Gliders can be launched by towrope , best by another aircraft with strong engines , but it has been done with Jeeps , trucks , boats and winches.
To use a winch you have to have a powerfull and fast winch, and a very long towrope.
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All these are methods that CAN be used, but look at the video: there seems to be nothing connected to the tow rope.
\I suppose it is a much thinner line attached to it and to a plane, but too thin or light in color to see.