1

I have this paper. In equation 2 they are calculating surface emissivity. I want to ask what is 𝑷v plant proportion?

https://www.researchgate.net/file.PostFileLoader.html?id=5760fe20b0366df3a5237081&assetKey=AS%3A373137431646209%401465974304318

𝛆 = 𝜺𝝂*𝑷𝝂* 𝑹𝝂 +𝜺𝒔 [𝟏 −𝑷𝝂] 𝑹𝒔 +𝒅𝜺
 𝑷𝝂 is the vegetation proportion in a pixel

Was it calculated from NDVI?

2

Based on the article:

Land surface emissivity was calculated using the NDVI threshold method [38] suggested by Beck et al. [42]. The assumption is that bare has a NDVI < 0.2 [42]. The land surface is considered to be completely covered by vegetation if NDVI > 0.5 [42]. When the NDVI values are between 0.1 and 0.5 (0.1 ≤ NDVI ≤ 0.5), the land surface is considered to be covered by vegetation and bare soil mixing.

As such, P_v is 0 at NDVI < 0.2, 1 at >0.5 and scaled inbetween (on a related note, the values used in this article were chosen for their location. Your location may require different values).

Calculating such a 'fractional vegetation cover' map is done using a linear regression and a raster calculator.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.