Modelling sky using sky scanner MS-321LR

Dear All,

I try to model sky and daylight using measured data from sky scanner.

I want to know is it possible to convert radiance or luminance of each
patch to rgb and use 145 primitive of type source to model the sky? or my
assumptions are wrong?

Cheers,
Ehsan

Hi Ehsan,

Dr.John Mardaljevic in his PhD study have used Sky Scanner, and I guess
also the RGB way.
The study can be found here:
http://climate-based-daylighting.com/doku.php?id=resources:thesis

Vaib

···

On 6 April 2014 19:24, Ehsan M.Vazifeh <[email protected]> wrote:

Dear All,

I try to model sky and daylight using measured data from sky scanner.

I want to know is it possible to convert radiance or luminance of each
patch to rgb and use 145 primitive of type source to model the sky? or my
assumptions are wrong?

Cheers,
Ehsan

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

Hi Ehsan,

as far as I understand the scan pattern used by the scanner is close enough to the Tregenza patches to use it with dctimestep and daylight coefficients. To get an idea of the format expected by that tool, have a look at the output of gendaylit.

Be aware that the sun is excluded in the measurements, so you will have to find a way to get the direct sun contribution. As there are no "color channels" in the measurement, you would use the luminance readings and apply them to all three channels in Radiance equally (R=G=B).

Cheers, Lars.

···

Dear All,

I try to model sky and daylight using measured data from sky scanner.

I want to know is it possible to convert radiance or luminance of each patch to rgb and use 145 primitive of type source to model the sky? or my assumptions are wrong?

Cheers,
Ehsan

Dear Lars,

As I understood correctly I have just distribution of diffuse using sky
scanner. So I need to include the sun separately. Now I have two questions:
1) what is 10 real arguments in the sky scene generated by gendaylit (below
you will find the example)

void brightfunc skyfunc
2 skybright perezlum.cal
0
10 3.114e+01 2.426e+01 -0.989445 -0.210729 22.988 -5.9264
   1.398847 -0.010398 -0.415479 0.909543

2) why when we generate a sky for instance with sun description, we should
always include the sky scene as a glowing source otherwise the illuminance
values will be zero.

I guess I have some fundamental misunderstanding about the sky scene
description. It would be real help if I can get some explanation why this
happens.

CHeers,
Ehsan

···

On Mon, Apr 7, 2014 at 11:05 AM, Lars O. Grobe <[email protected]> wrote:

Hi Ehsan,

as far as I understand the scan pattern used by the scanner is close
enough to the Tregenza patches to use it with dctimestep and daylight
coefficients. To get an idea of the format expected by that tool, have a
look at the output of gendaylit.

Be aware that the sun is excluded in the measurements, so you will have to
find a way to get the direct sun contribution. As there are no "color
channels" in the measurement, you would use the luminance readings and
apply them to all three channels in Radiance equally (R=G=B).

Cheers, Lars.

Dear All,

I try to model sky and daylight using measured data from sky scanner.

I want to know is it possible to convert radiance or luminance of each
patch to rgb and use 145 primitive of type source to model the sky? or my
assumptions are wrong?

Cheers,
Ehsan

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

Ehsan,

If you check the "perezlum.cal" file, you will see what the 10 values are:

* All-weather Angular Sky Luminance Distribution .*

* Additional arguments required for calculation of skybright:*

* A1 - diffus normalization*
* A2 - ground brightness*
* A3,A4,A5,A6,A7 - coefficients for the Perez model*
* A8,A9,A10 - sun direction*

Regarding your second question about why do we need to add the glow source;
that is because the material created by "gendaylit" or "gensky" is actually
a modifier. That modifier is what gives the sky semi-hemisphere and the
ground semi-hemisphere the correct luminance for each angle, representing
different sky models.

Why does not the program just write the Glow Source as well? No idea...

I hope it helps!

German

···

2014-04-07 14:03 GMT-03:00 Ehsan M.Vazifeh <[email protected]>:

Dear Lars,

As I understood correctly I have just distribution of diffuse using sky
scanner. So I need to include the sun separately. Now I have two questions:
1) what is 10 real arguments in the sky scene generated by gendaylit
(below you will find the example)

void brightfunc skyfunc
2 skybright perezlum.cal
0
10 3.114e+01 2.426e+01 -0.989445 -0.210729 22.988
-5.9264 1.398847 -0.010398 -0.415479 0.909543

2) why when we generate a sky for instance with sun description, we should
always include the sky scene as a glowing source otherwise the illuminance
values will be zero.

