It is used and I guess it works largely the same way as in author’s first picture: you get arrows pointing towards where you should correct your course to. Tom

It is used and I guess it works largely the same way as in author’s first picture: you get arrows pointing towards where you should correct your course to. Tom Scott has made a video on those: https://wew.youtube.com/watch?v=d99_h30swtM https://wew.youtube.com/watch?v=d99_h30swtM