu>Layer Defaults</guisubmenu></menuchoice> menu options.
+</para>
+<para>
+See the individual section for detail about each layer.
+</para>
+</section>
+
+<section id="TrackWaypoint" xreflabel="TrackWaypoint"><title>TrackWaypoint Layer</title>
+<para>
+TrackWaypoint layers display GPS data (tracks, routes and waypoints).
+</para>
+<para>One way to create new waypoints is to copy a
+latitude/longitude coordinate pair, such as the one shown on most
+geocaches, and paste it into an active TrackWaypoint layer. &appname; can
+automatically recognize several variations of the lat/lon format.
+</para>
+<para>
+By right-clicking on tracks, routes or waypoints in the <xref linkend="gc_layers_panel"/>, you can access many commands on them.
+You can easily find a specific track, route or waypoint by expanding the appropriate containing Tracks, Routes or Waypoints sublayer in the
+layers panel to show all the individual items and then typing the name of the track, route or waypoint.
+</para>
+
+<para>
+The containing Tracks, Routes or Waypoints sublayers are only shown when items of that type exist.
+To start creating them enter into a create mode via either the <guibutton>Create</guibutton> toolbar commands or the <guimenuitem>New</guimenuitem> menu commands.
+</para>
+
+<para>
+The sublayers also offer right click menu options.
+These are the same as those available at the TrackWaypoint level, but only those that relate to the sublayer type.
+</para>
+
+<para>
+By default routes are coloured red. Tracks are automatically assigned a spread of colours.
+</para>
+
+<para>
+Most operations available on tracks are available on routes, except for functionality that relies on having timestamps - since routes by definition have no timing information. Thus for example, uploading a route to OpenStreetMap Traces is not available nor is Geotagging on a route.
+It is possible to convert between Tracks and Routes, although converting from a Track to a Route may involve a loss of information (hence you are required to confirm this operation before it happens).
+</para>
+
+<section><title>Layer Operations</title>
+<para>
+The layer has a context menu with several operations.
+</para>
+
+<section><title>View Layer</title>
+<para>
+Version1.1+: This will automatically move the viewport and select the best zoom level to see the whole layer (i.e. all tracks, routes and waypoints).
+</para>
+</section>
+
+<section><title>View</title>
+
+<section id="track_view_all"><title>View All Tracks</title>
+<para>
+Version1.1+: This will automatically move the viewport and select the best zoom level to see the all the tracks in the layer (ignoring positions of any routes or waypoints).
+</para>
+</section>
+
+<section id="route_view_all"><title>View All Routes</title>
+<para>
+Version1.4+: This will automatically move the viewport and select the best zoom level to see the all the routes in the layer (ignoring positions of any tracks or waypoints).
+</para>
+</section>
+
+<section id="wp_view_all"><title>View All Waypoints</title>
+<para>
+Version1.1+: This will automatically move the viewport and select the best zoom level to see the all the waypoints in the layer (ignoring positions of any tracks or routes).
+</para>
+</section>
+
+</section>
+
+<section><title>Goto Center of Layer</title>
+<para>
+This will automatically move the viewport to see the whole layer (i.e. tracks, routes and waypoints). It does not adjust the zoom level.
+</para>
+</section>
+
+<section id="wp_goto"><title>Goto Waypoint</title>
+<para>
+This opens a dialog box to enter a name of waypoint to search for. If it is found the viewport is centred on it.
+</para>
+<note>
+<para>
+Note this search is not very clever and only finds exact matches.
+You are probably better off expanding the waypoint list and directly start typing, as mentioned above, which finds a match based on each letter typed.
+</para>
+</note>
+</section>
+
+<section><title>Export Layer</title>
+<para>
+The layer (all tracks, routes and waypoints) can be exported to a file GPX, GPSPoint, GPSMapper or Google's KML format.
+</para>
+<para>
+Version1.1+: An individual track can be exported to a GPX file via the track menu.
+</para>
+</section>
+
+<section id="finish_track"><title>Finish Track or Route</title>
+<para>
+Selecting this option ends the creation of that individual track or route.
+</para>
+<note>
+<para>
+This is only available when a track or route is being created by the <xref linkend="track_create"/> or <xref linkend="route_create"/> tools.
+</para>
+</note>
+</section>
+
+<section><title>New</title>
+<section id="new_wp"><title>New Waypoint</title>
+<para>
+This opens a dialog box to create a new waypoint. A default name will be suggested and the default position is the center of the viewport.
+</para>
+</section>
+<section id="new_track"><title>New Track</title>
+<para>
+This turns on the <xref linkend="track_create"/> tool.
