Calculate solar zenith angle

I want to calculate solar zenith angle for inputting a function. i tried with the available codes but didnt work out for me. Any references/guides for estimating solar zenith angle

[Image Analyst]

Probably. Did you try a web search?

TUTORIAL: How to ask a question (on Answers) and get a fast answer

[Arvind Gauns]

Yes. I had the methodology and also found some codes but it didnt work on my system

Answer 1

[Sam Chak]

Hi @Arvind Gauns

I did a web search and found the formula. It's a little strange that your browser didn't show references/guides to calculate the solar zenith angle.

Anyhow, I also tried the code and it works:

prompt1 = "What is the value of the local latitude? ";
Phi = input(prompt1)
prompt2 = "What is the value of the current declination of the Sun? ";
delta = input(prompt2)
prompt3 = "What is the value of the hour angle, in the local solar time? ";
h = input(prompt3)

theta_s = acos(sin(Phi)*sin(delta) + cos(Phi)*cos(delta)*cos(h))

[Arvind Gauns]

with a lot of trial and error the whole night, I found this way to get the solar zenith angle.

Lat         = 52.65;
Long        = 5.6;
height      = 47.5;
f1 = A(i,:);
            f = char(f1);
            yea    = f(1:4); year = str2double(yea);
            mont   = f(6:7); month = str2double(mont);
            do     = f(9:10); dom = str2double(do);
            date = datenum(year,month,dom);
            Doy     = datenum(year,month,dom)-datenum(year-1,12,31);
            hou = f(11:12); hour = str2double(hou);    
            mi = f(14:15); min= str2double(mi);
            se = f(17:18); sec=str2double(se);
            UTC = +1;
            time = ((hour - UTC)/24) + (min/(60*24)) + (sec/(60*60*24));
            cos_sza = cos(calczenithangle(Doy,time,0,0,Long,Lat));

[Lei]

Hey Arvind,

Could you please shard the function of calczenithangle?

Thanks,

Leo