show the curve. your observations that you have studied.
Should be simple.
It will require some personal effort, however.
Shoreline location, tripod, zoom lens camera, spherical trigonometry, reliable map for measuring distance.
spoiler alert:
The results of this test is ALL OVER YouTube. 1000's of videos.
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I feel like I'm asking a dub to watch the ARC testimony of Geoffery Jackson on YouTube.