+</para>
+</section>
+<section id="new_route"><title>New Route</title>
+<para>
+This turns on the <xref linkend="route_create"/> tool.
+</para>
+</section>
+</section>
+
+<section><title>Geotag Images</title>
+<para>
+This starts the Geotagging Images dialog against all tracks in the layer.
+See <link linkend="geotagging">Geotagging</link> for further detail.
+</para>
+</section>
+
+<section><title>Acquire</title>
+<para>
+This offers the same choice from <xref linkend="acquire"/> methods as on the <guimenu>File</guimenu> menu.
+However when invoked from here, the results will be stored in this layer (instead of creating a new one).
+</para>
+</section>
+
+<section><title>Upload</title>
+
+<section id="gps_upload"><title>Upload to GPS</title>
+<para>
+This opens a dialog to select the GPS Device and port to which the layer information will be transferred.
+</para>
+<para>
+The types of GPS information (tracks, routes or waypoints) to be transferred can be selected.
+</para>
+<para>
+Tracks, Routes or Waypoints that are invisible will not be transferred.
+</para>
+</section>
+
+<section id="osm_upload" xreflabel="Upload To OSM" ><title>Upload To OSM</title>
+<para>
+This opens a dialog to upload all tracks and waypoints to <ulink url="http://openstreetmap.org/">OpenStreetMap</ulink> traces.
+Useful if you are an OpenStreetMap contributor (you will need an OpenStreetMap account), these details can be stored in &appname; <xref linkend="prefs_osm"/>
+</para>
+<para>
+ &appname; allows you to edit a track, e.g. remove duplicate points, perhaps remove track points leading to your home and then upload it to OpenStreetMap.
+</para>
+<warning>
+<para>
+The password is transferred <emphasis role="bold">unencrypted</emphasis> in every request sent to the OpenStreetMap server. This is due to the use of OpenStreetMap's basic authentication method.
+</para>
+<para>Currently &appname; does not support the <ulink url="http://oauth.net/">OAuth</ulink> mechanism.</para>
+</warning>
+</section>
+
+</section>
+
+<section><title>Delete</title>
+<para>Offers deletion of various parts of a TrackWaypoint layer:</para>
+<section id="delete_all_tracks"><title>Delete All Tracks</title>
+<para>Deletes all the tracks in this layer.</para>
+</section>
+<section id="delete_selection_tracks"><title>Delete Tracks from Selection</title>
+<para>Opens a dialog with list of all the tracks from this layer to choose the ones to delete.</para>
+</section>
+<section id="delete_all_routes"><title>Delete All Routes</title>
+<para>Deletes all the routes in this layer.</para>
+</section>
+<section id="delete_selection_routes"><title>Delete Routes from Selection</title>
+<para>Opens a dialog with list of all the routes from this layer to choose the ones to delete.</para>
+</section>
+<section id="delete_all_waypoints"><title>Delete All Waypoints</title>
+<para>Deletes all the waypoints in this layer.</para>
+</section>
+<section id="delete_selection_waypoints"><title>Delete Waypoints from Selection</title>
+<para>Opens a dialog with list of all the waypoints from this layer to choose the ones to delete.</para>
+</section>
+</section>
+
+<section><title>Filter</title>
+<section><title>Simplify All Tracks</title>
+<para>
+This opens dialog to request the number of points each track will be simplified using <application>GPSBabel</application>. The result is put into a new layer. The simplification method removes points considered to be in a 'near straight line', thus reducing the number of points and attempting to keep the most important turning points.
+</para>
+</section>
+<section><title>Remove Duplicate Waypoints</title>
+<para>
+Remove Duplicate Waypoints - fairly self explainatory, with the results created in a new layer.
+</para>
+<note>
+<para>
+However it only considers a precise position (waypoints only 1 metre away from each other are considered different) and also doesn't consider if the waypoints have different comments, symbols or images.
+</para>
+</note>
+</section>
+</section>
+
+<section id="filter_with_track"><title>Filter With <emphasis>Trackname</emphasis></title>
+<para>
+This runs <application>GPSBabel</application> on the layer using information from a previously selected track (select via the track menu "Use With Filter" option) with the following command types:
+</para>
+<itemizedlist>
+<listitem><para>Waypoints Inside This</para></listitem>
+<listitem><para>Waypoints Outside This</para></listitem>
+</itemizedlist>
+<para>
+The result is generated in a new Track/Waypoint layer.
+</para>
+</section>
+
+<section><title>Geotag Images</title>
+<para>
+This starts the Geotagging Images dialog using the specific track.
