wxastronomy

[SergiosK]

Hello, i have a problem with moon icon at index.php and wxastronomy.php.
I have 41% illuminate and the moon icon shows over 55%.
I have seen that to other pages.
Here is what i get into my local http://www.komokaweather.com/wxastronomy.php
Exactly the same problem.
When i go to cumulus web template the icon of cumulus is correct.At saratoga is wrong. It gives me the moon22.gif.
The same is at saratoga page http://saratoga-weather.org/index.php (moon icon on index)
And when i go to http://saratoga-weather.org/sunmoon.php goes to correct (correct moon icon)
Why happened that?
Thank you

[saratogaWX]

It looks like there's been a small change at the USNO website such that queries based on lat/long of site do not return the line like

Phase of the Moon on 30 June: waning crescent with 44% of the Moon's visible disk illuminated.

which is used to determine the percent illumination and phase name.

That line is missing in the the USNO return when a latitude/longitude query is used (and was present before).

The wxastronomy page then uses the built-in tables to approximate what the phase and illumination percent are, and that approximation may differ from what Cumulus (or some other weather software) return based on their built-in calculations.

Unfortunately, I didn't have a good calculation algorithm for moon phase/illumination in PHP that matched the output of the USNO (the 'Gold Standard') or even the built-in versions in some weather software (which did not always agree with each other or with the USNO).

So.. I am sorry that the illumination is a bit off now. I'll see what the USNO has to say about the website change.

I had used the combination of the approximation routines + the USNO query in order to support multiple weather software with astronomical data as some of the supported software with the templates lacked the built-in variables that were needed.

Best regards,
Ken

[SergiosK]

Your illuminitation algorithm is ok and works very well. The problem is the image that loads is wrong.
If you see here http://www.calculatorcat.com/moon_phases/phasenow.php the illuminitation is 38% the same as my page (your algorithm code) but the image that it loads is wrong.See the attach image that load in wxastronomy.(thats not 38% its more than 50%)

[SergiosK]

Hello again, i have found a code from you Ken and i fix the problem from now. The code is from the weather-watch.
If someone have the same problem with me the code is http://www.weather-watch.com/smf/index. ... .395;imode
Two files must edit, wxastronomy.php and ajax-dashboard.php
I will upload it to help.
Thanks again Ken.

[William Grimsley]

Any news, Ken?

[saratogaWX]

I've examined the mods, and I will not be incorporating them into the distribution. The main reasons are two-fold:

1) the moon icon is directly fetched from the USNO website at http://tycho.usno.navy.mil/cgi-bin/phase.gif - it is a very accurate
depiction of the current illumination phase of the moon, but I don't want to needlessly use the external website (USNO) for getting
a near-realtime picture when the 30 local images of the moon in ./ajax-images/ serve the purpose efficiently as static images.

2) the sun image on wxastronomy.php is likewise from NASA http://umbra.nascom.nasa.gov/images/lat ... mbnail.gif and again, I didn't want to default to using an external website image for the page when a static image would suffice. Also, the code checking for current weather station definition seemed to be missing and I needed that for support for all weather stations, not just Cumulus.

You are free to use the modified versions as you like -- I just won't be using those mods for the distribution based on the above reasons.

Best regards,
Ken

[William Grimsley]

Hi Ken,

Ok, thanks for that. I will leave my moon icons and sun icons as they are for now until the next distribution is available.

Best regards,

William