Hello. I've seen quite a few people ploting their track gradients using the Lidar landscape and the "Snap to World" feature however I feel like the results are noisy and would like to show a more accurate way using QGIS. For this tutorial, you will need to enable the "Profile Tool" plugin in QGIS so go to "Plugins > Manage and Install Plugins" and install it from the repository. First things first, we will need to create a line for the section we are intersted in. In the top toolbar, press the "Create Temporary Scratch Layer" button. Then set the Geometry Type to LineString and Type to Geometry. Once the layer is created, select it and press the "Add Line Feature". If the tool is greyed out, you might have to toggle editing first. Now draw a nice line that stays in between the tracks or at least within the width of the embankment. When you are done, exit the tool with right-click. You can of course save the line in case you had to restart QGIS or whatever. Now for the elevation part. Press the "Elevation Profile" button in the top toolbar to open the tool. Then add your LIDAR map under layers, set the Selection to "Selected Layer" and select the layer with the line that you've created. When that's done, an elevation graph should appear. You can also zoom the graph in and out with the mouse wheel and read the precise elevation data using the cursor. What you should look for at this stage is these long sections with an even rate of elevation change. Excluding small noise or trying to figure out why it makes sense for these short gradients to actually be there in the real world. Then note all the places where the gradient changes happen (I roughly highlighted these for you with blue lines) alongside with their elevation. Also notice that the gradient changes are smoothed out in the real world so try to guess where the middle of the arc is and what the elevation would be if it wasn't there. That should give you pretty good data for plotting tracks in the TSW editor. For example using my Gradient Plotting mini-tutorial.
