1

So I'm running the area solar radiation tool using the time configuration and other parameters as seen here:

enter image description here

By selecting the "Create outputs for each interval" checkbox, the global radiation raster that is output contains 12 bands. My question is:
How do I know which bands correspond to which hours of the day?

I've browsed ESRI's geonet forum on the topic but couldn't find anything helpful

3
  • We have several questions on extracting bands, such as gis.stackexchange.com/questions/63689 or gis.stackexchange.com/questions/11150 or gis.stackexchange.com/questions/85895 I'm not familiar with the tool, but I would expect the bands to be ordered chronologically. Based on the help, I do find it odd you're getting 12 bands for a 24 hour period with a 1 hour interval (I would expect 24), unless it's only producing one band for all hours with no exposure.
    – Chris W
    Mar 17 '15 at 20:49
  • As per the Tour there should be only one question asked per question.
    – PolyGeo
    Sep 27 '16 at 5:11
  • 1
    This is a clear and pertinent question. Users focused in the second part of the question which has been answered multiple times as @Chris W points out. However no one has addressed the main mystery that is still present in current versions of ArcGIS desktop and Pro. When creating multiple outputs for a day sometimes you cannot know what bands are from each time step since I'm guessing the tool skips all hours with no radiation. I just have encountered the same issue running a whole day with 0.5 hour interval. It outputs a multiband raster of 30 bands that are just named "Band_1" to "Band_30"
    – Albert
    Oct 15 '19 at 7:04
2

You can add separate bands to map by double clicking on raster in Add data window or by clicking on the plus button next to the raster in arc catalogue and dragging separate bands to the map. You can then export them into separate files. The bands are also numbered so in my opinion each number should correspond to each interval.

0

This issue hasn't been addressed in any ArcGIS update and is still present in the current versions of ArcGIS Pro and Desktop.

When you check the option "create outputs for each interval" within a day, the tool outputs a multi-band raster of n bands. In my case, using the following settings for my latitude I get 29 bands.

enter image description here

The output bands are just named Band_1 to Band_29 and there is no way to know the time of each band, one can only guess.

What I do is I check on a solar web calculator the sunrise and sunset times for my location in that particular day. You can calculate this in this website, for instance.

In my case the radiation for that day goes as follows:

  • Astronomical twilight: 4:53 to 5:36
  • Nautical twilight: 5:36 to 06:15
  • Civil twilight: 6:15 to 6:46
  • Sunrise: 6:46
  • Sunset: 21:08
  • Civil twilight: 21:08 to 21:39
  • Nautical twilight: 21:39 to 22:17
  • Astronomical twilight: 22:17 to 23:00

It would be reasonable to have more bands in the diffuse and global radiation outputs since there is enough radiation when the sun is still below the horizon line during the civil twilight "solar illumination suffices for the human eye to clearly distinguish terrestrial objects". I would expect then to have some measure in the diffuse radiation output.

However, accounting the daylenght + civil twilight would be 15 hours and 24 minutes which would result in 30-31 bands. Daylenght is 14 hours 22 minutes which using a half-hour interval is consistent with the 29 resulting bands. Therefore, since sunrise is at 6:46, I assign the first band at 7:00 and the following bands at 7:30, 8:00 and so on. The first band could also start at 6:46 or even at 6:30 so this is still just a guess.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.