Verify that BSDF can be stored according to opticalData.json

[christoph-maurer]

@bbuenoun 's third remark in https://github.com/ise621/building-envelope-data/issues/42#issuecomment-700067196 was:

"3. We need an additional property: results/properties/BSDF. I believe the BSDF values in the output file of pg2 are consine corrected. @HelenRoseWilson can you please confirm? we need to check if the BSDF values in Klems format are also cosine corrected."

My thoughts with the current schema were: If BSDF is exchanged in the form of a resource, for example as file, the format can be defined by "reference". If BSDF is exchanged in "intermediate form", then "bidirectionalTransmittanceDistributionFunction" and "bidirectionalReflectanceDistributionFunction" can be defined including cosine. If BSDF is exchanged in "verbose form", it has to be calculated without cosine. We need to reduce the number of equivalent representations of the same data as much as possible to enable a good search for the data. Therefore, conversion of data is sometimes needed.

@HelenRoseWilson and @bbuenoun , is it ok for you like this?

[HelenRoseWilson]

Dear Christoph, to my understanding, there are two different quantities which differ in value by cosine (theta). According to pab, "The BSDF*cos value is called DSF (differential scattering function) by the ASTM E2387 standard." The output files from pgII contain either BSDF or DSF values in the third column of data and this third column is identified by the corresponding label. Best regards, Helen Rose.

Am 03.11.2020 um 10:28 schrieb Christoph Maurer:

@bbuenoun https://github.com/bbuenoun 's third remark in #42 (comment) https://github.com/ise621/building-envelope-data/issues/42#issuecomment-700067196 was:

"3. We need an additional property: results/properties/BSDF. I believe the BSDF values in the output file of pg2 are consine corrected. @HelenRoseWilson https://github.com/HelenRoseWilson can you please confirm? we need to check if the BSDF values in Klems format are also cosine corrected."

My thoughts with the current schema were: If BSDF is exchanged in the form of a resource, for example as file, the format can be defined by "reference". If BSDF is exchanged in "intermediate form", then "bidirectionalTransmittanceDistributionFunction" https://github.com/ise621/building-envelope-data/blob/6af9034b0964133386100d484d7bd9fdcf8e5afb/schemas/opticalData.json#L652 and "bidirectionalReflectanceDistributionFunction" can be defined including cosine. If BSDF is exchanged in "verbose form", it has to be calculated without cosine. We need to reduce the number of equivalent representations of the same data as much as possible to enable a good search for the data. Therefore, conversion of data is sometimes needed.

@HelenRoseWilson https://github.com/HelenRoseWilson and @bbuenoun https://github.com/bbuenoun , is it ok for you like this?

— You are receiving this because you were assigned. Reply to this email directly, view it on GitHub https://github.com/ise621/building-envelope-data/issues/142, or unsubscribe https://github.com/notifications/unsubscribe-auth/AQVJLYRAS7KPX3QKQR7RKU3SN7ELRANCNFSM4TIP5ZDQ.

-- Dr Helen Rose Wilson Solar Building Envelopes Energy-Efficient Buildings Fraunhofer Institute for Solar Energy Systems Heidenhofstr. 2, 79110 Freiburg i. Br., Germany Phone (bus.): +49 761 4588-5149 Phone (priv.): +49 761 441247 helen.rose.wilson@ise.fraunhofer.de

Web: www.ise.fraunhofer.de https://www.ise.fraunhofer.de

[christoph-maurer]

We have to avoid to many redundant ways to store the same information. I would therefore stick to the current schema. BSDF with and without cosine can be converted back and forth. Ok, @HelenRoseWilson and @bbuenoun ?

[HelenRoseWilson]

I agree that we do not need redundant ways to store the same information.  However, we should not talk about "BSDF with and without cosine".  There is a single definition of BSDF given in ASTM E2387-05 "Standard Practive for Goniometric Optical Scatter Measurements", so we can refer to that standard and foresee only "BSDF" in the schema. (The ASTM standard also defines DSF = BSDF * cos(theta) but we do not need to add this further information to the schema.) Best regards, Helen Rose.

Am 10.11.2020 um 12:34 schrieb Christoph Maurer:

We have to avoid to many redundant ways to store the same information. I would therefore stick to the current schema. BSDF with and without cosine can be converted back and forth. Ok, @HelenRoseWilson https://github.com/HelenRoseWilson and @bbuenoun https://github.com/bbuenoun ?

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/ise621/building-envelope-data/issues/142#issuecomment-724645742, or unsubscribe https://github.com/notifications/unsubscribe-auth/AQVJLYSEQOEWRVUYO3P2VHDSPEQMJANCNFSM4TIP5ZDQ.

-- Dr Helen Rose Wilson Solar Building Envelopes Energy-Efficient Buildings Fraunhofer Institute for Solar Energy Systems Heidenhofstr. 2, 79110 Freiburg i. Br., Germany Phone (bus.): +49 761 4588-5149 Phone (priv.): +49 761 441247 helen.rose.wilson@ise.fraunhofer.de

Web: www.ise.fraunhofer.de https://www.ise.fraunhofer.de

[christoph-maurer]

I agree. You, too, @bbuenoun ?

[bbuenoun]

Yes, I agree.