pytroll
Issues about fog composites
I would like to ask what is the physical significance of the results generated by ahi/hsd's fog composites. The 3D matrix does not seem to confirm the exact distribution of this fog. Is there something inappropriate in our approach？
@augustou18 Could you please provide the code you are running to generate the data/image you're looking at and include the exact composite name you are loading?
@djhoese Hi, djhoese. The composite output fog is a three-dimensional(3 bands) matrix, what is its physical meaning?
What fog composite are you talking about? Please answer my questions above. My understanding is you are providing Satpy data as AHI HSD files and generating a "fog" composite. Could you please show me the code you are running to do this?
@djhoese Hi, djhoese. I’m using AHI HSD files and generating a "fog" composite too. I get a "fog" image using "scn.load(['fog'])", Could you please tell me what the colors on the picture represent? Thanks.
@ZitaTan I think the fog composite in satpy is the 24h microphysics, which you can read more about here https://resources.eumetrain.org/rgb_quick_guides/quick_guides/24MicroRGB.pdf
Note that there is always a chance our recipe was implemented poorly so please let us know if something looks off. One thing I noticed is that the AHI configuration specifically has difference channels used for the 10.8um in the two differences. See:
https://github.com/pytroll/satpy/blob/394add5602e3eb052e24febd79839bf32254d8b5/satpy/etc/composites/ahi.yaml#L123-L135
Instead of using B13 for both differences, it uses (B15 - B13) for red and (B14 - B11) for green (instead of B13 - B11). I think this is expected for AHI given the goals of the composite and the properties of those bands. Night microphysics is configured similarly. I'm not a scientist, but this is what I remember from past discussions.
Closing this as the conversation pointed the issue creator to the eumetrain rgb quick guide for this fog composite.
