- Solar azimuth angle
The "solar azimuth angle" is the

azimuth angle of thesun . It is most often defined as the angle between the line from the observer to the sun projected on the ground and the line from the observer due south. A positive azimuth angle generally indicates the sun is east of south, and a negative azimuth angle generally indicates the sun is west of south. Others define solar azimuth as the angle from due north in a clockwise direction.

It can be calculated, to a good approximation, using the following formula, however angles should be interpreted with care due to the inverse sine. "For example:" x = sin^{-1}(y) has more than one solution, therefore at a northern latitude in summer, when the azimuth at sunrise should be a positive number greater than 90 degrees, inverse of sine will incorrectly yield an angle between 0 and 90 degrees that has the same sine.:$,\; sin\; phi\_mathrm\{s\}\; =\; frac\{-sin\; h\; cos\; delta\}\{cos\; heta\_mathrm\{s$

The following two formulas can also be used to approximate the solar azimuth angle, however because these formulas utilize cosine, the azimuth angle will always be positive, and therefore, should be interpreted as the angle east of south when the hour angle, "h", is negative (morning) and the angle west of south when the hour angle, "h", is positive (afternoon).:$,\; cos\; phi\_mathrm\{s\}\; =\; frac\{cos\; h\; cos\; delta\; sin\; Phi\; -\; sin\; delta\; cos\; Phi\}\; \{cos\; heta\_mathrm\{s$

:$,\; cos\; phi\_mathrm\{s\}\; =\; frac\{sin\; heta\_mathrm\{s\}sin\; Phi\; -\; sin\; delta\}\; \{cos\; heta\_mathrm\{s\}cos\; Phi\}$

The previous formulas use the following terminology:

*$,\; heta\_mathrm\{s\}$ is thesolar elevation angle

*$,\; h$ is thehour angle of the present time

*$,\; delta$ is the current sun declination

*$,\; Phi$ is the locallatitude **See also***

Horizontal coordinate system

*Sun

*Sunrise

*Sunset **External links*** [

*http://www.nrel.gov/midc/solpos/ Solar Position Calculators by National Renewable Energy Laboratory (NREL)*]

* [*http://jamesrbass.com/sunform.aspx Azimuth and Altitude Calculator for the Sun*]

* [*http://www.ecy.wa.gov/programs/eap/models/twilight.zip An Excel workbook*] with VBA functions for solar azimuth, solar elevation, dawn, sunrise, solar noon, sunset, and dusk, by [*http://www.ecy.wa.gov/programs/eap/models.html Greg Pelletier*] , translated from NOAA's online calculators for [*http://www.srrb.noaa.gov/highlights/sunrise/azel.html solar position*] and [*http://www.srrb.noaa.gov/highlights/sunrise/sunrise.html sunrise/sunset*]

* [*http://www.ecy.wa.gov/programs/eap/models/solrad.zip An Excel workbook*] with a solar position and solar radiation time-series calculator, by [*http://www.ecy.wa.gov/programs/eap/models.html Greg Pelletier*]

*Wikimedia Foundation.
2010.*

### Look at other dictionaries:

**Solar elevation angle**— The solar elevation angle is the elevation angle of the sun. That is, the angle between the directionof the sun and the (idealized) horizon. It can be calculated, to a good approximation, using thefollowing formula::, sin heta mathrm{s} = cos h… … Wikipedia**Solar Azimuth**— The angle between the sun s apparent position in the sky and true south, as measured on a horizontal plane … Energy terms**Azimuth**— (Solar) The angle between true south and the point on the horizon directly below the sun. *** The angular distance between true south and the point on the horizon directly below the sun. Typically used as an input for opaque surfaces and… … Energy terms**Solar sail**— Solar sails (also called light sails or photon sails, especially when they use light sources other than the Sun) are a proposed form of spacecraft propulsion using large membrane mirrors. Radiation pressure is about 10 5 Pa at Earth s distance… … Wikipedia**Solar tracker**— A solar tracker is a device for orienting a solar photovoltaic panel or concentrating solar reflector or lens toward the sun. The sun s position in the sky varies both with the seasons (elevation) and time of day as the sun moves across the sky.… … Wikipedia**List of solar energy topics**— *solar activity: see) solar variation *Solar and Heliospheric Observatory *(solar array) solar panel *Solar Hot Carbon *solar azimuth angle *solar balloon *solar box cooker (solar cooking box) *solar car racing (solar panel car) *solar cell… … Wikipedia**Passive solar building design**— Elements of passive solar design, shown in a direct gain application … Wikipedia**Leaf angle distribution**— The Leaf Angle Distribution (or LAD) of a plant canopy refers to the mathematical description of the angular orientation of the leaves in the vegetation. Specifically, if each leaf is conceptually represented by a small flat plate, its… … Wikipedia**Sun path**— refers to the apparent significant seasonal and hourly positional changes of the sun (and length of daylight) as the Earth rotates, and orbits around the sun. To effectively gather solar energy, a solar collector (glass, solar panel, etc.) should … Wikipedia**Noon**— For other uses, see Noon (disambiguation). Midday redirects here. For other uses, see Midday (disambiguation). Noon time redirects here. For the song by Zion I, see Heroes in the City of Dope. Noon (also mid day or noon time) is usually defined… … Wikipedia