Satel-light data into gendaylit

Hi,

Wondering if anyone else is using Satel-light data with gendaylit. I seem to only be able to get direct horizontal irradiance (Ees, according to the glossary) rather than direct normal irradiance (Eesn) from the Satel-light database.

Can I just divide the direct horizontal irradiance by cos(altitude) to get the direct normal irradiance? Is that valid?

John Ford.

Hi john,

you find the answer directly in the gendaylit man page or just by typing
gendaylit, you just have to use the -G option - see below.

Jan

gendaylit
gendaylit: Use error - arg count
Usage: gendaylit month day hour [-P|-W|-L] direct_value diffus_value
[options]
or : gendaylit -ang altitude azimuth [-P|-W|-L] direct_value
diffus_value [options]
        -P epsilon delta (these are the Perez parameters)
        -W direct-normal-irradiance diffuse-horizontal-irradiance (W/m^2)
        -L direct-normal-illuminance diffuse-horizontal-illuminance (lux)
        -G direct-horizontal-irradiance diffuse-horizontal-irradiance
(W/m^2)
        -O [0|1|2] (0=output in W/m^2/sr visible, 1=output in W/m^2/sr
solar, 2=output in candela/m^2), default is 0

John Ford wrote:

···

Hi,

Wondering if anyone else is using Satel-light data with gendaylit. I seem to only be able to get direct horizontal irradiance (Ees, according to the glossary) rather than direct normal irradiance (Eesn) from the Satel-light database.

Can I just divide the direct horizontal irradiance by cos(altitude) to get the direct normal irradiance? Is that valid?

John Ford.

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general
  
--
Dr.-Ing. Jan Wienold
Project Manager
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings, Lighting and Daylighting
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
[email protected]
http://www.ise.fraunhofer.de

In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30

Ah, thank you. Will read the manual next time...

John.

···

On 06/11/2011, at 10:11 PM, Jan Wienold wrote:

Hi john,

you find the answer directly in the gendaylit man page or just by typing
gendaylit, you just have to use the -G option - see below.

Jan

gendaylit
gendaylit: Use error - arg count
Usage: gendaylit month day hour [-P|-W|-L] direct_value diffus_value
[options]
or : gendaylit -ang altitude azimuth [-P|-W|-L] direct_value
diffus_value [options]
       -P epsilon delta (these are the Perez parameters)
       -W direct-normal-irradiance diffuse-horizontal-irradiance (W/m^2)
       -L direct-normal-illuminance diffuse-horizontal-illuminance (lux)
       -G direct-horizontal-irradiance diffuse-horizontal-irradiance
(W/m^2)
       -O [0|1|2] (0=output in W/m^2/sr visible, 1=output in W/m^2/sr
solar, 2=output in candela/m^2), default is 0

John Ford wrote:

Hi,

Wondering if anyone else is using Satel-light data with gendaylit. I seem to only be able to get direct horizontal irradiance (Ees, according to the glossary) rather than direct normal irradiance (Eesn) from the Satel-light database.

Can I just divide the direct horizontal irradiance by cos(altitude) to get the direct normal irradiance? Is that valid?

John Ford.

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

--
Dr.-Ing. Jan Wienold
Project Manager
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings, Lighting and Daylighting
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
[email protected]
http://www.ise.fraunhofer.de

In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general