UNITS of sentinel 3

I have one question regarding units of sentinel 3reflectance units values
my CHL observations are in microgram/liter and the sentinel 3 reflectance are in W.m-2. sr-1 Micro meter-1 so how to compare here
like individual band comparison and band ratio comparison
thanks

Before you can compare your insitu chl observations you need to derive the chl concentration for the leve-1 scene. To do this you can use for example the C2RCC which comes with the S3TBX.
But there are also other methodologies.
You can also use the official Level-2 Water products. They contain already variables for chl.

ok sir.
sir after mosaicking im trying to apply c2rcc but im facing this error.
plz help me

You need to do the C2RCC processing before the mosaicking.

okay sir. i will try

Here i m attaching before after mosaicking images. is there any way i can get as well as before mosaicking image picture clarity after mosaicking


Sorry, I don’t understand your question. Can you rephrase it?

I’ve attached before and after mosaicking screen shots.
if we observe first image is better than 2 one. after mosaicking image displaying in a pixels rather continuous lines.
is there any way i can improve my mosaicking image …?

Could it be that you have missed to set the pixel size correctly.

2 Likes

might be sir. i will try now

its working sir. i given pixel value is 0.00281562730650646 because sentinel 3 has 300m resolution.

as u said i applied c2rcc for level 1 sentinel 3 data. now how can i compare units sir. could u plz explain me

The units are not set anymore to the band after mosaicking but they are still “mg m^-3” for chl.

Now you can load your data into the scene. as CSV file for example.
That’s explained in the help:

Alternatively, you can export certain pixels (the location where you have in-situ data for) and compare them with your data e.g., in Excel. You can use the Pins for doing this.
You can also have a look at this video. At 6:19 the validation starts.

You should also consider the flags which are provided by C2RCC. This is explained earlier in the video.

okay sir. I will try now
thanks.

sir, how to plot spectral reflectance graph in SNP

You find the Spectrum View in the menu.
image

Then you just need to hover of the scene.
To get the spectrum of specific pixels you can set pins.
The bands you want to see the spectrum must have assigned a spectral wavelength.

ok sir i will try .
thank you