I guess I have some fundamental misunderstanding about the sky scene
description. It would be real help if I can get some explanation why this
happens.

CHeers,
Ehsan

On Mon, Apr 7, 2014 at 11:05 AM, Lars O. Grobe <[email protected]> wrote:

Hi Ehsan,

as far as I understand the scan pattern used by the scanner is close
enough to the Tregenza patches to use it with dctimestep and daylight
coefficients. To get an idea of the format expected by that tool, have a
look at the output of gendaylit.

Be aware that the sun is excluded in the measurements, so you will have
to find a way to get the direct sun contribution. As there are no "color
channels" in the measurement, you would use the luminance readings and
apply them to all three channels in Radiance equally (R=G=B).

Cheers, Lars.

Dear All,

I try to model sky and daylight using measured data from sky scanner.

I want to know is it possible to convert radiance or luminance of each
patch to rgb and use 145 primitive of type source to model the sky? or my
assumptions are wrong?

Cheers,
Ehsan

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

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

--
*Germán Molina L.*
Ingeniero Trainee
Hunter Douglas Chile S.A.
Celular +569 89224445

--

*Nota de Confidencialidad:* Este mensaje incluído los archivos adjuntos son
confidenciales y pueden contener informacion privilegiada protegida por
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gracias.

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including any attachment, is confidential and is intended only for the
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···

http://www.iesd.dmu.ac.uk/~jm/lib/exe/fetch.php?media=resources:mardaljevic_chap5.pdf

A1
- diffus normalization
9
A2
- ground brightness
10
A3,A4,A5,A6,A7
- coefficients for the Perez model
11
A8,A9,A10
- sun direction

Dear Lars and German,

It was a really a comprehensive explanation. I was always concerned about
sky model why its like that. Thank you for the quite useful and important
information you gave to me.

Cheers,
Ehsan

···

On Tue, Apr 8, 2014 at 11:56 AM, Lars O. Grobe <[email protected]> wrote:

--------
WARNING: At least one of the links in the message below goes to an .exe
file,
which could be malicious. To learn how to protect yourself, please go here:
https://commons.lbl.gov/x/_591B
--------
Hi Ehsan,
German already gave the answers, I just want to add some.

1) what is 10 real arguments in the sky scene generated by gendaylit
(below you will find the example)

For a description of the Perez sky model, see page 175 of John's thesis:

http://www.iesd.dmu.ac.uk/~jm/lib/exe/fetch.php?media=resources:mardaljevic_chap5.pdf

The ten arguments are explained in perezlum.cal:

  A1 - diffus normalization 9 A2 - ground brightness 10 A3,A4,A5,A6,A7 -
coefficients for the Perez model 11 A8,A9,A10 - sun direction

2) why when we generate a sky for instance with sun description, we should
always include the sky scene as a glowing source otherwise the illuminance
values will be zero.

The sky generators in Radiance output modifiers, just as German mentioned.
This modifiers "scale" the brightness of whatever you apply them to.

In most cases, you will scale a glow applied to a hemisphere (modeled as a
distant source) of brightness 1, as the generator will give you brightness
in absolute values by default. In this case, the result of the generator
would directly match the sky brightness in your scene.

However, if you want color, you would first define the brightness of a
glow material in a way that your normalize the desired color to 1, and than
apply the modifier to this colored glow material. The modified glow
material would keep the color you wanted, but scale this according to the
sky model.

In other cases, if you have no geometry outside the space you are
interested in, you can even apply the modifier to a glow of uniform
brightness of one applied to the window-plane.

So there are many ways you can make use of the distribution, and including
any kind of geometry into the output of the sky generator would just limit
its applications.

Cheers, Lars.

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Radiance-general mailing list
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Hi Ehsan,

Perhaps it's been mentioned already, but if you go for the 145 source angles remember to correct for the missing solid angle by scaling the patch radiance values accordingly.

Cheers
John

John Mardaljevic
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 (Direct)
Tel: +44 1509 228529 (Pam Allen, secretary)

[email protected]<mailto:[email protected]>

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn/

Personal daylighting website:
http://climate-based-daylighting.com<http://climate-based-daylighting.com/>

Dear Professor Mardaljevic,

As I understood, to use the source method for modeling the 145 patches of
Tregenza. First of all, I have to calculate the ratio of (disk area of the
patch divided by real area of each patch), then multiply it by radiance of
each patch. is it right?
Second, in this case, I will have some dark points between the disks which
look like diamonds. Unfortunately, by now I didn't find the time to
implement a code to create these disks.
Thank you for the consideration and support.

