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.
Solved
Query Regarding Vegetation indices
Best answer by elyhienrich
Hi
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!
+9- Community Manager 🌎
- 71 posts replied to
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!
+9- Community Manager 🌎
- 71 posts replied to
Hi
Glad to hear it! Let us know if you have any other questions.😊
+1hi, I have same the same problem, could you please tell me how to solve it?
+17- Community Manager 🌎
- 654 posts replied to
- Answer
Hi
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!
+1Hi
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
Enter your E-mail address. We'll send you an e-mail with instructions to reset your password.
©
Planet Labs PBC. All rights reserved.
|
Privacy Policy
|
California Privacy Notice
|
California Do Not Sell
Your Privacy Choices
|
Cookie Notice
|
Terms of Use