+See <link linkend="geotagging">Geotagging</link> for further detail.
+</para>
+</section>
+
+</section><!-- End TRW Layer Options -->
+
+<section><title>Track and Route Sublayer Options</title>
+<para>Repeats options available at the TrackWaypoint level, but only those for tracks and routes:</para>
+<itemizedlist>
+<listitem><para>Finish Track or Route. Same as the layer <link linkend="finish_track">Finish Track or Route</link></para></listitem>
+<listitem><para>New Track or Route. Same as the layer <link linkend="new_track">New Track</link> or <link linkend="new_route">New Route</link></para></listitem>
+<listitem><para>View All Tracks or Routes. Same as the layer <link linkend="track_view_all">View All Tracks</link> or <link linkend="route_view_all">View All Routes</link></para></listitem>
+<listitem><para>Delete All Tracks or Routes. Same as the layer <link linkend="delete_all_tracks">Delete All Tracks</link> or <link linkend="delete_all_routes">Delete All Routes</link></para></listitem>
+<listitem><para>Delete Tracks or Routes from Selection. Same as the layer <link linkend="delete_selection_tracks">Delete Tracks from Selection</link> or <link linkend="delete_selection_routes">Delete Routes from Selection</link></para></listitem>
+</itemizedlist>
+</section>
+
+<section><title>Track and Route Properties</title>
+<para>
+Show many useful statistics about a track or a route, including a
+elevation-distance graph and a speed-time graph (if data is available).
+You can click these graphs to jump to the point in the track. You can
+also reverse it, delete duplicates, and split a track from its
+component segments (discontinuous breaks in a track) into separate
+tracks.
+</para>
+<para>
+The following colors are used in the elevation-distance graph:
+</para>
+<variablelist>
+<varlistentry>
+<term><emphasis>Main</emphasis> colour - this is dependent on your Desktop theme - often blue by default</term>
+<listitem><para>elevation data in graph</para></listitem>
+</varlistentry>
+<varlistentry>
+<term>Yellow</term>
+<listitem>
+<para>no elevation data</para>
+</listitem>
+</varlistentry>
+<varlistentry>
+<term>Green</term>
+<listitem>
+<para>elevation data from DEM</para>
+</listitem>
+</varlistentry>
+<varlistentry>
+<term>Red</term>
+<listitem>
+<para>speed</para>
+</listitem>
+</varlistentry>
+</variablelist>
+
+</section>
+
+<section><title>Track and Route Operations</title>
+
+<section><title>Finish Track</title>
+<para>
+Selecting this option ends the creation of the individual track.
+</para>
+<note>
+<para>
+This is only available when a track is being created by the <xref linkend="track_create"/> tool.
+</para>
+</note>
+</section>
+
+<section><title>Goto</title>
+<para>
+This centers the viewport on the selected position on the track:
+</para>
+<itemizedlist>
+<listitem><para>Startpoint</para></listitem>
+<listitem><para>"Center" - the notional center from the bounds of the track</para></listitem>
+<listitem><para>Endpoint</para></listitem>
+<listitem><para>Version1.1+: Highest Altitude</para></listitem>
+<listitem><para>Version1.1+: Lowest Altitude</para></listitem>
+<listitem><para>Version1.1+: Maximum Speed (Not Available on Routes)</para></listitem>
+</itemizedlist>
+</section>
+
+<section><title>View</title>
+<para>
+Version1.1+: This centers the viewport on the track and selects the best zoom level to see it.
+</para>
+</section>
+
+<section><title>Combine</title>
+<section><title>Merge By Time</title>
+<para>
+This operation repeatedly tries to merge the right-clicked track
+with tracks in the same TrackWaypoint layer. The tracks which are
+merged are those which have at least one trackpoint less than some
+threshold time away. This way, if you somehow end up with lots of small
+segments (say, caused by turning the GPS on and off) you can merge them
+easily into one track.
+</para>
+<note>
+<para>
+This is not available on routes as they have no timestamps.
+</para>
+</note>
+</section>
+
+<section><title>Merge With Other Tracks</title>
+<para>
+This opens a dialog listing the other tracks in the same TrackWaypoint layer, from which one can select the other tracks to merge with.
+</para>
+</section>
+
+<section><title>Merge Segments</title>
+<para>
+Combines track segments. Effectively removing track segment markers to leave one segment for the whole track.
+</para>
+</section>
+
+<section><title>Append Track or Route</title>
+<para>
+Enable joining of a single track to the end of the current track.
+This opens a dialog listing the other tracks in the same TrackWaypoint layer from which one can make the selection.