Best Regards,
Ehsan

···

On Sat, Apr 12, 2014 at 1:41 PM, John Mardaljevic <[email protected] > wrote:

Hi Ehsan,

Perhaps it's been mentioned already, but if you go for the 145 source
angles remember to correct for the missing solid angle by scaling the patch
radiance values accordingly.

Cheers
John

    John Mardaljevic
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 (Direct)
Tel: +44 1509 228529 (Pam Allen, secretary)

[email protected]

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn/

Personal daylighting website:
http://climate-based-daylighting.com

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

Hi Ehsan,

Yes, that's right -- you simply scale the measured (circular patch) luminance or radiance values by the ratio of the 'rectangular' patch solid angle to the circular source solid angle, i.e. some factor > 1. Your sky will of course not be continuous, but at least the total luminous output will be realistic. See table 3-7, p70 in Chapter 3 here:

http://climate-based-daylighting.com/doku.php?id=resources:thesis

Another way is to use the measured data to create a 'brightdata' representation of the sky, which will be continuous. How that is done is also described in Chapter 3.

Cheers
John

John Mardaljevic PhD FSLL
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 (Direct)
Tel: +44 1509 228529 (Pam Allen, secretary)

[email protected]

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn

Personal daylighting website:
http://climate-based-daylighting.com

Thank you very much! I will try to use both methods.

Cheers,
Ehsan

···

On Mon, Apr 14, 2014 at 3:13 PM, John Mardaljevic <[email protected] > wrote:

Hi Ehsan,

Yes, that's right -- you simply scale the measured (circular patch)
luminance or radiance values by the ratio of the 'rectangular' patch solid
angle to the circular source solid angle, i.e. some factor > 1. Your sky
will of course not be continuous, but at least the total luminous output
will be realistic. See table 3-7, p70 in Chapter 3 here:

http://climate-based-daylighting.com/doku.php?id=resources:thesis

Another way is to use the measured data to create a 'brightdata'
representation of the sky, which will be continuous. How that is done is
also described in Chapter 3.

Cheers
John

John Mardaljevic PhD FSLL
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 (Direct)
Tel: +44 1509 228529 (Pam Allen, secretary)

[email protected]

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn

Personal daylighting website:
http://climate-based-daylighting.com

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

--
Dipl. Ing. Ehsan, M. Vazifeh
Project Assistant
Department of Building Physics and Building Ecology
Vienna University of Technology
Karlsplatz 13, A-1040 Vienna, Austria
Tel +43 1 58801 27003
Fax +43 1 58801 27093
[email protected]
www.bpi.tuwien.ac.at

Dear All,

I am calculating now the RGB Luminance for each patch of Tregenza. If lets
say I have a radiance of 200 W/(sr.m^2) then the luminance for red will be
200*0.265*179, green will be 200*0.67*179, and blue will be 200*0.065*179
?!!
or I should simply say R=G=B=200/3*179??

Thanks a lot.
Ehsan

···

On Mon, Apr 14, 2014 at 4:37 PM, Ehsan M.Vazifeh <[email protected]>wrote:

Thank you very much! I will try to use both methods.

Cheers,
Ehsan

On Mon, Apr 14, 2014 at 3:13 PM, John Mardaljevic < > [email protected]> wrote:

Hi Ehsan,

Yes, that's right -- you simply scale the measured (circular patch)
luminance or radiance values by the ratio of the 'rectangular' patch solid
angle to the circular source solid angle, i.e. some factor > 1. Your sky
will of course not be continuous, but at least the total luminous output
will be realistic. See table 3-7, p70 in Chapter 3 here:

http://climate-based-daylighting.com/doku.php?id=resources:thesis

Another way is to use the measured data to create a 'brightdata'
representation of the sky, which will be continuous. How that is done is
also described in Chapter 3.

Cheers
John

John Mardaljevic PhD FSLL
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 (Direct)
Tel: +44 1509 228529 (Pam Allen, secretary)

[email protected]

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn

Personal daylighting website:
http://climate-based-daylighting.com

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

Ehsan,

I understand you can't find the R,G and B values from the total luminance
values (i.e. finding R, G and B from the equation
"L=179*(0.265*R+0.67*G+0.065*B)" is not mathematically possible).

