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

60
lief and curvature. Orthophotoimages preser
ve all details of initial images and present
data on the Earth's surface in corrected co
ordinates at the same time. Being the end
product of a chain of photographic transfo
rmations orthophotoimages have a somewhat
reduced resolution. Photogranmetry has ma
de it possible to expand research on the
use of orthophotoimages to obtain photomaps
in many fields of geographical application
orthophotoimages acquire paramount importan
ce, particularly so in space-based thematic
mapping of mountainous areas.
Photogrammetry palys a vital part in cre
ation and practical use of space photomaps
which are complex cartographic-photogram-
metric models (HobskobCKMM, 1983). The exact
nature of photogrammetrie processing is de
termined by at least the three main groups
of factors depending on conditions of spa
ce photography. The orbital movement of spa
ceship itself refers to the first group.
The second group is accounted for by tech
nical characteristics of the space photo
equipment: its resolution, dreal scope, mul-
tispectrality etc. The third group of fac
tors includes the geometric conditions of
space photography (the height and the tra
jectory of the orbit, the direction of the
camera's optical axis at the moment of ex
position) and the properties of the photo
graphed object itself such as surface cur
vature, relief etc. That is important not
only for the application of space images in
carthography but for setting up an environ
mental monitoring as well. The carto-photo-
grammetric processing of space images of
the Earth is primarily defined by the orbi
tal parameters which influence the scale,
ovelapping and geometric properties of ima
ges decisively.
It should be noted that the space survey
routes when mapped show as complicated cur
ved paths. Being a function of orbital pa
rameters they can't be changed once the or
bits is given. That's why the route planning
for mapping given geographical regions and
route repetitiveness are of special impor
tance in remote sensing. Thus there is no
chance of plotting a space survey route in
a latitudinal (east-west) direction as it
is usually done on aerophotographic surveys.
The value of the forward overlap of photo
graphs is the most important parameter for
the space image - based cartography. It de
termines the choice of appropriate techni
ques of cartophotogrammetric interpretati
on of data obtained, including the building
up of cartometric data bases - digital mo
dels of natural objects. The value of the
forward overlap p/° can be easily derived
from the following analytic dependence for
the time interval t between the two succes
sive expositions:
t= 2R /
W \ 100%
arc sin
H + R
sine
where W is the speed of movement of the
subsatellite point, R - mean radius of the
Earth, p - half-angle of the camera's visi
on field. It should be noted that the for
mula doesn't take into account the effect
of the Earth's rotation (НоваковСКИЙ, 1981).
Also of importance area the angle of sloping
of orbital stereophotoimage3. They to a gre
at extent determine the choice of effective
techniques of carto-photogrammetric proces
sing and data interpretation. The latter ac
quires particular importance when orthopho
toimages used for making space photomaps are
obtained b^ means of the analoguephotogram
metric techniques.
Let us illustrate our analysis of the se
cond and third groups of factors influen
cing the effectiveness of the remote sen
sing data use in geographic cartography on
the example of a specific orbital photo-ex
periment. We shall study the photographs
taken by the multispectral MKF-6 earners du
ring the "3oyuz-22" flight (commander V.F.
Bykovsky, flight engineer V.V.Aksyonov, 15-
23 September,1976). As it was stated in se
veral studies (Linsenbarth,1978, НоБЭКОВСКИЙ,
1981, Proos,1982, Guske, Kluge,1982) the
carto-photogrammetric peculiarities of the
images taken present wide possibilities for
their effective use in cartography (especi
ally in compilation of orthophotoimages and
photomaps) for geographical purposes.
Let us illustrate certain practical aspec
ts of such compilation in the instance of
analysis and processing of orbital stereo
scopic pair of photographs taken by the "3o-
yuz-22". These images cover the south-eas
tern part of the Fergana valley and north
ern ridges of the Pamiro-Alay mountain sys-
tem-Turkestan and Alay (near-Fergana physi
co -geographic regions), the Alay valley and
the Trans-Alay ridge (the Pamir region). Ex
perimental works have been carried out on
the two different analogue photogrammetric
complexes of used to compile stereomaps: or
thophotoprojector OFPD and stereograph SC-1
(USSR) and Topocart - Orthophot-B (GDR).
The techniques of producing space ortho
photoimages and photomaps with this modern
photogrammetrie equipment, the theoretical
foundations of these techniques, merits and
shortcomings of the equipment, itself, ana
lysis of the accuracy of the results etc.
are the subjects of special research (see,
for example, Новаковский,1983, Балашов,
Мантров, Решетов, Сигалов ,1984). within
the framework of this paper we shall consi
der the peculiarities of photogrammetric
compilation of relief pictures including
their presentation on a photomap. That would
enable us to take up the problem of its di
rect use fer compiling various morphometric
maps for their further analysis. The drawing
of relief by isolines (1:500 000 scale) on
the Topocart device was conducted after the
same scale orthophotoimage was obtained with
orthophotoprojector Orthophot-B (Новаковский,
1983). Diapositives enlarged approximately
1.7 times from the 1:2 120 000 initial spa
ce double-negatives were used. Drawing was
made on plastic by the traditional stereo
photo gramme trie technique.
It's known that continuous isolines on
1:500 000 topographic maps of mountainous
areas are drawn with 100 m intervals, or
some special symbols (cliffs etc.) are used.
It should be noted that if the isolines i3
0.1 mm gap between or les3 steep slopes
they nay be merged at stretches no longer
than 1 cm (according to the map's scale).
Two or three intermediate isolines may be
drawed between broadened isolines (worth
500 m) with the rest c.f them interrupted.
The relief map compilation has demonstrated
that the above described technique of dra
wing isolines with a 100 m interval are in
expedient for the Pamiro-Alay area, becau
se the isolines practically fully cover the
photoim
formati
king in
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