+</para>
+</section>
+</section>
+
+<section><title>Split</title>
+<section><title>Split By Time</title>
+<para>
+This operation will split a single track into segments wherever the
+time interval between successive trackpoints is larger than some
+threshold. This is useful when processing raw NMEA GPS data, especially
+taken over a long time.
+</para>
+<note>
+<para>
+This is not available on routes as they have no timestamps.
+</para>
+</note>
+</section>
+
+<section><title>Split By Number of Points</title>
+<para>
+Version1.2+: This operation will split a single track into segments by the number of points specified.
+This can be useful with devices which may have limits on the number of points it supports.
+</para>
+</section>
+
+<section><title>Split Segments</title>
+<para>
+Splits track segments into new tracks.
+</para>
+<note>
+<para>
+This is not available on routes as they do not have route segments.
+</para>
+</note>
+</section>
+
+<section><title>Split at Trackpoint</title>
+<para>
+Splits the track at the currently selected trackpoint.
+</para>
+<note>
+<para>
+This is only enabled when a trackpoint is selected.
+</para>
+</note>
+</section>
+</section>
+
+<section><title>Delete Points</title>
+<section><title>Delete Points With the Same Position</title>
+<para>
+Deletes subsequent points that have the same position (but have different timestamps).
+</para>
+</section>
+<section><title>Delete Points With the Same Time</title>
+<para>
+Deletes subsequent points that have the same time stamp (but may have different positions).
+</para>
+<note>
+<para>
+This is not available on routes as they have no timestamps.
+</para>
+</note>
+</section>
+
+</section>
+
+<section><title>Apply DEM data</title>
+<para>
+If any DEM data is loaded, this will apply the DEM data to give the track elevation data.
+</para>
+</section>
+
+<section><title>Export Track as GPX</title>
+<para>
+Version1.1+: This allows exporting the track as a GPX file by opening a file save dialog.
+</para>
+</section>
+
+<section><title>Extend Track End</title>
+<para>
+Changes the current tool to add trackpoints to the end of the track.
+</para>
+</section>
+
+<section><title>Extend Using Route Finder</title>
+<para>
+Enables the Route Finder tool. Thus on a subsequent left click in the viewport, a route is calculated from the end of track to that point using the default route service and applied to the track.
+</para>
+</section>
+
+<section><title>Upload</title>
+
+<section><title>Upload to GPS</title>
+<para>
+Same as the layer <link linkend="gps_upload">Upload to GPS</link> command, but only applies to the track.
+</para>
+</section>
+
+<section><title>Upload to OSM</title>
+<para>
+Same as the layer <link linkend="osm_upload">Upload to OSM</link> command, but only applies to the track.
+</para>
+</section>
+
+</section>
+
+<section><title>Use With Filter</title>
+<para>
+This selects the track to be used in the <link linkend="filter_with_track">Filter With <emphasis>Trackname</emphasis></link> feature.
+</para>
+<note>
+<para>
+This is not available on routes.
+</para>
+</note>
+</section>
+
+<section><title>Refine Route...</title>
+<para>
+This function allows to request a Routing Engine in order to refine a given route.
+By "refining" we mean computing all real intermediates points between some given major points.
+This could be useful to compute a trip giving only the wished important steps.
+</para>
+<note>
+<para>
+This is only available on routes.
+</para>
+</note>
+</section>
+
+<section><title>View Google Directions</title>
+<para>
+This option is only available on a track created using the Route Finder tool.
+</para>
+<para>
+Launch a web browser to see the Google directions page which yielded the route.
+</para>
+<note>
+<para>
+The record of the Google route is stored in the track's comment, so if the comment is changed (or the route was created by something other than the Route Finder tool) this will not work correctly.
+</para>
+</note>
+</section>
+
+</section><!-- End Track Options -->
+
+<section><title>Waypoint Sublayer Options</title>
+<para>Repeats options available at the TrackWaypoint level, but only those for waypoints:</para>
+<itemizedlist>
+<listitem><para>New Waypoint. Same as the layer <link linkend="new_wp">New Waypoint</link></para></listitem>
+<listitem><para>View All Waypoints. Same as the layer <link linkend="wp_view_all">View All Waypoints</link></para></listitem>
+<listitem><para>Goto Waypoint. Same as the layer <link linkend="wp_goto">Goto Waypoint</link></para></listitem>
+<listitem><para>Delete All Waypoints. Same as the layer <link linkend="delete_all_waypoints">Delete All Waypoints</link></para></listitem>
+<listitem><para>Delete Waypoints from Selection. Same as the layer <link linkend="delete_selection_waypoints">Delete Waypoints from Selection</link></para></listitem>
+</itemizedlist>
+</section>
+
+<section><title>Waypoint Properties</title>
+
+<para>
+This shows a dialog with detailed information for the waypoint. Many properties of the waypoint can changed here, such as the comment, the symbol used in drawing or the image (normally a photograph taken at this position) assiocated with it. When a waypoint has an image, a thumbnail of it is drawn in the viewport for the waypoint (in preference to the symbol).