You can use a "gray" sky by assigning R=G=B=L/179, which solve your
equation.

There might be a way of using a Colored sky, but I do not know it.

Bye!

Germán

···

2014-04-15 10:10 GMT-03:00 Ehsan M.Vazifeh <[email protected]>:

Dear All,

I am calculating now the RGB Luminance for each patch of Tregenza. If lets
say I have a radiance of 200 W/(sr.m^2) then the luminance for red will be
200*0.265*179, green will be 200*0.67*179, and blue will be 200*0.065*179
?!!
or I should simply say R=G=B=200/3*179??

Thanks a lot.
Ehsan

On Mon, Apr 14, 2014 at 4:37 PM, Ehsan M.Vazifeh <[email protected]>wrote:

Thank you very much! I will try to use both methods.

Cheers,
Ehsan

On Mon, Apr 14, 2014 at 3:13 PM, John Mardaljevic < >> [email protected]> wrote:

Hi Ehsan,

Yes, that's right -- you simply scale the measured (circular patch)
luminance or radiance values by the ratio of the 'rectangular' patch solid
angle to the circular source solid angle, i.e. some factor > 1. Your sky
will of course not be continuous, but at least the total luminous output
will be realistic. See table 3-7, p70 in Chapter 3 here:

http://climate-based-daylighting.com/doku.php?id=resources:thesis

Another way is to use the measured data to create a 'brightdata'
representation of the sky, which will be continuous. How that is done is
also described in Chapter 3.

Cheers
John

John Mardaljevic PhD FSLL
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 (Direct)
Tel: +44 1509 228529 (Pam Allen, secretary)

[email protected]

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn

Personal daylighting website:
http://climate-based-daylighting.com

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

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

--
*Germán Molina L.*
Ingeniero Trainee
Hunter Douglas Chile S.A.
Celular +569 89224445

--

*Nota de Confidencialidad:* Este mensaje incluído los archivos adjuntos son
confidenciales y pueden contener informacion privilegiada protegida por
ley. Si Ud. no es el destinatario, deberia abstenerse de copiarlo,
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electronicos son susceptibles de ser cambiados, infectados o adulterados
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cambios o sus consecuencias. Usted debe estar informado que la compania
puede hacer un seguimiento de sus mensajes electronicos y su contenido,
gracias.

*Confidentiality Notice:* The information contained in this email message,
including any attachment, is confidential and is intended only for the
person or entity to which it is addressed. If you are neither the intended
recipient nor the employee or agent responsible for delivering this message
to the intended recipient, you are hereby notified that you may not review,
retransmit, convert to hard copy, copy, use or distribute this email
message or any attachments to it. If you have received this email in error,
please contact the sender immediately and delete this message from any
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A informação transmitida é confidencial e para conhecimento exclusivo do
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hi guys, been out of touch of this topic for a long time :0).

You cannot use the L from the sky scanner to get those RGB. But you can
actually put filter with known bandpass over the sky scanners to make
isolated measurements at different radiances

CW

···

On Tue, Apr 15, 2014 at 9:20 PM, CHI-German Molina <[email protected]>wrote:

Ehsan,

I understand you can't find the R,G and B values from the total luminance
values (i.e. finding R, G and B from the equation
"L=179*(0.265*R+0.67*G+0.065*B)" is not mathematically possible).

You can use a "gray" sky by assigning R=G=B=L/179, which solve your
equation.

There might be a way of using a Colored sky, but I do not know it.

Bye!

Germán

2014-04-15 10:10 GMT-03:00 Ehsan M.Vazifeh <[email protected]>:

Dear All,

I am calculating now the RGB Luminance for each patch of Tregenza. If
lets say I have a radiance of 200 W/(sr.m^2) then the luminance for red
will be 200*0.265*179, green will be 200*0.67*179, and blue will be
200*0.065*179 ?!!
or I should simply say R=G=B=200/3*179??

Thanks a lot.
Ehsan

On Mon, Apr 14, 2014 at 4:37 PM, Ehsan M.Vazifeh <[email protected]>wrote:

Thank you very much! I will try to use both methods.

