![]() Solar hour angle is the measure of estimating the position of the sun relative to solar noon. You can find your latitude through Google Maps or any other standardized online map. The latitude ( ɸ) is the angle between the earth’s equator and the line drawn from the center of the earth to your location. It is 0° at the equator and 90° at the poles. The latitude of your location is the angular distance that measures how far you are from the equator. To find a better formula, follow this link: declination angle. The above equation is not very accurate and often results in an error of one or two degrees. Here, d is the number of days since the beginning of January 1st in UTC. The following equation enables to quickly calculate the declination angle: And it becomes zero at the two equinoxes (March 20th and September 22nd or 23rd). The declination angle oscillates from −23.44° to 23.44° between the two solstices of the year. This angle is the declination angle ( δ). Because of this tilt, the earth’s equator always makes an angle to the sun’s rays, as depicted in the diagram below. Instead, the axis is slightly tilted by 23.44° from the assumed position. Its axis of rotation is not perpendicular to the orbit as we might expect. Our earth revolves around the sun in a particular orbit. Let’s one-by-one understand each of the three. Therefore, we require three variables (latitude, declination, hour angle) to calculate the elevation of the sun. Here, ɑ is the solar elevation angle, δ is the declination angle, ɸ is the latitude of your location, and h is the solar hour angle. The solar elevation formula is as follows: If the angle is negative, it means it is dark the sun has either not yet risen or has transcended beyond the horizon. Thus, the angle is always zero degrees at sunrise and sunset and maximum at solar noon. The sun rises from the east and reaches its maximum altitude at solar noon. The solar elevation is the measurement of the height (or altitude) of the sun in the sky. In the above figure, ɑ1 is above 0° but less than 90° while ɑ2 & ɑ3 are closer to 0°. The solar elevation is maximum at solar noon and minimum in the morning and evening. So, the solar elevation is close to 0°, whereas, at solar noon, the solar elevation angle is highest since the sun is overhead. In the morning and evening, the sun is low in the sky, near the horizon. In simple words, it tells at what height the sun is in the sky. It is also known as the solar latitude angle and measured in degrees. The solar elevation is the angular distance between the imaginary horizontal plane on which you are standing and the sun in the sky. Solar zenith angle: What is solar elevation? ![]()
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