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is near the annual average for rural-city areas. The Linke
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factor for an absolutely clear atmosphere is <i>lin</i>=1.0. See notes below
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to learn more about this factor. The incidence solar angle is the angle between
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horizon and solar beam vector. The solar radiation maps for given day are
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computed integrating the relevant irradiance between sunrise and sunset times
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for given day. The user can set finer or coarser time step <i>step</i> used
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for all-day radiation calculations. A default value of <i>step</i> is 0.5
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hour. Larger steps (e.g. 1.0-2.0) can speed-up calculations but produce less
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reliable results. The output units are in Wh per squared meter per given
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horizon and solar beam vector.
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The solar radiation maps for a given day are computed by integrating the
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relevant irradiance between sunrise and sunset times for that day. The
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user can set a finer or coarser time step used for all-day radiation
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calculations with the <i>step</i> option. The default value of <i>step</i> is
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0.5 hour. Larger steps (e.g. 1.0-2.0) can speed-up calculations but produce
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less reliable (and more jagged) results. As the sun moves through approx.
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15° of the sky in an hour, the default <i>step</i> of half an hour will
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produce 7.5° steps in the data. For relatively smooth output with the
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sun placed for every degree of movement in the sky you should set the
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<i>step</i> to 4 minutes or less. <i>step</i><tt>=0.05</tt> is equivalent
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to every 3 minutes. Of course setting the time step to be very fine
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proportionally increases the module's running time.
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The output units are in Wh per squared meter per given
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day [Wh/(m*m)/day]. The incidence angle and irradiance/irradiation maps can
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be computed without shadowing influence of relief by default or they can
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be computed with this influence using the flag <i>-s</i>. In mountainous areas