Diese Nachricht wurde eingewickelt um DMARC-kompatibel zu sein. Die
eigentliche Nachricht steht dadurch in einem Anhang.

This message was wrapped to be DMARC compliant. The actual message
text is therefore in an attachment.
--- Begin Message ---
Thank you for reworking your equations for me. I have to confess that I'm weak 
at math and matrices make me a little queasy. The spherical trigonometry of 
Morrison's solution is territory I feel safer exploring, once I get my 
quadrants under control.

> On Jul 20, 2024, at 5:44 PM, Steve Lelievre <steve.lelievre.can...@gmail.com> 
> wrote:
> 
> John,
> 
> Here's my second attempt.
> 
> Steve
> 
> >>>>>>
> 
> 
> 
> Sun position vector S is   where ω is hour angle, φ is latitude, and δ is 
> solar declination.
> 
> Azimuth (from south) obeys  so 
> Dividing right hand side by –cos δ and then rearranging  
> 

> Setting a = , b = 1, c =  gives
> 
> a cos ω – b sin ω = c
> 
> Use trig identity 
> 
> a cos ω – b sin ω ≡ R cos(ω + x) where R =  and 
> which converts our case to
> 
> R cos(ω + x) = c
> 
> which rearranges as
> 
> ω =  
> 
> or
> 
> ω = 
>  
> 
> To force correct quadrant
> 
> if γ > 90, use ω =360 − Term 1 – Term 2
> 
> if γ < −90, use ω = −Term 1 – Term 2
> 
> if γ = 0, use ω = 0
> 
> 
> 
> These rules are for latitudes north of Tropic of Cancer. I'll leave you to 
> figure out quadrant adjustments for other cases if you need them. 
> 
> 
> 
> 
> 
> 
> On 2024-07-20 9:13 a.m., John Goodman wrote:
>> No rush; thank you. I appreciate you applying your brain to my concerns!
>> 
>>> On Jul 20, 2024, at 12:11 PM, Steve Lelievre 
>>> <steve.lelievre.can...@gmail.com> <mailto:steve.lelievre.can...@gmail.com> 
>>> wrote:
>>> Oh, no! I think I may have my initial term for tan gamma inverted, so my 
>>> result would be an angle relative to EW.
>>> 
>>> I have to go out for the day now, but will check my calculation when I get 
>>> home.
>>> 
>>> Steve
>>> 


--- End Message ---
---------------------------------------------------
https://lists.uni-koeln.de/mailman/listinfo/sundial

Reply via email to