Cheers,
Ehsan

On Mon, Apr 14, 2014 at 3:13 PM, John Mardaljevic < >>> [email protected]> wrote:

Hi Ehsan,

Yes, that's right -- you simply scale the measured (circular patch)
luminance or radiance values by the ratio of the 'rectangular' patch solid
angle to the circular source solid angle, i.e. some factor > 1. Your sky
will of course not be continuous, but at least the total luminous output
will be realistic. See table 3-7, p70 in Chapter 3 here:

http://climate-based-daylighting.com/doku.php?id=resources:thesis

Another way is to use the measured data to create a 'brightdata'
representation of the sky, which will be continuous. How that is done is
also described in Chapter 3.

Cheers
John

John Mardaljevic PhD FSLL
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 (Direct)
Tel: +44 1509 228529 (Pam Allen, secretary)

[email protected]

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn

Personal daylighting website:
http://climate-based-daylighting.com

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

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

--
*Germán Molina L.*
Ingeniero Trainee
Hunter Douglas Chile S.A.
Celular +569 89224445

*Nota de Confidencialidad:* Este mensaje incluído los archivos adjuntos
son confidenciales y pueden contener informacion privilegiada protegida por
ley. Si Ud. no es el destinatario, deberia abstenerse de copiarlo,
distribuirlo, divulgarlo o usar la informacion contenida. Por favor, avise
inmediatamente al emisor y borre este mensaje de su sistema. Los mensajes
electronicos son susceptibles de ser cambiados, infectados o adulterados
sin autorizacion. No asumimos responsabilidad alguna por ninguna clase de
cambios o sus consecuencias. Usted debe estar informado que la compania
puede hacer un seguimiento de sus mensajes electronicos y su contenido,
gracias.

*Confidentiality Notice:* The information contained in this email
message, including any attachment, is confidential and is intended only for
the person or entity to which it is addressed. If you are neither the
intended recipient nor the employee or agent responsible for delivering
this message to the intended recipient, you are hereby notified that you
may not review, retransmit, convert to hard copy, copy, use or distribute
this email message or any attachments to it. If you have received this
email in error, please contact the sender immediately and delete this
message from any computer or other data bank, Thank you.

A informação transmitida é confidencial e para conhecimento exclusivo do
destinatário. Sua utilização, não autorizada, constitui crime passível de
prisão. Todas as precauções possíveis foram tomadas para garantir que este
e-mail não contenha vírus. Uma vez que nossa empresa não pode assumir
responsabilidade por nenhuma perda ou dano causado por este e-mail ou de
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antivírus antes de qualquer uso.

_______________________________________________
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Hi Chang,

As I understand you correctly, you mean to filter each color, therefore, I
need three sky scanner? :s

Cheers,
Ehsan

···

On Tue, Apr 15, 2014 at 3:25 PM, chang cw <[email protected]> wrote:

hi guys, been out of touch of this topic for a long time :0).

You cannot use the L from the sky scanner to get those RGB. But you can
actually put filter with known bandpass over the sky scanners to make
isolated measurements at different radiances

CW

On Tue, Apr 15, 2014 at 9:20 PM, CHI-German Molina <[email protected]>wrote:

Ehsan,

I understand you can't find the R,G and B values from the total luminance
values (i.e. finding R, G and B from the equation
"L=179*(0.265*R+0.67*G+0.065*B)" is not mathematically possible).

You can use a "gray" sky by assigning R=G=B=L/179, which solve your
equation.

There might be a way of using a Colored sky, but I do not know it.

Bye!

Germán

2014-04-15 10:10 GMT-03:00 Ehsan M.Vazifeh <[email protected]>:

Dear All,

I am calculating now the RGB Luminance for each patch of Tregenza. If
lets say I have a radiance of 200 W/(sr.m^2) then the luminance for red
will be 200*0.265*179, green will be 200*0.67*179, and blue will be
200*0.065*179 ?!!
or I should simply say R=G=B=200/3*179??

Thanks a lot.
Ehsan

On Mon, Apr 14, 2014 at 4:37 PM, Ehsan M.Vazifeh <[email protected]>wrote:

Thank you very much! I will try to use both methods.

Cheers,
Ehsan

On Mon, Apr 14, 2014 at 3:13 PM, John Mardaljevic < >>>> [email protected]> wrote:

Hi Ehsan,

Yes, that's right -- you simply scale the measured (circular patch)
luminance or radiance values by the ratio of the 'rectangular' patch solid
angle to the circular source solid angle, i.e. some factor > 1. Your sky
will of course not be continuous, but at least the total luminous output
will be realistic. See table 3-7, p70 in Chapter 3 here:

http://climate-based-daylighting.com/doku.php?id=resources:thesis

Another way is to use the measured data to create a 'brightdata'
representation of the sky, which will be continuous. How that is done is
also described in Chapter 3.

