## How interpolate SMAP salinity fro L2 to L3?

### How interpolate SMAP salinity fro L2 to L3?

Hi!
I am curious about L3 interpolation method.
The document(*) refers that Gaussian weighting is used, how consider it about time?
And does 8-day mean that it includes the past senven days as of now?
Then I wonder if the 8-day data were just averaged to interpolate missing pixel of today.
I would appreciate it if you recommend a document that explains this in detail.
Thank you!
*SMAP Salinity and Wind Speed Data User's Guide Version 4.3
enjang

Posts: 2
Joined: Thu Dec 03, 2020 1:52 am

### Re: How interpolate SMAP salinity fro L2 to L3?

Hi,
Thanks for the inquiry and support. You may check the SMAP ATBD in the following link: https://podaac-tools.jpl.nasa.gov/drive ... tation.pdf.

And here is the brief summary for the algorithm from the document:

"For an 8-day running average that is centered on a given day of the year (DOY) we average all valid observations within +/- 3.5 days of said DOY. For example, the L3 file for January 15 is created by averaging L2 observations that fall between 12UTC January 11 and 12UTC January 19. The reason for providing 8-day averages rather than weekly averages is that SMAP has an exact 8-day repeat cycle.

Hope this helps.

Regards,

PODAAC DE
yiboj

Posts: 130
Joined: Mon Mar 30, 2015 11:22 am

### Re: How interpolate SMAP salinity fro L2 to L3?

I understand as you told me, but recently I have a different question.

You recommended 'NASA/RSS SMAP Salinity: Version 4.0 Validated Release' document.

I am using JPL SMAP L2B SSS V5.0 product, but this document is about RSS outputs.
And there is no mention of Gaussian weighting in the L3 processing in this document ('NASA/RSS SMAP Salinity: Version 4.0 Validated Release').

Are RSS and JPL's L3 algorithms the same?
I would appreciate it if you recommend a document that explains the JPL SMAP L3 interpolation method in detail.

Thank you!

Best Regards,
Eunna Jang
enjang

Posts: 2
Joined: Thu Dec 03, 2020 1:52 am

Hi Eunna,