+</para>
+<para>
+If the waypoint has an associated image, then the Geotag information may be updated, either with updating the file's modification timestamp or not.
+This can be useful when the waypoint has been moved.
+</para>
+
+</section><!-- WP Prop END -->
+
+<section><title>Waypoint Operations</title>
+
+<section><title>Goto</title>
+<para>
+This centers the viewport on the selected waypoint.
+</para>
+</section>
+
+<section><title>Visit Webpage</title>
+<para>
+If the waypoint's comment (or description) starts with <literal>http:</literal> then this option is available and allows launching a web browser to go to the webpage.
+</para>
+</section>
+
+<section><title>Visit Geocache Webpage</title>
+<para>
+If the waypoint's name is in Geocache form (GCXXXXX) then this option is available and allows launching a web browser to go to the Geocache page.
+</para>
+</section>
+
+<section><title>New Waypoint</title>
+<para>
+Same as the layer <link linkend="new_wp">New Waypoint</link>.
+</para>
+</section>
+
+</section><!-- WP END -->
+
+<section id="geotagging" xreflabel="Geotagging"><title>Version1.3+: Geotag Images</title>
+<para>
+This dialog allows geotagging images (normally taken with a digital camera) via interpolation against a specific track or all tracks in the TrackWaypoint layer - depending on how it is invoked.
+</para>
+<para>
+Images need to have an EXIF DATE_TIME_ORIGINAL (nearly always set by a camera). This timestamp is then used to find the location when the image(s) was taken by searching through the track(s) to find the nearest time - interpolating between points if necessary to set the location.
+</para>
+<note>
+<para>
+Generally it is good policy to synchronize your camera's clock with your GPS clock before taking photographs. However the times can be adjusted afterwards (if necessary) to take into consideration clock differences.
+</para>
+</note>
+<para>
+Various options allow control of how the geotagging process is performed:
+</para>
+<itemizedlist>
+<listitem><para>Images - Add the images used for geotagging</para></listitem>
+<listitem><para>Create Waypoints</para></listitem>
+<listitem><para>Overwrite Existing Waypoints</para></listitem>
+<listitem><para>Write EXIF</para></listitem>
+<listitem><para>Overwrite Existing GPS Information</para></listitem>
+<listitem><para>Interpolate Between Track Segments</para></listitem>
+<listitem><para>Image Time Offset - The number of seconds to ADD to the photos time to make it match the GPS data. Calculate this with (GPS - Photo). Can be negative or positive. Useful to adjust times when a camera's timestamp was incorrect.</para></listitem>
+<listitem><para>Image Timezone - The timezone that the used when the images were created. For example, if a camera is set to AWST or +8:00 hours. Enter +8:00 here so that the correct adjustment to the images' time can be made. GPS data is always in UTC.</para></listitem>
+</itemizedlist>
+</section>
+
+</section><!-- TRW Layer END -->
+
+<section id="GPS" xreflabel="GPS"><title>GPS Layer</title>
+<para>
+The GPS layer is responsible for uploading and downloading GPS data
+from a GPS device. It also is responsible for realtime GPS tracking.
+Expand the GPS layer in the layers panel to see the two <xref linkend="TrackWaypoint"/> layers it
+uses for uploading and downloading. To upload, download, or use
+realtime tracking, right-click the GPS layer and click the appropiate
+menu item.
+</para>
+
+<section><title>Download</title>
+<para>
+To download data from the GPS, right-click the GPS layer and click <guimenuitem>Download from GPS</guimenuitem>.
+</para>
+</section>
+
+<section><title>Upload</title>
+<para>
+To upload data to the GPS, first populate the GPS Upload child
+layer of the GPS layer (either by creating waypoints/tracks/routes in it, or
+copying and pasting or dragging waypoints/tracks/routes from another layer).
+Then right-click the GPS layer and click <guimenuitem>Upload to GPS</guimenuitem>.
+</para>
+</section>
+
+<section><title>Realtime Tracking</title>
+<para>
+You must set up gpsd correctly or use a GPSD server and put the
+correct information in the GPS layer properties dialog. Then right-click
+the layer and select <guimenuitem>Start Realtime Tracking</guimenuitem>.
