Difference in using MODIS vs. SeaWIFS satellite imagery

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lvibert
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Difference in using MODIS vs. SeaWIFS satellite imagery

by lvibert » Wed Jul 17, 2019 10:17 am America/New_York

Hello,
I am using MODIS-AQUA satellite imagery for assessing Sea-Ice Concentration and Chlorophyl-a concentration on the Antarctic Southern Ocean, and found afterward that SeaWiFS was more commonly used in the literature.
Is there big differences by using one instead of the other? What consequence can it have on my data and on my work?
Thanks for your help
L.

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OB.DAAC - SeanBailey
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Difference in using MODIS vs. SeaWIFS satellite imagery

by OB.DAAC - SeanBailey » Wed Jul 17, 2019 3:00 pm America/New_York

SeaWiFS was a dedicated ocean color instrument.  A feature it had that is lacking with MODIS was that the instrument tilted to minimize the impact of sun glint.
The MODIS instruments on the Terra and Aqua platforms do not tilt and thus are subject to more glint contamination.  That said, glint is less of a problem in the Southern Ocean than in the Equatorial Pacific :wink:

There are other differences between the sensors( e.g. MODIS lacks the 510nm channel that SeaWIFS has, but MODIS has a 531nm channel that SeaWiFS doesn't, MODIS has SWIR channels.  MODIS is a 12bit instrument, SeaWiFS is effectively 10bit)  But the biggest difference today is that SeaWiFS, after 13 years in orbit<died in December of 2010 while MODIS continues to collect data.

We do our best to ensure the instruments produce data as consistently as possible.  There is sufficient overlap between the two for you to compare results.  You should make the comparison and decide for yourself which sensor to use....or use them both :smile:

Sean

lvibert
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Joined: Wed Jul 17, 2019 10:12 am America/New_York

Difference in using MODIS vs. SeaWIFS satellite imagery

by lvibert » Thu Jul 18, 2019 7:53 am America/New_York

Hi
great thanks for the answer !
Then, if I use MODIS-A data, will my results be comparable with results from studies using SeaWIFS data? Or should I apply kind of a correction"?

L.

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Difference in using MODIS vs. SeaWIFS satellite imagery

by OB.DAAC - SeanBailey » Thu Jul 18, 2019 8:46 am America/New_York

Yes, they should be reasonably comparable.  BTW, the global products from SeaWiFS are at ~9.2km resolution while MODIS is ~4.6km resolution, so another difference to keep in mind.
Since there is overlap between the two missions, I'd suggest running your analysis on both at least for a portion of the time series. 

Sean

lvibert
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Joined: Wed Jul 17, 2019 10:12 am America/New_York

Difference in using MODIS vs. SeaWIFS satellite imagery

by lvibert » Thu Jul 18, 2019 9:09 am America/New_York

Yes, I already noticed the difference in resolution, this is one of the reason I prefered MODIS
Thank you very much for the help =)
L.

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