Cheers
John

John Mardaljevic PhD FSLL
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 (Direct)
Tel: +44 1509 228529 (Pam Allen, secretary)

[email protected]

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn

Personal daylighting website:
http://climate-based-daylighting.com

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

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

--
*Germán Molina L.*
Ingeniero Trainee
Hunter Douglas Chile S.A.
Celular +569 89224445

*Nota de Confidencialidad:* Este mensaje incluído los archivos adjuntos
son confidenciales y pueden contener informacion privilegiada protegida por
ley. Si Ud. no es el destinatario, deberia abstenerse de copiarlo,
distribuirlo, divulgarlo o usar la informacion contenida. Por favor, avise
inmediatamente al emisor y borre este mensaje de su sistema. Los mensajes
electronicos son susceptibles de ser cambiados, infectados o adulterados
sin autorizacion. No asumimos responsabilidad alguna por ninguna clase de
cambios o sus consecuencias. Usted debe estar informado que la compania
puede hacer un seguimiento de sus mensajes electronicos y su contenido,
gracias.

*Confidentiality Notice:* The information contained in this email
message, including any attachment, is confidential and is intended only for
the person or entity to which it is addressed. If you are neither the
intended recipient nor the employee or agent responsible for delivering
this message to the intended recipient, you are hereby notified that you
may not review, retransmit, convert to hard copy, copy, use or distribute
this email message or any attachments to it. If you have received this
email in error, please contact the sender immediately and delete this
message from any computer or other data bank, Thank you.

A informação transmitida é confidencial e para conhecimento exclusivo do
destinatário. Sua utilização, não autorizada, constitui crime passível de
prisão. Todas as precauções possíveis foram tomadas para garantir que este
e-mail não contenha vírus. Uma vez que nossa empresa não pode assumir
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_______________________________________________
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http://www.radiance-online.org/mailman/listinfo/radiance-general

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

--
Dipl. Ing. Ehsan, M. Vazifeh
Project Assistant
Department of Building Physics and Building Ecology
Vienna University of Technology
Karlsplatz 13, A-1040 Vienna, Austria
Tel +43 1 58801 27003
Fax +43 1 58801 27093
[email protected]
www.bpi.tuwien.ac.at

Yes or you can make measurements at 1 min interval.

If you are willing to try new stuff check out sun photometers at
http://aeronet.gsfc.nasa.gov

though the do not cover the whole sky dome, i think with measurements that
they make, you can easily construct the scattering properties of the
atmosphere from the phase function and that cover quite a few discrete
wavelengths.

Cheers

CW

···

On Tue, Apr 15, 2014 at 9:53 PM, Ehsan M.Vazifeh <[email protected]>wrote:

Hi Chang,

As I understand you correctly, you mean to filter each color, therefore, I
need three sky scanner? :s

Cheers,
Ehsan

On Tue, Apr 15, 2014 at 3:25 PM, chang cw <[email protected]> wrote:

hi guys, been out of touch of this topic for a long time :0).

You cannot use the L from the sky scanner to get those RGB. But you can
actually put filter with known bandpass over the sky scanners to make
isolated measurements at different radiances

CW

On Tue, Apr 15, 2014 at 9:20 PM, CHI-German Molina <[email protected]>wrote:

Ehsan,

I understand you can't find the R,G and B values from the total
luminance values (i.e. finding R, G and B from the equation
"L=179*(0.265*R+0.67*G+0.065*B)" is not mathematically possible).

You can use a "gray" sky by assigning R=G=B=L/179, which solve your
equation.

There might be a way of using a Colored sky, but I do not know it.

Bye!

Germán

2014-04-15 10:10 GMT-03:00 Ehsan M.Vazifeh <[email protected]>:

Dear All,

I am calculating now the RGB Luminance for each patch of Tregenza. If
lets say I have a radiance of 200 W/(sr.m^2) then the luminance for red
will be 200*0.265*179, green will be 200*0.67*179, and blue will be
200*0.065*179 ?!!
or I should simply say R=G=B=200/3*179??