+</para>
+</section>
+
+<section><title>Empty <emphasis>Item</emphasis></title>
+<para>
+There are several options to quickly delete a subsection of data:
+</para>
+<itemizedlist>
+<listitem><para>Empty Realtime</para></listitem>
+<listitem><para>Empty Upload</para></listitem>
+<listitem><para>Empty Download</para></listitem>
+<listitem><para>Empty All</para></listitem>
+</itemizedlist>
+</section>
+
+</section><!-- End GPS -->
+
+<section id="DEM" xreflabel="DEM"><title>DEM (Digital Elevation Model) Layer</title>
+<para>
+This layer provides elevation data from the <ulink url="http://www2.jpl.nasa.gov/srtm/">Shuttle Radar Topography Mission (SRTM)</ulink>
+</para>
+<para>
+Elevation data can be useful in planning trips, as you many wish to avoid/minimise the hills encountered. [OSM Cyclemap is also useful this way too]
+</para>
+<para>
+To download the data use the DEM Download tool (shown on the toolbar), and then click on a area of the viewport. Once files have been downloaded they can then be loaded from disk via the DEM properties in future application runs.
+</para>
+<para>
+The current data server is: <ulink url="http://dds.cr.usgs.gov/srtm/version2_1/">NASA STRM 2.1</ulink>.
+</para>
+<para>
+ATM &appname; does not auto download DEM data. If you want to get lots of data blocks, you may wish to use some other program get such as <application>curl</application> or <application>wget</application> to download them for an area.
+</para>
+<note>
+<para>
+Using many DEMs is CPU/memory intensive. Depending on your computer's capability, &appname; will be less responsive when about 50+ DEM blocks are loaded. It is probably unwise to attempt using 200+ blocks, so trying to use DEMs covering large countries/continents (USA, Australia etc...) is unlikely to work. In these conditions under Linux, &appname; may be automatically stopped by the "<ulink url="http://en.wikipedia.org/wiki/Out_of_memory/">OOM</ulink> Killer"
+</para>
+</note>
+
+</section><!-- End DEM -->
+
+
+<section id="Maps" xreflabel="Maps"><title>Maps Layer</title>
+<para>
+This layer provides a single map resource, you may have multiple map layers but only top one (if enabled) will be visible.
+You will need an open internet connection when you are downloading maps, but once downloaded they are available from the hard disk cache. When map are avaliable from the disk cache it is much faster and can be used offline.
+</para>
+<para>
+Some maps are continually improving over time (e.g. OpenStreetMap) and so in order to not to have to (re)download the data all the time &appname; employs a timeout method - <emphasis>Tile Age</emphasis> to determine whether to access the server. However a forced refresh for the current view can be made via the <guilabel>Reload All Onscreen Maps</guilabel> option.
+</para>
+<para>
+Inbuilt maps include various <ulink url="http://en.wikipedia.org/wiki/TerraServer-USA">Terraserver</ulink> (Primarily USA coverage) and <ulink url="http://openstreetmap.org/">OpenStreetMap (OSM)</ulink> ones and more:
+</para>
+<itemizedlist>
+<listitem><para>Bing Bird's Eye (Aerial) Maps (&appname; Version1.2+)</para></listitem>
+<listitem><para>Terraserver Topos</para></listitem>
+<listitem><para>Terraserver Aerials</para></listitem>
+<listitem><para>Terraserver Urban Areas</para></listitem>
+<listitem><para>OpenStreetMap (Mapquest) - This is the default (&appname; Version1.3+)</para></listitem>
+<listitem><para>OpenStreetMap (Mapnik)</para></listitem>
+<listitem><para>OpenStreetMap (Cycle)</para></listitem>
+<listitem><para>OpenStreetMap (Transport) (&appname; Version1.3+)</para></listitem>
+<listitem><para>NASA BlueMarble</para></listitem>
+<listitem><para>SpotMap (&appname; Version1.1+)</para></listitem>
+</itemizedlist>
+
+<para>
+&appname; can be configured to handle additional maps. See <xref linkend="extend_viking"/> for further detail.
+</para>
+
+<section><title>Layer Operations</title>
+<section><title>Download Missing Onscreen Maps</title>
+<para>
+This requests map tiles for areas of the viewport that do not currently have one.
+</para>
+</section>
+
+<section><title>Download New Onscreen Maps</title>
+<para>
+This requests map tiles only if the maps are older than the Tile Age preference.
