Faram ZO0& LAE acid SR 
Measurement Fonts. 
* 3 sb spo aba ; 
AONO S OREO Bey à 
où 
  
   
   
Farm 2026 LAE and MER 
Data Measurement Points 
  
  
  
  
  
ve 
* os 
VUE 
* 
  
  
  
  
  
  
  
  
Sis cr 
CAE TIGR ACIER f 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Fasım 158 1A! and MSR 
Bieasurenent Fobimes 
  
  
Farms 38 LAI ard MSP 
Measurement Pants 
Figure 2: Spectral and LAI data collection sites at various CIA locations 
2.3 Satellite measurements 
Landsat 5TM satellite images for the whole cropping 
period were downloaded and processed to extract NDVI 
data. Firstly the images were pre-processed and 
reflectance data (relative at sensor reflectance -Toar) was 
further processed and transformed into absolute 
ground/surface reflectance (Surf) using two atmospheric 
correction models: Mid Latitude Summer (MLS) and 
United States (US) standards in Grass 7.0 environment. 
Both the models can be used under Australian conditions 
where both models gave almost identical results. Using 
all forms of reflectance measurements, different NDVI 
maps were created for each crop. The first one was 
created using the reflectance which was not corrected for 
the atmospheric error (NDVIToar), the second by using 
the reflectance values which was corrected for 
atmospheric errors using MLS model (NDVIy;s), and 
the third one was created in the same way but using the 
US model (NDVIys).These maps were used to extract 
corresponding NDVI values at field sample points. 
  
1.00 
0.90 
0.80 
0.70 
S 0.60 
ê 
S 0.50 
e 0.40 
= 0.1653In(x) + 0.5475 
R?= 0.8309 
0.30 
0.20 
0.10 
  
0.00 
0 1 2 3 4 5 6 
LAI 
  
The LAIg, NDVIg, NDVIyoar And NDVIgurr Values were 
used appropriately to develop different regression models 
and analysed the reliability of data sets and presented in 
following figures (3 to 10). Due consideration was given 
to phenological growth of crops in selecting the trend 
lines between different data sets regardless of best fit 
trend line. The shape of fitted lines is in the harmony 
with the crop growth phenology and shows that the 
NDVI saturates when crops are close to harvesting stage 
giving a good correlation. 
3. RESULTS AND DISCUSSION 
Error! Reference source not found.Figure 3 shows the 
regression relationships between LAIg and NDVIToar for 
corn. The corresponding regression relationship between 
LAI; and NDVI; and LAIg and NDVIys is shown in 
Figure 4 and 5. It is clear that the atmospheric correction 
process has significantly improved the results of the 
     
relationship between LAI and NDVI for Landsat 5 TM. 
  
  
  
1.00 
0.90 
0.80 
0.70 
2 0.60 
2 
0.50 
0.40 
0.30 
0.20 
0.10 
0.00 
s 
NDVI 
  
  
  
Figure 3: Relationship of LAIg and NDVIroar for corn crop Figure 4: Relationship of LAIg and NDVImzs for corn crop 
  
  
  
NDVI Toar 
  
NDVIiia 
  
Figui