Thanks a lot.
Ehsan

On Mon, Apr 14, 2014 at 4:37 PM, Ehsan M.Vazifeh <[email protected]>wrote:

Thank you very much! I will try to use both methods.

Cheers,
Ehsan

On Mon, Apr 14, 2014 at 3:13 PM, John Mardaljevic < >>>>> [email protected]> wrote:

Hi Ehsan,

Yes, that's right -- you simply scale the measured (circular patch)
luminance or radiance values by the ratio of the 'rectangular' patch solid
angle to the circular source solid angle, i.e. some factor > 1. Your sky
will of course not be continuous, but at least the total luminous output
will be realistic. See table 3-7, p70 in Chapter 3 here:

http://climate-based-daylighting.com/doku.php?id=resources:thesis

Another way is to use the measured data to create a 'brightdata'
representation of the sky, which will be continuous. How that is done is
also described in Chapter 3.

Cheers
John

John Mardaljevic PhD FSLL
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 (Direct)
Tel: +44 1509 228529 (Pam Allen, secretary)

[email protected]

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn

Personal daylighting website:
http://climate-based-daylighting.com

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

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

--
*Germán Molina L.*
Ingeniero Trainee
Hunter Douglas Chile S.A.
Celular +569 89224445

*Nota de Confidencialidad:* Este mensaje incluído los archivos adjuntos
son confidenciales y pueden contener informacion privilegiada protegida por
ley. Si Ud. no es el destinatario, deberia abstenerse de copiarlo,
distribuirlo, divulgarlo o usar la informacion contenida. Por favor, avise
inmediatamente al emisor y borre este mensaje de su sistema. Los mensajes
electronicos son susceptibles de ser cambiados, infectados o adulterados
sin autorizacion. No asumimos responsabilidad alguna por ninguna clase de
cambios o sus consecuencias. Usted debe estar informado que la compania
puede hacer un seguimiento de sus mensajes electronicos y su contenido,
gracias.

*Confidentiality Notice:* The information contained in this email
message, including any attachment, is confidential and is intended only for
the person or entity to which it is addressed. If you are neither the
intended recipient nor the employee or agent responsible for delivering
this message to the intended recipient, you are hereby notified that you
may not review, retransmit, convert to hard copy, copy, use or distribute
this email message or any attachments to it. If you have received this
email in error, please contact the sender immediately and delete this
message from any computer or other data bank, Thank you.

A informação transmitida é confidencial e para conhecimento exclusivo do
destinatário. Sua utilização, não autorizada, constitui crime passível de
prisão. Todas as precauções possíveis foram tomadas para garantir que este
e-mail não contenha vírus. Uma vez que nossa empresa não pode assumir
responsabilidade por nenhuma perda ou dano causado por este e-mail ou de
seus anexos, recomendamos que o destinatário utilize seus procedimentos de
antivírus antes de qualquer uso.

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

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

--
Dipl. Ing. Ehsan, M. Vazifeh
Project Assistant
Department of Building Physics and Building Ecology
Vienna University of Technology
Karlsplatz 13, A-1040 Vienna, Austria
Tel +43 1 58801 27003
Fax +43 1 58801 27093
[email protected]
www.bpi.tuwien.ac.at

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

I am using MS sky-scanner, it takes about 4.5 minutes to sky once the whole
sky dome. therefore, we are recording data in 15 min intervals.

Cheers,
Ehsan

···

On Tue, Apr 15, 2014 at 4:00 PM, chang cw <[email protected]> wrote:

Yes or you can make measurements at 1 min interval.

If you are willing to try new stuff check out sun photometers at
http://aeronet.gsfc.nasa.gov

though the do not cover the whole sky dome, i think with measurements that
they make, you can easily construct the scattering properties of the
atmosphere from the phase function and that cover quite a few discrete
wavelengths.

Cheers

CW

On Tue, Apr 15, 2014 at 9:53 PM, Ehsan M.Vazifeh <[email protected]>wrote:

Hi Chang,

As I understand you correctly, you mean to filter each color, therefore,
I need three sky scanner? :s

Cheers,
Ehsan

On Tue, Apr 15, 2014 at 3:25 PM, chang cw <[email protected]> wrote:

hi guys, been out of touch of this topic for a long time :0).

