How to retrieve The Red-Edge Inflection Point Index (REIP) using SNAP?


I am using SNAP to retrieve REIP using available tool. The sensor specific formula to derive the REIP using Sentinel-2 MSI is found in its help as below

700 + 40 * ((B4 + B7)/2 - B5) / (B6 - B5)

However, the tool dialogue indicates different processing parameters to fill in;

According to the syntax, Band 7 is to be inserted, however, the dialogue box requires NIR band source which is Band#8. How would I populate this dialogue box to derive the intended results.

I think this depends on the sensor you are using. I would therefore rather trust the formula as given in the help or in cited literature than the numbers in the module. But for this case it offers to select the bands themselves.

This might help to clarify potential mismatches regarding the band numbering of sensors.

As indicated, the index is sensor specific and I am using Sentinel-2 MSI. I am following the syntax provided in SNAP help but the problem is limited to REIP dialogue box. It asks to insert NIR band instead of Red Edge band number 7?

According to the source article [Guyot and Baret, (1988)], r780nm is the NIR. This is why the last band label is NIR.
If you are using the most recent SNAP version (5.0.4) and you load a Sentinel-2 product, you will see that the index parameters window will pre-populate the field “NIR source band” with B7 (783 is closer to 780 than 842). However, you are free to change it to B8 if you wish.

Thank you kraftek for your help. I hope this will work.

@kraftek you are right. Thank you very much for providing help in this regard.

I am glad that I could help.

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Maybe interesting here (comment from 2019):

@ kraftek