Sun Moon plot

[gluepack]

Anything to brighten up the website...

I looked at http://www.horca.net/graphs/sunplot.php but quickly discovered the times were all off.

Then, by changing the longitude and utc time to negative, the sun times seem ok but the moon times don't appear to be (compared to whatever it is that the ajax dashboard uses , which is what I assumed Cumulus used but I see the moon times are slightly different there).

Anyway, I don't want to use it when the times vary so radically from the dashboard so, is there another similar "product" (i.e. aesthetically pleasing graphical image) available anywhere that gives correct results or, anyone know which is correct?

For example, the above php (or http://www.horca.net/graphs/sunplotjava.html) show
sunrise 5:37 sunset 20:38 moonrise 01:02 moonset 11:23 whereas the dashboard is showing..
sunrise 5:34 sunset 20:32 moonrise 00:26 moonset 11:26 and Cumulus is showing...
sunrise 5:34 sunset 20:32 moonrise 00:30 moonset 11:25

I don't mind the few minutes difference (well, I do, but I guess I can tolerate it) but 1/2 hour difference in moonrise isn't really acceptable.

[steve]

I'd be quite prepared to believe that the Cumulus moonrise time is actually for yesterday or tomorrow, hence the large discrepancy. A difference of about that size would correspond to a day's difference. The components I use to do the calculations are problematic and not at all easy to use, and there are other issues involving high latitudes, as I discovered yesterday.

Having said that, if the dashboard isn't getting its figures from Cumulus, as it would appear it isn't, then perhaps 'we' are correct, and it's the other one that's a day out...

Edit: I tried this site: http://www.sunrisesunsetmap.com/ and the times for my location agree with Cumulus (within a few minutes).

[gluepack]

Thanks.

Well, I tried http://www.moonsigncalendar.net/calcula ... &Jahr=2013 and it gave the following (catering for EEST)....

sunrise: 05:34 sunset: 20:42 moonrise: 00:27 moonset: 11:26

and the link you gave is...
sunrise: 05:34 sunset: 20:42 moonrise: 00:25 moonset: 11:27

which leans more towards the ajax dashboard than Cumulus but still pretty close and, unfortunately, emphasises that the sunplot.php is incorrect, i.e. out by 1/2 hour on moonrise.

Well, I'll keep looking to see if there is another aesthetically pleasing graph/set of data out there.

[mcrossley]

Any calculations involving the Moon get complex quickly if you want any degree of accuracy. I would treat the USNO as one of the definitive sources on the web if you want to compare figures. As Steve has found some of the popular approximations are only valid between moderate latitudes, where they give figures within a few minutes, but break down at higher latitudes.

I learnt how hard it is to implement these routines when I wrote my own in JavaScript using Meeus 's book, my routines are accurate to better than a minute.

Edit: typed and corrected on my tablet

[olsongt]

Redid the calculation engines and reformatted the main page for the sun graph at:

gartholson.net/horca/sun

see if the times work better now.

[gluepack]

Thanks.

The sun times are spot on, compared to the Ajax dashboard & the sun/moon almanac but the moon times are way, way off.

The two above both show rise 00.02 and set 12.36 (which corresponds to http://www.timeanddate.com/worldclock/a ... oon&n=2272)
whereas your plot shows rise 15.36 and set 03.31


p.s. reverse yours and subtract 3 hours (difference between me and UTC) and
set 12.36 and rise 00.31
will apply exactly to moonset today and moonrise tomorrow morning, if that helps

[olsongt]

Oops, got the lat/lon mixed up on the input data. Works now I think.

[gluepack]

Spot on. Thanks!

I have incorporated it into my Sun/Moon Almanac web page, calling your php script. I hope that is ok.

viz. http://www.jerbils.info/saratoga/wxastronomy.php

[gluepack]

Oh, not sure if this is a problem or not...

Dashboard shows waxing crescent 9% illuminated whereas the plot shows 91.5%.

I guess it depends what is meant by 91.5% but you would think it would be "illuminated" so shouldn't it be 100 - 91.5 = 8.5%

[gluepack]

I haven't checked the page where I display this plot for a while so I don't know when it stopped operating.
I don't think I have an email address and the site is password protected with no contact details.
I can display the page where the calculation is done but no graph displays.
Any idea what the problem is?

[beteljuice]

His server must have upped the PHP version.

That is a new version 'error' reffering to a bit of the code that now needs to be rewritten