The value is nan for chlor_a from MODIS
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The value is nan for chlor_a from MODIS
Dear all,
I have run l2gen for MODIS data. I want to extract chlor_a. But the result value is nan. Why ?
While for other date MODIS data, the data is not nan.
The MODIS data is in : https://1drv.ms/u/s!AjXAWS5maHffhyu6DmUAGwxoJaJq?e=eUzkBf
I put the result of chlor in that link.
Thank you.
I have run l2gen for MODIS data. I want to extract chlor_a. But the result value is nan. Why ?
While for other date MODIS data, the data is not nan.
The MODIS data is in : https://1drv.ms/u/s!AjXAWS5maHffhyu6DmUAGwxoJaJq?e=eUzkBf
I put the result of chlor in that link.
Thank you.
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The value is nan for chlor_a from MODIS
Looks like this is a night time file. All pixels PRODFAIL and HISOLZEN. L2gen flagged it as :day_night_flag = "Night"
can't get chl at night.
don
can't get chl at night.
don
The value is nan for chlor_a from MODIS
l2gen
output includes a summary of flags:[...]
Flag #13: HISOLZEN 5524320 86.4407
[...]
Flag #31: PRODFAIL 6390880 100.0000
The
HISOLZEN
flag indicates the sun is close to the horizon, so you should not expect useful results.
You can also see the percentages in the NetCDF metadata:
$ ncdump -h chla
[...]
group: flag_percentages {
// group attributes:
:ATMFAIL = 0.f ;
:LAND = 26.62129f ;
:PRODWARN = 0.f ;
:HIGLINT = 0.f ;
:HILT = 0.f ;
:HISATZEN = 5.927666f ;
:COASTZ = 4.799761f ;
:SPARE = 0.f ;
:STRAYLIGHT = 0.f ;
:CLDICE = 0.f ;
:COCCOLITH = 0.f ;
:TURBIDW = 0.f ;
:HISOLZEN = 86.44067f ;
:LOWLW = 0.f ;
:CHLFAIL = 0.f ;
:NAVWARN = 13.34746f ;
:ABSAER = 0.f ;
:MAXAERITER = 0.f ;
:MODGLINT = 0.6738195f ;
:CHLWARN = 0.f ;
:ATMWARN = 0.f ;
:SEAICE = 0.f ;
:NAVFAIL = 13.55932f ;
:FILTER = 0.f ;
:BOWTIEDEL = 0.f ;
:HIPOL = 0.f ;
:PRODFAIL = 100.f ;
} // group flag_percentages
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- Posts: 15
- Joined: Sun Dec 27, 2020 10:57 pm America/New_York
The value is nan for chlor_a from MODIS
oh I see.
I did't see the time of acquisition.
Thank you for your information
I did't see the time of acquisition.
Thank you for your information