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ion of
;nsing
)rs
its
red
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Remote
er
coastal
techniques
icean
i, 194-205.
is of oil
:. of
I ications
l-SP 188.
location of
;e features
?nsing
Geotechnical
sing, 26pp.
techniques
aging, SIRA,
Design
ial video
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of video
49th Annual
.M. 1985. A
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of plant
, 17,
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■ience
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Remote
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age analysis
Montreal,
a lysis of
the 50th
. Multiband
ts. 9th
ishments:
ared surveys,
ons Dir. 142pp
ibsurface water
lins in London
later, 32pp.
Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986
Study on the spectral radiometric characteristics and the
spectrum yield model of spring wheat in the field of BeiAn city,
HeilonJiang province, China (primary report)
Ma-Yanyou, You-Bochung, Guo-Ruikuan, Lin-Weigang & Mo-Hong
Harbin Remote Sensing Sub-centre of Heilongjiang Academy of Agricultural Sciences, China
ABSTRACT: Through the measurements and analysis of the growing condition and the yield of grain in 24 sample-
sites located in the field of BeiAn city with the spectral radiometers (WFD9), we have got the result that
Spring Wheat possesses most distinguishing features of reflective spectrum like those of other green plants,
but it has its own special feature. The curves of spring wheat reflection usually change with its different
growing stage and has certain rule of change. The reflective data of the radio between the band 5 and band 7
(MSS) seems to be closely related with the yield by using the method of regression. The results reinforce the
potential to us that we can forecast the yield of spring wheat before the harvest with measurements of radio
meter .
1. METHODS AND MATERIALS
The field experiment was located on the Black earth
in BeiAn city (47 40’-48 40’N, 126-127 50’ E) Heilon
Jiang Province. According to the historical yield of
BeiAn city, the field was divided into two levels of
yield: the high yield and the mid yield.
A Model "WFD9" radiometer with 16 field of view was
used to measure radiances corresponding to the Land-
sat MSS band 4, 5, 6, and 7, representing 0.5-0.6,
0.6-0.7, 0.7-0.8 and 0.8-1.1 um wavelenth, respec
tively. The reflectances were measured with two
radiometers (WFD9) on clear days throughout the
growing season of spring wheat. Readings were obtained
on 15 days during the growing season.
Our original intent was to use the reflectances
of spring wheat to establish the spectrumyieId
model and attempted to estimate the yield of spring
wheat with the measurement of spectral radiometer.
2. RESULTS AND DISCUSSION
In table 1, there is no difference in the reflectance
tendency of different crops, but in the band 6 or 7,
the differnces of reflectances are notable, it approa
ched from 13.2% to 41%. see fig.l.
In table 2, the difference of reflectance of the
variant growing stage of spring wheat also possesses
the same rule. The value of difference in the band 7
approached 7.86% to 19.31%
On figure 2 and 3, we have found the reflectance can
be used to moniter the growing strenth of spring
wheat. The reflectance of plants growing well is
higher than that of plants growing badly. The
difference in band 7 is very significant. The absorp
tion of sunshine is lesser and its reflection is
greater because the chlorophyll content of plants is
lesser at seedling and nodal stage. The absorption
and reflection of sunshine are stronger and weaker,
respectively, because the chlorophyll content of
plants is higher from hesding stage to milky matu
rity stage.
The reflective data of the ratio between the band
5 and band 7 seem to be closely related with the
yield by using the method of regression. We have
obtained the primary spectrumyield modal of spring
wheat as follows:
Y= -567.27 + 974 X (high yield spectrumyield model)
R = 0.87
Y= -907.3 + 2485 X (mid yield spectrumyield model)
R = 0.93
(note: X = log IR/R)
Figure 2. The spectral curves of spring wheat
growing well and badly in heading stage.