+</para>
+</section>
+
+<section><title>Reload All Onscreen Maps</title>
+<para>
+Force a refresh of all visible map tiles.
+</para>
+</section>
+</section>
+
+
+</section><!-- End Maps -->
+
+<section id="Aggregate" xreflabel="Aggregate"><title>Aggregate Layer</title>
+<para>
+This layer is a container layer to hold other layers. There is always an initial and controlling <emphasis>Top Layer</emphasis> that can not be removed or renamed.
+</para>
+<para>
+This layer type is useful for grouping other layers, especially <xref linkend="TrackWaypoint"/> layers, in whatever categories are relevant to you: such as by activity, location or date.
+Here are some suggestions:
+<itemizedlist>
+<listitem><para>Hiking</para></listitem>
+<listitem><para>Mountain Biking</para></listitem>
+<listitem><para>Road Cycling</para></listitem>
+<listitem><para>Car Trips</para></listitem>
+<listitem><para>Sailing</para></listitem>
+<listitem><para>Holidays</para></listitem>
+<listitem><para>UK Points of Interest</para></listitem>
+<listitem><para>USA Points of Interest</para></listitem>
+<listitem><para>etc...</para></listitem>
+</itemizedlist>
+</para>
+<para>
+Thus one can have a list of all your tracks, but groups can be shown or not using the relevant layers visibility checkbox.
+</para>
+
+<para>
+This layer only has one operation: <guilabel>New Layer</guilabel>
+</para>
+
+<section><title>New Layer</title>
+<para>
+Add a new layer of the selected type.
+</para>
+</section>
+
+</section><!-- End Agg -->
+
+<section id="GeoRef" xreflabel="GeoRef"><title>GeoRef Layer</title>
+<para>
+This layer allows one to use any image as a map. You will need to tell it how to align the map to a position in the world and the scale of map.
+</para>
+<section><title>Layer Operations</title>
+<section><title>Zoom to Fit Map</title>
+<para>
+Automatically set a zoom level to see the entire map coverage.
+</para>
+</section>
+
+<section><title>Goto Map Center</title>
+<para>
+Center the viewport on this map.
+</para>
+
+</section>
+<section><title>Export to World File</title>
+<para>
+Opens a file save dialog to save the scale and position information as a <ulink url="http://en.wikipedia.org/wiki/World_file">World File</ulink>.
+</para>
+</section>
+</section>
+
+</section><!-- End GeoRef -->
+
+<section id="Coordinate" xreflabel="Coordinate"><title>Coordinate Layer</title>
+<para>
+This layer is allows drawing of grid lines on the viewport.
+</para>
+</section><!-- End Coord -->
+
+
+<section id="tools" xreflabel="Tools"><title>Tools</title>
+<para>
+&appname;'s mouse actions on the viewport are controlled by which tool is active. Only one tool can be active at a time. The default mode is pan.
+</para>
+<para>
+You can use the scroll wheel, the middle-click, the middle-click+drag to zoom, center map at position and pan respectively no matter what tool you are using.
+</para>
+<para>
+<keycap>Scroll</keycap>: zoom in and out keeping the mouse over same location
+</para>
+<para>
+<keycap>Ctrl-scroll</keycap>: pan north-south (also <keycap>Ctrl-up</keycap>, <keycap>Ctrl-down</keycap>)
+</para>
+<para>
+<keycap>Shift-scroll</keycap>: pan east-west (also <keycap>Ctrl-left</keycap>, <keycap>Ctrl-right</keycap>)
+</para>
+<para>
+<keycap>Ctrl-shift-scroll</keycap>: zoom in and out, without changing the center (also <keycap>Ctrl+</keycap>, <keycap>Ctrl-</keycap> [*not* KeyPad +/-])
+</para>
+<para>
+<keycap>Middle-click</keycap>: make the clicked point on the map the center
+</para>
+<para>
+<keycap>Middle-click</keycap> and drag: pan
+</para>
+
+<section><title>Pan</title>
+<para>
+This is the default mode of operation for &appname;.
+</para>
+<para>
+This mode is entered by clicking on the toolbar icon: <guiicon><inlinegraphic fileref="figures/mover_22.png"/></guiicon>
+</para>
+<para>
+Pan moves the viewpoint. A single click centers the viewport at that point, whereas click and drag dynamically moves the view around.
+This is the default tool.
+</para>
+<para>
+This mode can also be entered by the keyboard shortcut <keycap>Ctrl+Shift+P</keycap>
+</para>
+</section>
+
+<section><title>Zoom</title>
+<para>
+This mode is entered by clicking on the toolbar icon: <guiicon><inlinegraphic fileref="figures/zoom_18.png"/></guiicon>
+</para>
+<para>
+Zooms in and out on the clicked part of the map or by the selected area.