You cannot use the L from the sky scanner to get those RGB. But you can
actually put filter with known bandpass over the sky scanners to make
isolated measurements at different radiances

CW

On Tue, Apr 15, 2014 at 9:20 PM, CHI-German Molina <[email protected]>wrote:

Ehsan,

I understand you can't find the R,G and B values from the total
luminance values (i.e. finding R, G and B from the equation
"L=179*(0.265*R+0.67*G+0.065*B)" is not mathematically possible).

You can use a "gray" sky by assigning R=G=B=L/179, which solve your
equation.

There might be a way of using a Colored sky, but I do not know it.

Bye!

Germán

2014-04-15 10:10 GMT-03:00 Ehsan M.Vazifeh <[email protected]>:

Dear All,

I am calculating now the RGB Luminance for each patch of Tregenza. If
lets say I have a radiance of 200 W/(sr.m^2) then the luminance for red
will be 200*0.265*179, green will be 200*0.67*179, and blue will be
200*0.065*179 ?!!
or I should simply say R=G=B=200/3*179??

Thanks a lot.
Ehsan

On Mon, Apr 14, 2014 at 4:37 PM, Ehsan M.Vazifeh <[email protected] >>>>> > wrote:

Thank you very much! I will try to use both methods.

Cheers,
Ehsan

On Mon, Apr 14, 2014 at 3:13 PM, John Mardaljevic < >>>>>> [email protected]> wrote:

Hi Ehsan,

Yes, that's right -- you simply scale the measured (circular patch)
luminance or radiance values by the ratio of the 'rectangular' patch solid
angle to the circular source solid angle, i.e. some factor > 1. Your sky
will of course not be continuous, but at least the total luminous output
will be realistic. See table 3-7, p70 in Chapter 3 here:

http://climate-based-daylighting.com/doku.php?id=resources:thesis

Another way is to use the measured data to create a 'brightdata'
representation of the sky, which will be continuous. How that is done is
also described in Chapter 3.

Cheers
John

John Mardaljevic PhD FSLL
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 (Direct)
Tel: +44 1509 228529 (Pam Allen, secretary)

[email protected]

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn

Personal daylighting website:
http://climate-based-daylighting.com

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

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

--
*Germán Molina L.*
Ingeniero Trainee
Hunter Douglas Chile S.A.
Celular +569 89224445

*Nota de Confidencialidad:* Este mensaje incluído los archivos
adjuntos son confidenciales y pueden contener informacion privilegiada
protegida por ley. Si Ud. no es el destinatario, deberia abstenerse de
copiarlo, distribuirlo, divulgarlo o usar la informacion contenida. Por
favor, avise inmediatamente al emisor y borre este mensaje de su sistema.
Los mensajes electronicos son susceptibles de ser cambiados, infectados o
adulterados sin autorizacion. No asumimos responsabilidad alguna por
ninguna clase de cambios o sus consecuencias. Usted debe estar informado
que la compania puede hacer un seguimiento de sus mensajes electronicos y
su contenido, gracias.

*Confidentiality Notice:* The information contained in this email
message, including any attachment, is confidential and is intended only for
the person or entity to which it is addressed. If you are neither the
intended recipient nor the employee or agent responsible for delivering
this message to the intended recipient, you are hereby notified that you
may not review, retransmit, convert to hard copy, copy, use or distribute
this email message or any attachments to it. If you have received this
email in error, please contact the sender immediately and delete this
message from any computer or other data bank, Thank you.

A informação transmitida é confidencial e para conhecimento exclusivo
do destinatário. Sua utilização, não autorizada, constitui crime passível
de prisão. Todas as precauções possíveis foram tomadas para garantir que
este e-mail não contenha vírus. Uma vez que nossa empresa não pode assumir
responsabilidade por nenhuma perda ou dano causado por este e-mail ou de
seus anexos, recomendamos que o destinatário utilize seus procedimentos de
antivírus antes de qualquer uso.

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

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

--
Dipl. Ing. Ehsan, M. Vazifeh
Project Assistant
Department of Building Physics and Building Ecology
Vienna University of Technology
Karlsplatz 13, A-1040 Vienna, Austria
Tel +43 1 58801 27003
Fax +43 1 58801 27093
[email protected]
www.bpi.tuwien.ac.at

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

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

--
Dipl. Ing. Ehsan, M. Vazifeh
Project Assistant
Department of Building Physics and Building Ecology
Vienna University of Technology
Karlsplatz 13, A-1040 Vienna, Austria
Tel +43 1 58801 27003
Fax +43 1 58801 27093
[email protected]
www.bpi.tuwien.ac.at