Message text written by "Roger Bailey" >Hi Fernando, For specific data inputs of date, time and location, the following website calculates the solar ephemeris and gives you the altitude and azimuth for your location. http://arthemis.na.astro.it:6563/themis/owa/solar.coordinates
The Dialists Companion which you can download from the NASS website http://www.sundials.org does the same thing. I use it on a routine basis for such calculations. It is more convenient because you can install it on your computer. Both of these give specific numbers back for each data set that you enter. Neither of these will produce a table of all the data. Inputting 13 x 365 = 4745 data sets is tedious. What you need is a spreadsheet or program that takes inputs of your location, calculates the solar ephemeris (declination and hour angle) to the required accuracy, calculates the altitude and azimuth, and then prints the huge output table. It is not a difficult programming task. The mathematical algorithms are well known, but I do not know of anyone who has offered the table of outputs that I think you are looking for. Roger Bailey Walking Shadow Designs 51 N 115 W< In my view, the best approach to this problem is to use Solar Calc: http://www.gcstudio.com/cgi-bin/sunpage (select the Text output rather than the HTML one if you want decimal degrees rather than degrees and minutes.) This web site lists data over a period and with any specified interval. It is a one-shot solution to the problem whereas other approaches require repetitive data entry and/or a spreadsheet to sort out the data. NB you should be careful when using the NASS Companion for altitude information since the necessary refraction correction - although it is calculated and displayed - is NOT included in the apparent altitude figures that are listed. Apparent solar altitude is therefore incorrect unless you yourself apply the stated correction. Patrick
