topic Re: Area Solar radiation light source in ArcGIS Spatial Analyst Questions

Area Solar radiation light source

Pål_Herman_Sund — Tue, 29 Aug 2023 11:46:06 GMT

Hi, a client ask a question to which I have no answer and hoping for some help.

They are using the "area solar radiation" tool and comparing the outputs with results from tools like Sarah2 and Meteonorm 8.1 - and in general the result from these give higher radiation.

to the question: what is the source of insolation? Not specified in for this tool

Re: Area Solar radiation light source

AyanPalit — Tue, 29 Aug 2023 13:00:39 GMT

@Pål_Herman_Sund Insolation is getting estimated in the GP tool Area Solar Radiation using input parameters like Elevation, Latitude location, Sky exposure, Time span

Advanced parameters can be added like:

Re: Area Solar radiation light source

RyanDeBruyn — Tue, 29 Aug 2023 13:05:53 GMT

Hi there, those sources you mention look to be from satellite data, where as the the solar radiation analysis tools calculate insolation from the input surface or for a specific locations, based on methods from the hemispherical viewshed algorithm.

Here are some related help topics for the tools. Hope this helps.

How solar radiation is calculated

Understanding solar radiation analysis

-Ryan

Re: Area Solar radiation light source

Pål_Herman_Sund — Tue, 29 Aug 2023 13:22:37 GMT

Thanks guys, I am way off my competences here, I guess the question is about the source of light itself if I understand correct. Tell me if I am way off (no offence taken 🙂 ) - and as you both are at ESRI if you are able to assist in a supportcase. Thanks, pH

Re: Area Solar radiation light source

RyanDeBruyn — Tue, 29 Aug 2023 14:17:16 GMT

@Pål_Herman_Sund

The source or radiation (energy) is calculated from the sun and the sun angles, for the time specified, based on the location of each cell in the input surface. Along with the sky/sun map (how the sun seemingly moves across the sky) and the visibility (is the location shaded by a mountain for part of the day) the tool calculates the the total radiation per unit area.

Total radiation is composed of,

Direct Radiation (the radiation which comes directly from the sun)
Diffused Radiation (the radiation which is diffused by the sky, layers of atmosphere and other surroundings)

This is highlighted in the conceptual documentation for the tools.

Let me know if I am missing something in your question.

Regards,

-Ryan

Re: Area Solar radiation light source

Pål_Herman_Sund — Tue, 29 Aug 2023 19:06:16 GMT

Thanks @RyanDeBruyn That seems like an answer close to what I believe we are looking for. I will forward and hopefully an acceptable answer. I will update after discussing with my client. Thanks also @AyanPalit for the contributions 🙂 pH