Re: Solar math
Dear Dan, The free open source software TriSph can directly compute this problem. You can download it here : http://gnomonique.fr/trisph/index_en.htm Yvon Le 22/03/2018 21:58, sundial-requ...@uni-koeln.de a écrit : -- Message: 3 Date: Thu, 22 Mar 2018 16:47:08 +0200 From: Dan-George Uza To: Sundial List Subject: Solar math Message-ID: Content-Type: text/plain; charset="utf-8" Dear all, given the azimuth and altitude of a point in the sky, what would be the best way of finding the dates and times during which the Sun reaches that point? Is there any software for this? Dan Uza --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Fwd: Solar math
The attached mail from Frans Maes was erroneously sent to me only. I wish to add that the same "trick" can be done with Sol Et Umbra using the commands at the bottom of the display. Ciao. Gian -- Forwarded message -- From: Maes, F.W. Date: 2018-03-22 21:00 GMT+01:00 Subject: Re: Solar math To: Gian Casalegno Hi Dan, Another, free solution would be to use www.esrl.noaa.gov/gmd/grad/solcalc/. After giving in latitude, date and time, it provides solar azimut and altitude (= elevation). I have used it the way you are looking for. Just start entering a guessed pair of date/time values, look at the resulting Az/El pair, adapt the date/time values into the direction that will improve the fit, etc, until the outcome is within acceptable range. When starting with an 'educated guess', it may take only 3-4 iterations to arrive at a satisfactory solution. Best regards, Frans Maes <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virusvrij. www.avg.com <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#m_5557836997448977438_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Thu, Mar 22, 2018 at 7:34 PM, Gian Casalegno wrote: > Dan, > the program AlmSun by Rafał Tomasik can compute the instant when the sun > reaches the desired azimuth and height. > More info can be found at http://almsun.pl/en/ > > Actually it is not freeware but it requires a small payment (it was 19 $ > two years ago). > > Ciao. > Gian > > > 2018-03-22 15:47 GMT+01:00 Dan-George Uza : > >> Dear all, given the azimuth and altitude of a point in the sky, what >> would be the best way of finding the dates and times during which the Sun >> reaches that point? Is there any software for this? >> >> Dan Uza >> >> --- >> https://lists.uni-koeln.de/mailman/listinfo/sundial >> >> >> > > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Solar math
Dan, the program AlmSun by Rafał Tomasik can compute the instant when the sun reaches the desired azimuth and height. More info can be found at http://almsun.pl/en/ Actually it is not freeware but it requires a small payment (it was 19 $ two years ago). Ciao. Gian 2018-03-22 15:47 GMT+01:00 Dan-George Uza : > Dear all, given the azimuth and altitude of a point in the sky, what would > be the best way of finding the dates and times during which the Sun reaches > that point? Is there any software for this? > > Dan Uza > > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Solar math
I don't know any software, but my approach would be: 1. Use Altitude and Azimuth and Latitude to calculate Declination (straightforwad Spherical Trig calculation. If you need formula, it will take me a moment to come up with it) 2. Calculate dates for the declination (longitude/time zone will matter). This should not be too hard to look up (or should be findable at link below) 3. Calculate time from declination, location, time zone, daylight saving. OR create an azimuth/altitude table for a given date at http://aa.usno.navy.mil/data/docs/topocentric.php . Be sure to select for Apparent Topocentic Zenith Distance and Azimuth. Times are given in UTC. -Bill On Thu, Mar 22, 2018 at 10:47 AM, Dan-George Uza wrote: > Dear all, given the azimuth and altitude of a point in the sky, what would > be the best way of finding the dates and times during which the Sun reaches > that point? Is there any software for this? > > Dan Uza > > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Solar math
Dear all, given the azimuth and altitude of a point in the sky, what would be the best way of finding the dates and times during which the Sun reaches that point? Is there any software for this? Dan Uza --- https://lists.uni-koeln.de/mailman/listinfo/sundial
