Hi I would like to ask, can the calculation of NDVI process after doing the supervised classification? And how you process the image that you use for the NDVI process? I’m a beginner and I’m not quite understand
Hello, thanks for the videos, they are really helpful! Using Sentinel-2 Data, I would like to calculate the Urban Index with the formula (B12-B8)/(B12+B8) but it doesn't work. The error message is "Please check the band maths expression you have entered. It is not valid." which I don't have an explanation for.
I noticed there are slight differences in the values between the two NDVI methods. From the band maths the min value is -0.59742975 and max value is 0.515567128. From the vegetation radiometric indicies the min value is -0.60189227 and the max value is 0.522966611. Do you know a reason for the differences?
The radiation is NOT absorbed by the water but reflected. This is called specular reflection. Thus, nothing is reflected back to the sensor and the water appears black as no values can be captured for that area.
For applying atmospheric-, terrain and cirrus correction of Top-Of- Atmosphere Level 1C input data Watch this video for applying Sentinel-2 correction using Sen2cor plugin th-cam.com/video/ZDjY1eJ-9kg/w-d-xo.html
I loved the video, simple and comprehensive for a first time SNAP user...I found this very useful!!!
It was VERY VERY VERY HELPFUL ! thank you so much
Great tutorial. I am wondering how can I use some NDVI reference data for validation of the SENTINEL-2 derived NDVI? Please let me know
Don't you need to perform atmospheric correction for L1C data?
Ideally yes - we cover that later but you can use sen2cor
Thanks for your teachings, have a video or tutorial explaining the NDWI classification. Greetings.
Thanks for this great video!
Great tutorial, thank you
Wow thanks for this video
Thank you! It helps a lot!
Is there a way to obtain NDVI from Sentinel-3 imagery?
why you don't do first the refletance?
Hi I would like to ask, can the calculation of NDVI process after doing the supervised classification? And how you process the image that you use for the NDVI process? I’m a beginner and I’m not quite understand
Are the NDVI results from SNAP of the same quality as arcgis? Thanks
Hello,
thanks for the videos, they are really helpful!
Using Sentinel-2 Data, I would like to calculate the Urban Index with the formula (B12-B8)/(B12+B8) but it doesn't work. The error message is "Please check the band maths expression you have entered. It is not valid." which I don't have an explanation for.
I noticed there are slight differences in the values between the two NDVI methods. From the band maths the min value is -0.59742975 and max value is 0.515567128. From the vegetation radiometric indicies the min value is -0.60189227 and the max value is 0.522966611. Do you know a reason for the differences?
Very useful, thanks!
great content sir, helped a lot
Is that possible to calculate STR in SNAP
I have a question, what if I want just to calculate the Ndvi in water how will I go about it? I'm still a beginner using SNAP
How come that your Sentinel 2 imagery is so much more hi-res than mine? If I download it from USGS or Copernicus it is much more 'pixely'.
Same
I am late...but this is clear and interesting video!
The radiation is NOT absorbed by the water but reflected. This is called specular reflection. Thus, nothing is reflected back to the sensor and the water appears black as no values can be captured for that area.
No this is not specular reflection - its absorption by water in the NIR and SWIR which makes water appear black in these wavelengths.
Great 👍🏻
Thanks
My snap does not open zip-file. What is problem?
This sometimes happens when the .zip is corrupted or hasn't downloaded fully. Check the file size - it should be 500-700 mb for a Sentinel-2 scene.
I solved the problem. It was outdated soft. But thanks.
I can not open zip -file how i solve it @@РусланШевчук-ь8я
For applying atmospheric-, terrain and cirrus correction of Top-Of- Atmosphere Level 1C input data
Watch this video for applying Sentinel-2 correction using Sen2cor plugin
th-cam.com/video/ZDjY1eJ-9kg/w-d-xo.html