Update README.md

README.md

@@ -90,11 +90,18 @@ prospect = pyrism.PROSPECT(N=1.5,
 
 To access the attributes there are to ways. Firstly, we can access the whole spectrum with `prospect.ks` (scattering coefficient), `prospect.ka` (absorption coefficient), `prospect.kt` (transmittance coefficient), `prospect.ke` (extinction coefficient) and `prospect.om` (the division of ks through ke). Moreover, you can select the coefficient values for the specific bands of ASTER (B1 - B9) or LANDSAT8 (B2 - B7). To access these bands type `prospect.L8.Bx` (x = 2, 3, ..., 7) for Landsat 8 or `prospect.ASTER.Bx` (x = 1, 2, ..., 9) for ASTER.
 
-To calculate the PROSAIL model we must call SAIL and specify the scattering and transmittance coefficients with these from PROSPECT like:
+To calculate the PROSAIL model we need some soil reflectance values. To obtain these we can use the LSM model:
 ```python
-prosail = pyrism.SAIL(iza=iza, vza=vza, raa=raa, ks=prospect.ks, kt=prospect.kt, lidf_type='campbell',
-                     lai=3, hotspot=0.25, soil_reflectance=3.14/4, soil_moisture=0.15)
+lsm = pyrism.LSM(reflectance=3.14 / 4, moisture=0.15)
 ```
+
+Now we must call SAIL and specify the scattering and transmittance coefficients with these from PROSPECT like:
+```python
+prosail = pyrism.SAIL(iza=iza, vza=vza, raa=raa, ks=prospect.ks, kt=prospect.kt, rho_surface=lsm.ref,
+                      lidf_type='campbell',
+                      lai=3, hotspot=0.25)
+```
+
 The accessibility of the attributes are the same as the PROSPECT model.
 
 # Documentation