Hello, Michael,
On 2018-10-24 8:42 a.m., Michael Ossipoff wrote:
The Shadow-Tip method [has] accuracy is greater at lower latitudes.
That's putting it mildly, I think. The method would be OK everywhere
around midday or near an equinox but I suspect it's really, really bad
if used early or late on a midsummer day at higher latitudes. I'm from
55N, and for that latitude I reckon it could reach as much as 45 degrees
off outside of the midday period in summer.
I've nearly always gotten very good results with [the Altitude
Watch method], though there are combinations of time-of-year
and time-of-day when it loses accuracy. Midsummer and roughly
mid afternoon or morning.
Maybe I've misunderstood, the method but I don't understand why
mid-afternoon and mid-morning are the bad times of day. Why is that? I
would expect it to be around noon, when the sun's azimuth can change
significantly for relatively little change in altitude.
Anyway, your method reminded me of another altitude method - a
Shepard's Dial marked out as a solar compass. I once made one and it
worked pretty well, with a bit of degradation around noon. A Mr.
Singleton was the first person I know of to publish the idea.
Steve
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