The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Voi. XXXVII. Part B7. Beijing 2008 
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3. EXPEEERIMENTAL RESULTS AND DISCUSSION 
3.1 The canopy and leaf hyperspectral feature for spr- 
wheat in different stage 
In different growth stage, the hyperspectral reflectance of the 
canopy level and the leaf level are different, the hyperspectral 
reflectance of the canopy level and the leaf level are different, 
and that of the canopy is highest at jointing stage and lowest at 
ripening stage in the visible (VIS) region and in the shortwave 
infrared (SWIR) and the spectral variation trend is similar, 
meanwhile, that is highest at flowering-filling stage in the 
near infrared region. The green peak disappeared at ripening 
stage. On the contrary, the leaf hyperspectral reflectance is 
highest at jointing stage than other stage in the near infrared 
region, and the reflectance in green region is falling at ripening 
stage. 
In summary, the spectral difference is significant to monitoring 
the growth status in different stage. 
Figure. 1 The canopy and leaf hyperspectral for spr-wheat in 
growth stage 
3.2 The charactering of the canopy and leaf for spr-wheat 
in different density 
Fig.lA~Fig.lD show the reflectance of canopy and leaf at the 
booming and ripening stages in seven density scales (dl~d7 in 
dicate from sparse to bushy). It shows that the curves were 
similar but the reflectance values are different. The spectral dif 
ferences are clear for the canopy and leaves of spr-wheat under 
different density levels, and the canopy spectral reflectance are 
gradually getting smaller in the visible (VIS) region and bigger 
in the near infrared (NIR) region along with density level in 
creasing at booting stage, but this change is not evidence at rip 
ening stage. The difference of the spectral reflectance of the 
leaf from the top on the main stem is little in VIS region and 
great in NIR region at booting stage and this difference in VIS 
and NIR is coherence along with the different density. At rip 
ening stage, the spectral reflectance of the leaf is bigger in 
middle density level. And the leaf reflectance of D7 was the 
least because of the competitive growth, the LAI of the D7 was 
the least and the leaf reflectan was lower. Moreover, the other 
breeds have the same variety trends. 
dl d2 d3 d4 d5 d6 d7 
0.4 
waveband (nm) 
850 
1350 1850 
waveband (nm) 
2350 
leaf 
Figure.2 The charactering of the canopy hyperspectral for spr- 
wheat in different density at booting stage 
3.3 The hyperspectral in different for the spr-wheat 
The hyperspectral reflectance of the canopy and the leaf for the 
four spr-wheat breeds in the same density were compared and 
it indicated that there are no obviously difference in these four 
kinds spr-wheat in canopy spectral reflectance, while the spec 
tral reflectance difference of leaf level is clearly in the near in 
frared (NIR) region at booting stage, and the biggest is the 
Longchun8139, Dingxi24 the second, Heshangtou the third and 
Gaoyuan602 spr-wheat the forth. The difference of reflectance 
maybe connected with the bearing feature for each cultivar. 
The longchun8139 is a kind of earliness species and the plant 
growth is blooming. And the grown stage of Dingxi24 is longer 
and the leaf is bigger and the color of the leaf is thicker, the 
leaf of Gaoyuan602 and Heshangtou is little. It indicates the 
possibility to identify the wheat type using the hyperspectral 
reflectance data by the experiment. 
0.6 
Heshantou 
Figure.3 The leaf hyperspectral of the different species spr- 
wheat