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Title
Remote sensing for resources development and environmental management
Author
Damen, M. C. J.

Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986
419
The application of remote sensing technology to natural
resource investigation in semi-arid and arid regions
Ding Zhi
Institute of Xinjiang Biology, Pedology, and Desert, Academia Sinica, China
ABSTRACT: This paper is to clarify the method, principle, foundation, and results newly ob
tained in terms of aerial and satellite remote sensing techniligy, which was used for the
inve stigation of natural resources, such as forest,pasture, vegetation, soil and reeds in
the mountains and the marshlands regions. Finally, mapped with a scale of 1:50‘,*000. TVio ac _
couracy of these maps were tested to be 92.3%.
1 Introduction
Xinjiang is located in an arid and semi-arid
area. Thus, it is easy to collect remote sen
sing materials of better quality. Applying
remote sensing technology in this region to
investigate the natural resources fully de
monstrates its superiority. In the past few
years, we have utilized aerial and satellite
sensing to investigate the mountainous re
gions forests, grasslands, vegetation and
soil, and the marshland reeds resources.
2 methods and principles
First we use satellite photos of different
times and different seasons and aerial mul-
tispectral photos and conduct different band
composition coherent covering, stacking, and
ratio,etc. optical processing. And then,
combine the processed satellite photos, the
multispectral photos with the full colored,
black and white aerial photos to set up the
interpretation symbols and the indexing ca
talogue. Finally, we explain the type and
distribution of various natural resources
visually, and draw specialized diagrams.
All remote sensing images are pictures of
ground objects reduced to certain proportion.
The characteristics of the pictures reflec
ted on the remote sensing images are formed
mainly by the difference in information of
the tone and form characteristics.
The information of the characteristic of
tone is the characteristic of quality and
the energy of the electromagnetic spectrum
of the ground objects reflecting on the re
mote sensing images. Generally, the diffe
rence in the energy of the electromagnetic
waves recorded on the same remote images is
mainly determied by the reflection rate of
the spectrum of the ground objects. The theo
retical formula:is .
W =C K (x) • £ (x A, N H" 1 7' , K: the constant of changes with the wave
length.
£: the penetrating rate of the ground objec
ts reflecting and radiating in the atmosphere
N: the radiating illuminance of the direct
sunlight and the skylight.
P : the spectro-reflecting rate of the ground
obj ects.
However, on the same remote sensing image,
K, Z, N can be used as a constant. Thus, the
above-mentioned theoretical formula can be
simplified as follows:
W= K
A.: the wavelength
Or. the angle of elevation between the ground
objects and the sensor
ft: the aspect angle
cj>: the angle of elevation of the sensor
t : the azimuth
Also: D= K log ^ i is the positive)
D= K log-^— (j_ s th e negative)
D: the tone or density or the remote sensing
images
As in the same remote sensing image the
difference in image tone of the adjacent two
objects A and B are mainly determined by the
difference of the energy of the electromag
netic wave, that is by the difference in
reflecting rate between them:
iD - K w ^ los-£-
w a , wh are the energy of the electromagnetic
waves of A and B objects
Pa, y Pt are the reflecting rates of A and B
obj ects
K w 2 a constant, which influences the other
factors of the energy of the electromagne
tic waves
ip: a constant, which influences the other
factors of the reflecting rate
Therefore, according to the known density
of the images and the reflecting rate of the
spectrum on various ground objects, we can
classify various ground objects from the
remote sensing images.
The information of the form characteris
tics is in essence the spectrum of the ground
o bjects reflecting the rules of the time
and space of the ground objects, that is due
to the difference in the composition of ob
jects and undulation of the Earth's surface,
the characteristics of the images are for
med by the difference of electromagnetic
energy reflecting the same band. The existan-
ce and attributes of many objects can be de
termined according to the form of their ima
ges.
As mentioned above, the information of the
form and tone characteristics and the chara
cteristics of the images as reflected by
their combination on the remote sensing ima
ges, which are the main foundations for es
tablishing the explanatory sybols and in
terpretation.