This multi-hop playground is best viewed on a laptop or a desktop. Use a mouse roller to zoom and to grab/drag point C. You will need to do some experimenting to get accustomed to how the drawings behave for dragging and scrolling. In one position usining the scroll wheel will move the image up and down. in another context it manages the zoom. When you scroll the image downward, you are also zooming it, so the result may be a small image below the lower border of the view. Just scroll upward and drag the image around as needed. The program has a maximum of six hops that can be added to the chart. With six hops showing, use the tilt-left button to tilt/rotate the diagram to show all hops. It is possible to delete the last hop, but if that happens, just add another hop and you are good to go again. As you add hops, you may also want to tilt to the left so you can see them all.
I suggest you get your first hop in place and then press the recenter button titled "Center on B (Hop1)" to establish the image. Then, you can move around and add hops and play with angles and heights of refraction.
Regions of the ionosphere are shown in light green lines. From lowest to highest, they are D, E, F, F2 and top at 250 miles. You can scroll the pointer to 450 miles, but that becomes meaningless as an estimator of angle and distance because it is unlikely to have a refracted signal above 250 miles.
Totals for path length and time of flight are summarized below the drawing area.
In multi-hop propagation, each corner either on the high end or the low end can result in a 6db to 10db loss. By adding all the corners, you can get an estimate of total loss for the complete path. I have not yet added that calculation to the totals section, because there are other variables that need to be accounted for, and I haven't added those to the model.