+</para>
+<para>
+This mode can also be entered by the keyboard shortcut <keycap>Ctrl+Shift+Z</keycap>
+</para>
+<para>
+<keycap>Ctrl</keycap> + left or right click: Zoom in/out and center the map on the clicked location
+</para>
+<para>
+<keycap>Shift</keycap> (and hold) + left mouse button: Draws a bounding box area on which to zoom in. The zoom action is performed when the left mouse button is released.
+</para>
+</section>
+
+<section><title>Ruler</title>
+<para>
+This mode is entered by clicking on the toolbar icon: <guiicon><inlinegraphic fileref="figures/ruler_18.png"/></guiicon>
+</para>
+<para>
+The ruler is used to measure the bearing and distance between two points: Click on first point and then move the mouse point around - the values will be continually updated.
+A second click will <emphasis>freeze</emphasis> the ruler at that point.
+</para>
+<para>
+This mode can also be entered by the keyboard shortcut <keycap>Ctrl+Shift+U</keycap>
+</para>
+</section>
+
+<section id="select" xreflabel="Select"><title>Version1.1+: Select</title>
+<para>
+This mode is entered by clicking on the toolbar icon: <guiicon><inlinegraphic fileref="figures/select_18.png"/></guiicon>
+</para>
+<para>
+The select tool allows one to choose any waypoint or track by clicking on it (or reasonably near) in the viewpoint.
+</para>
+<para>
+ATM to select a track one must actually click on a trackpoint, which is also selected.
+</para>
+<para>
+This mode can also be entered by the keyboard shortcut <keycap>Ctrl+Shift+S</keycap>
+</para>
+</section>
+
+<section><title>TrackWaypoint Layer Tools</title>
+<para>
+You must have a <xref linkend="TrackWaypoint"/> Layer selected to use these tools.
+</para>
+<section id="createwptool" xreflabel="Create Waypoint"><title>Create Waypoint</title>
+<para>
+Enable this tool by clicking on the toolbar icon: <guiicon><inlinegraphic fileref="figures/addwp_18.png"/></guiicon>
+</para>
+<para>
+Left click will open the new waypoint dialog using the specified position.
+</para>
+</section>
+
+<section id="track_create" xreflabel="Create Track"><title>Create Track</title>
+<para>
+Enable this tool by clicking on the toolbar icon: <guiicon><inlinegraphic fileref="figures/addtr_18.png"/></guiicon>
+</para>
+<para>
+Left click to create a new trackpoint. If it's the initial trackpoint you will be asked to enter a name for the track.
+If <keycap>Ctrl</keycap> is held at the same time, it will jump the new trackpoint position to a nearby existing trackpoint.
+Right click or <keycap>Backspace</keycap>: undo one point.
+</para>
+<para>
+Double click or <keycap>Escape</keycap>: to finish track creation.
+Finishing the track is also available via the right click <xref linkend="TrackWaypoint"/> and track menus.
+</para>
+<para>
+One must finish the current track to be able to create another track.
+</para>
+</section>
+
+<section id="route_create" xreflabel="Create Route"><title>Create Route</title>
+<para>
+Enable this tool by clicking on the toolbar icon: <guiicon><inlinegraphic fileref="figures/vik_new_route_18.png"/></guiicon>
+</para>
+<para>
+This operates in exactly the same way as the <link linkend="track_create">Create Track</link> above.
+</para>
+<para>
+One must finish the current route to be able to create another route.
+</para>
+</section>
+
+<section><title>Edit Waypoint</title>
+<para>
+Enable this tool by clicking on the toolbar icon: <guiicon><inlinegraphic fileref="figures/edwp_18.png"/></guiicon>
+</para>
+<para>
+Left Click/drag: select/move a waypoint.
+If <keycap>Ctrl</keycap> is held at the same time, it will jump the waypoint position to a nearby existing trackpoint.
+If <keycap>Shift</keycap> is held at the same time, it will jump the waypoint position to a nearby existing waypoint.
+</para>
+<para>Right-click on waypoint: opens a menu with waypoint actions (the
+same menu accessed by right-clicking the waypoint in the layers panel)
+</para>
+</section>
+
+<section><title>Edit Trackpoint</title>
+<para>
+Enable this tool by clicking on the toolbar icon: <guiicon><inlinegraphic fileref="figures/edtr_18.png"/></guiicon>
+</para>