## How to average images with clouds and ignore these cloud pixels?

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OB SeaDAS - xuanyang02
Subject Matter Expert
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Joined: Tue Feb 09, 2021 5:42 pm America/New_York
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### Re: How to average images with clouds and ignore these cloud pixels?

Thanks George for pointing out the difference between the average of geophysical parameters and the math average.

Hope I get it right this time --

((chlor_a_M >= 0.0 ? chlor_a_M : 0) +(
chlor_a_D0 >= 0.0 ? chlor_a_D0 : 0) +
(chlor_a_D1 >= 0.0 ? chlor_a_D1 : 0)) /
(((chlor_a_M >= 0.0 ? 1 : 0) +
(chlor_a_D0 >= 0.0 ? 1 : 0) +
(chlor_a_D1 >= 0.0 ? 1 : 0))

If you do Math Band after collocation.

((\$1.chlor_a >= 0.0 ? \$1.chlor_a : 0) +
(\$2.chlor_a >= 0.0 ? \$2.chlor_a : 0) +
(\$3.chlor_a >= 0.0 ? \$3.chlor_a : 0)) /
((\$1.chlor_a >= 0.0 ? 1 : 0) +
(\$2.chlor_a >= 0.0 ? 1 : 0) +
(\$3.chlor_a >= 0.0 ? 1 : 0))

if you do Math Band directly on the three bands.

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cassandra21
Posts: 22
Joined: Thu Jan 19, 2023 11:41 am America/New_York
Answers: 0

### Re: How to average images with clouds and ignore these cloud pixels?

Hello! I'm writting to let you know that it worked!

Thank you so much for your help :)

cassandra21
Posts: 22
Joined: Thu Jan 19, 2023 11:41 am America/New_York
Answers: 0

### Re: How to average images with clouds and ignore these cloud pixels?

Dear xuanyang02, I applied this algorithm in my thesis work. I would like to cite you for using this algorithm, so I would appreciate if you could tell me how to cite you properly in my Master thesis. Thank you so much :)

OB SeaDAS - xuanyang02
Subject Matter Expert
Posts: 664
Joined: Tue Feb 09, 2021 5:42 pm America/New_York
Answers: 1
Been thanked: 2 times

### Re: How to average images with clouds and ignore these cloud pixels?

It's always nice to be acknowledged

Here is the link to "how to cite" -- https://oceancolor.gsfc.nasa.gov/resources/how-to-cite/