Name

CL_gm_sunZenithAngle — Sun zenith angle and sun azimuth in function of latitude, sun declination and local hour of a Earth's point.

Calling Sequence

   [AngZen,AzSol] = CL_gm_sunZenithAngle(lat,decl,hloc)
   
   

Description

  • Given one Earth point's latitude,local hour and sun declination , this function computes the angle between the zenith of the point and sun direction (Sun Zenith Angle) and the corresponding sun azimuth
  • Last update : 24/11/2008

Parameters

AngZen:

Earth point's sun zenith angle [deg] (MxNxP)

AzSol:

Earth point's sun azimuth angle [deg] (MxNxP)

lat:

vector of latitudes [deg] (Mx1)

decl:

vector of sun declinations [deg] (Nx1)

hloc:

vector of local hours [deg] (Px1)

Bibliography

Satellites Orbites et Missions (M Capderou)

Authors

CNES - DCT/SB

See also

Examples

//example 1
lat = [10;20;30];
decl= [0;15;23];
hloc= [45;60];
[AngZen,AzSol] = CL_gm_sunZenithAngle(lat,decl,hloc)

//example 2
lat = [60];
hloc = (0:-7.5:-172.5);
hloc = [hloc,(-180:7.5:-7.5)];
hloc = hloc';
dates=(23011:23375);
[r_sun,rs] = CL_mod_moonSunG50(dates,'s');
pos_sph = CL_co_car2sph(r_sun);
decl = pos_sph(2,:);
decl = decl'*%CL_rad2deg;
mtzPlot=[];
sizHloc1=size(hloc);
nLigHloc1=sizHloc1(1);
sizDecl1=size(decl);
nLigDecl1=sizDecl1(1);
sizLat1=size(lat);
nLigLat1=sizLat1(1);
[AngZen,AzSol] = CL_gm_sunZenithAngle(lat,decl,hloc)
mtzPlot=matrix(AngZen,nLigDecl1,nLigHloc1);
mtzPlot=mtzPlot';
xset("colormap",jetcolormap(180))
Matplot(mtzPlot);
ax=gca();
ax.title.text= "Sun Zenith Angle";
ax.x_label.text= "Temps(jours)";
ax.y_label.text= "Heure locale";
ax.font_size=2;
ax.title.font_size=2;
ax.x_label.font_size=2;
ax.y_label.font_size=2;
ax.y_ticks.labels=["11.5" "14" "16.5" "19" "21.5" "0" "2.5" "5" "7.5" "10" "12.5"];