Hour angle Calculator

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✖The Solar Time is a calculation of the passage of time based on the position of the Sun in the sky. It is taken in a 24-hour format. For e.g. 6PM is 18:00 hours.ⓘ Solar Time [ST]

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✖The hour angle at any instant is the angle through which the earth has to turn to bring the meridian of the observer directly in line with the sun's rays.ⓘ Hour angle [ω]

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Formula

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Hour angle

Formula

`"ω" = ("ST"/3600-12)*15*0.0175`

Example

`"0.7875rad"=("54000s"/3600-12)*15*0.0175`

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Hour angle Solution

STEP 0: Pre-Calculation Summary

Formula Used

Hour angle = (Solar Time/3600-12)*15*0.0175
ω = (ST/3600-12)*15*0.0175
This formula uses 2 Variables

Variables Used

Hour angle - (Measured in Radian) - The hour angle at any instant is the angle through which the earth has to turn to bring the meridian of the observer directly in line with the sun's rays.
Solar Time - (Measured in Second) - The Solar Time is a calculation of the passage of time based on the position of the Sun in the sky. It is taken in a 24-hour format. For e.g. 6PM is 18:00 hours.

STEP 1: Convert Input(s) to Base Unit

Solar Time: 54000 Second --> 54000 Second No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

ω = (ST/3600-12)*15*0.0175 --> (54000/3600-12)*15*0.0175

Evaluating ... ...

ω = 0.7875

STEP 3: Convert Result to Output's Unit

0.7875 Radian --> No Conversion Required

FINAL ANSWER

0.7875 Radian <-- Hour angle

(Calculation completed in 00.004 seconds)

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Credits

Created by ADITYA RAWAT

DIT UNIVERSITY (DITU), Dehradun

ADITYA RAWAT has created this Calculator and 50+ more calculators!

Verified by Abhishek Dharmendra Bansile

Vishwakarma Institute of Information Technology, Pune (VIIT Pune), Pune

Abhishek Dharmendra Bansile has verified this Calculator and 10+ more calculators!

< 8 Basics Calculators

Angle of incidence of sun rays

Go Angle Of Incidence = acos(sin(Latitude Angle)*(sin(Declination Angle)*cos(Tilt Angle)+cos(Declination Angle)*cos(Surface Azimuth Angle)*cos(Hour angle)*sin(Tilt Angle))+cos(Latitude Angle)*(cos(Declination Angle)*cos(Hour angle)*cos(Tilt Angle)-sin(Declination Angle)*cos(Surface Azimuth Angle)*sin(Tilt Angle))+cos(Declination Angle)*sin(Surface Azimuth Angle)*sin(Hour angle)*sin(Tilt Angle))

Hour Angle at Sunrise and Sunset

Go Hour angle = acos(-tan(Latitude Angle-Tilt Angle)*tan(Declination Angle))

Daylight Hours

Go Daylight Hours = 3600*acos(-tan(Latitude Angle)*tan(Declination Angle))

Tilt factor for reflected radiation

Go Tilt factor for reflected radiation = (Reflectivity*(1-cos(Tilt Angle)))/2

Energy Conversion Efficiency of Solar Chimney

Go Max Efficiency of a Solar Chimney = 9.81*Height of Chimney/(1005*Ambient Air Temperature)

Tilt factor for diffused radiation

Go Tilt factor for diffused radiation = (1+cos(Tilt Angle))/2

Declination angle

Go Declination Angle = 23.45*sin(0.9863*(284+Number of days))

Hour angle

Go Hour angle = (Solar Time/3600-12)*15*0.0175

Hour angle Formula

Hour angle = (Solar Time/3600-12)*15*0.0175
ω = (ST/3600-12)*15*0.0175

Solar hour angle (ω)

The hour angle of a point on the earth’s surface is the angle through which the earth would turn to bring the meridian of the point directly under the sun. The earth is rotating, so this angular displacement represents time. So in observing the sun from earth, the solar hour angle is an expression of time, expressed in angular measurement, usually degrees, from the solar noon.

How to Calculate Hour angle?

Hour angle calculator uses Hour angle = (Solar Time/3600-12)*15*0.0175 to calculate the Hour angle, The Hour angle formula converts the local solar time (LST) into the number of degrees which the sun moves across the sky. Hour angle is denoted by ω symbol.

How to calculate Hour angle using this online calculator? To use this online calculator for Hour angle, enter Solar Time (ST) and hit the calculate button. Here is how the Hour angle calculation can be explained with given input values -> -3.004167 = (54000/3600-12)*15*0.0175.

FAQ

What is Hour angle?

The Hour angle formula converts the local solar time (LST) into the number of degrees which the sun moves across the sky and is represented as ω = (ST/3600-12)*15*0.0175 or Hour angle = (Solar Time/3600-12)*15*0.0175. The Solar Time is a calculation of the passage of time based on the position of the Sun in the sky. It is taken in a 24-hour format. For e.g. 6PM is 18:00 hours.

How to calculate Hour angle?

The Hour angle formula converts the local solar time (LST) into the number of degrees which the sun moves across the sky is calculated using Hour angle = (Solar Time/3600-12)*15*0.0175. To calculate Hour angle, you need Solar Time (ST). With our tool, you need to enter the respective value for Solar Time and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

How many ways are there to calculate Hour angle?

In this formula, Hour angle uses Solar Time. We can use 1 other way(s) to calculate the same, which is/are as follows -

Hour angle = acos(-tan(Latitude Angle-Tilt Angle)*tan(Declination Angle))

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