What do you mean by 'Noon Sun angle'? How do you specify that?
I call it angle of 'dip', the angle away from the zenith in the local sky, of a place (hence it is location or Latitude dependent - as Longitude translates as time & Noon is specific to that Longitude, fixing that place's Longitude).
How to go about it? Erect a perfectly vertical column, post (like a lamp post or flag post). I think it is called a Gnomon. Needless to say it shall be in a place where no other shadow falls of trees or buildings. Know the height (from base to the tip) and I prefer an accurate height of 10 feet (makes computing easy). Make a wide area at the base a perfectly horizontal (hence flat) plane, on which the shadow due to the Sun falls.
Noon Sun has its shadow along the North-South line. For knowing that mark the shortest shadow. Here we concern with only Northern Hemisphere (and shadows to South).
Dip = Latitude - (Solar) Declination
dip = lat-decl.
April 11 : It is 21 days after the Vernal Equinox (March 21). So Sun's declination (Earth orbital inclination is 23°.45) is given in
Answers & Comments
What do you mean by 'Noon Sun angle'? How do you specify that?
I call it angle of 'dip', the angle away from the zenith in the local sky, of a place (hence it is location or Latitude dependent - as Longitude translates as time & Noon is specific to that Longitude, fixing that place's Longitude).
How to go about it? Erect a perfectly vertical column, post (like a lamp post or flag post). I think it is called a Gnomon. Needless to say it shall be in a place where no other shadow falls of trees or buildings. Know the height (from base to the tip) and I prefer an accurate height of 10 feet (makes computing easy). Make a wide area at the base a perfectly horizontal (hence flat) plane, on which the shadow due to the Sun falls.
Noon Sun has its shadow along the North-South line. For knowing that mark the shortest shadow. Here we concern with only Northern Hemisphere (and shadows to South).
Dip = Latitude - (Solar) Declination
dip = lat-decl.
April 11 : It is 21 days after the Vernal Equinox (March 21). So Sun's declination (Earth orbital inclination is 23°.45) is given in
Sin[21(360/365.25)] = Tan(decl) . Cot(23°.45)
decl. = ArcTan{ Tan(23°.45) . Sin[21(360/365.25)] }.
i) latitude 0° : dip = 0 - decl = - ArcTan{ Tan(23°.45) . Sin[21(360/365.25)] },
Negative figure in respect to South, implies the shadow falls (points to) North.
ii) latitude 0° : dip = 40°N - decl = 40° - ArcTan{ Tan(23°.45) . Sin[21(360/365.25)] },