Skip to main content

Hi!
I have been trying to compute some vegetation indices suing 8band PS data. The generated NDVI his in its range of -1 to +1 but I am not able to get the suitable range for other indices like EVI, EVI2 etc. These indices are coming up in ranges of -4000 to +5000 with most of the data concentrated between 0 and 2. 
Could you please tell why is it happening?
I am using Qgis for the computation of these indices.

Hi

After our investigation, we think that more information will be needed to answer your question. Therefore, we’ve created a support ticket on your behalf and copied the email that you used in your community account. 

Let us know if you have any further questions. 

Have a nice day!


Thank you for your reply!
The query has been answered by the support team. 

Have a great day!


Hi @Sonakshi Mehrotra,

Glad to hear it! Let us know if you have any other questions.😊


hi, I have same the same problem, could you please tell me how to solve it?


Hi ​@PKK and any other users who have similar questions:

If you are experiencing anomalous pixel values in bright features such as heavy clouds or snow/ice when calculating the EVI index, you can work around this issue by excluding clouds and snow/ice areas from the calculation or by setting extreme pixel values to (-1) for a more visually appealing representation of the index. For example, you can set extreme values to (-1) in QGIS using the raster calculator. Here's how:

In the raster calculator, insert the formula below, where EVI_index@1 represents the raster file containing the EVI index:
if("EVI_index@1" < -1 OR "EVI_index@1" > 1, -1, "EVI_index@1")

I hope you find this helpful. If you have any questions or concerns, please don’t hesitate to let us know.

Thank you!


Hi ​@PKK and any other users who have similar questions:

If you are experiencing anomalous pixel values in bright features such as heavy clouds or snow/ice when calculating the EVI index, you can work around this issue by excluding clouds and snow/ice areas from the calculation or by setting extreme pixel values to (-1) for a more visually appealing representation of the index. For example, you can set extreme values to (-1) in QGIS using the raster calculator. Here's how:

In the raster calculator, insert the formula below, where EVI_index@1 represents the raster file containing the EVI index:
if("EVI_index@1" < -1 OR "EVI_index@1" > 1, -1, "EVI_index@1")

I hope you find this helpful. If you have any questions or concerns, please don’t hesitate to let us know.

Thank you!

Thank you very much


Reply