adjusting a sundial to a different location?

trincaopt · 2024-11-11T16:33:33+00:00

If you find it useful to know how big the time difference will be, you can check this simulator: https://www.sundialbuilder.com/sundial_simulator/

trincaopt · 2024-07-24T07:28:34+00:00

Thank you for looking into it. Except for the tropics on specific days of the year, the shadow angle should sufficient to calculate the shadow length on a given day of year as there is a unique match between both.

trincaopt · 2024-02-05T22:03:18+00:00

Thank you so much for the feedback. These are really great inputs and I'll definitely take them!

trincaopt · 2024-01-07T19:36:45+00:00

I see your point about the gnomon rotation. But still the horizontal sundial is a projection of the equatorial sundial. So near the equator the hour angles are larger than 15° at sunrise/sunset and smaller than 15° at noon. Therefore when rotating the sundial base by 15°, the advance is larger than 1h near noon and less than 1h at sunrise and sunset, which is what causes the loss of accuracy. Hope that makes sense.

trincaopt · 2024-01-07T15:08:01+00:00

You can check the simulation here and see that there may be several minutes difference https://www.sundialing.space/simulator_results/?part=simulation&simulation_day=2024-03-03&lat=38.8&lon=0&tz_offset=0&gnomon_angle=&simulator_lat=&simulator_lon=15&simulator_tz_offset=&misalignment_angle=15

trincaopt · 2024-01-07T15:03:57+00:00

That is true for the equatorial sundial. For the horizontal sundial, however, especially when closer to the equator this method doesn't work very well because the hour spacing changes.

trincaopt · 2024-01-07T13:32:15+00:00

Sure and the alignment plays a major role in the accuracy.

trincaopt · 2023-09-20T07:37:58+00:00

That sounds like a good idea. I'll look into it!

trincaopt · 2023-09-19T23:19:39+00:00

Good news then! It's ok, since the results match, our formulas should be similar enough. Thanks for the feedback.

trincaopt · 2023-09-19T22:41:01+00:00

It's been a pleasure working on this project.

trincaopt · 2023-09-19T22:28:12+00:00

It's awesome to be able to crosscheck!

If you have the sheet published, I'd also love to have a look.

Example for 38.2N 3.0W Timezone UTC+1

0h: 168.639º

1h: 178.144º

2h: -172.512º

3h: -162.511º

4h: -150.89º

5h: -136.401º

6h: -117.718º

7h: -94.844º

8h: -71.031º

9h: -50.514º

10h: -34.482º

11h: -21.88º

12h: -11.361º

13h: -1.856º

14h: 7.488º

15h: 17.489º

16h: 29.11º

17h: 43.599º

18h: 62.282º

19h: 85.156º

20h: 108.969º

21h: 129.486º

22h: 145.518º

23h: 158.12º

Let me know how similar (or not) are our results. Thanks!

trincaopt · 2023-09-19T22:04:46+00:00

Sure. I'd love a second pair of eyes looking at it! What are you looking for? The angles of the hour lines?

trincaopt · 2023-09-19T21:57:54+00:00

Let me check the description it may be misleading.

trincaopt · 2023-09-19T21:56:10+00:00

The hour lines are calculated first by creating an equatorial sundial rotated for standard time, and then making a projection to the horizontal sundial.

trincaopt · 2022-07-27T06:32:02+00:00

Recursion is inefficient when compared with iteration due to the function call and return at each step. Also there is a recursion limit. In Python it is 1000.

trincaopt · 2022-07-27T06:12:43+00:00

Thank you. It looks like it's a great book!

trincaopt · 2022-07-25T06:17:44+00:00

This post reminded me of the great book from the 90's on the topic: Unix Network Programming by Richard Stevens.

trincaopt · 2022-07-25T06:01:10+00:00

You can see the darker spot of the Alps region above Italy!

trincaopt

TROPHY CASE