59
Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986
Space photomaps - Their compilation and peculiarities
of geographical application
B.A.Novakovski
Moscow State University, USSR
ABSTRACT: Maps and modern space photographs serve as basic models and information sources
used in the geographical research. The key to their effective use in geography is there
fore in optimal combination of specific features of maps and space photographs. Such com
bination is possible through creation of space photomaps and their appropriate use. From
the technical point of view photomaps can be complied from space photographs converted
into orthophotoimages on the basis of analogue or photogrammetric orthophotoequipment. Pra
ctical aspects of obtaining space orthophotoimages and photomaps are illustrated by analy
sis and analogue processing of the stereoscopic couple of space photographs taken over the
Pamiro-Alay area by the "Souyz-22" multispectral MKF-6 camera. One of the specific featu
res of space photomap application is the possibility of improving the derived morphometric,
correlation and other maps. This is shown through the application of the hypsometric pic
ture (obtained by means of photogrammetry) aimed at compiling maps of morphoisolines, ho
rizontal and vertical relief dissection, erosion network and lineaments. Combination of
cartometry, morphometry, quantitative interpretation and mathematical-cartographical mo
delling is an important trend in the application of remote sensing and cartographic metho
ds of research based on photogrammetric approaches.
i the
Lied
likeli-
ed
and
lfor-
Of special importance for thematic interpre
tation of the remote sensing data is their
presentation in the form most suitable for
solving various scientific and practical
problems of geography. Cartography is beli*.
eved to the principal method that fully ma
kes use of the advantages and takes into
account the peculiarities of orbital images
of the Earth. Thematic maps based on the
interpretation of space images or photomo-
zaics are highly reliable. A new possibili
ty imerging out of space-based meso- and
microscale thematic cartography is the de
velopment of the research function of the
cartographic method.
From the comparison of space images and
maps it is evident that the former present
an integral uninterpreted picture of a cer
tain fragment of the Earth's surface in all
its geographical complexity. Out of that
complex picture maps reflect only an inter
preted and ordered in a certain way discre
te integral image depending on their themes.
It is thus quite natural that space photo
graphs are at a higher level than maps^in
the hierarchy of geographical models (Bep—
JIHHT t 1978) . Space images and maps have
some common and comparable features, such
as selectivity, scale and metricity, visu-
ality, singularity, geometric similarity
to actual objects on the Earth surface, as
well as territorial-geographic corresponde
nce. On the other hand there exist some es
sential differences between them especial
ly manifest in comparative estimates of
their abstractness, syntheticity and logi-
city (Neumann, 1981).
Modern maps, and space images are joint
ly used in the geographical research. They
can be processed by kindred methods of car
tometry, mass-scale extraction of morpho
metric and statistical information, crea
tion of digital and mathematic models. It
should De noted that it's not only simila
rity of maps and photographs as models of
reality that favours their joint applica
tion, but their differences (providing mu
tual complementarity) as well.
Modern thematic map is, thus, an impor
tant geographic model possesing many meri
ts as well as certain shortcomings. The
characteristics of space images make it
possible to limit or even eliminate certa
in negative features of maps. We believe
the decision to be in a search of optimal
combination of appropriate qualities of
maps and space images. Such a combination
is provided by the development and proper
use of space photomaps.
From the technical point of view space
photomaps are half-tone photographic pic
tures of the Earth's surface (black-and-
white or coloured) with background
and shading conventional signs
used in compiling coi’responding types of
maps .
The identification of necessary objects
on space images, their interpretation and
mapping are difficult tasks of cartographic-
photo gramme trie interpretation. The proces
sing of such pictures is apt to take more
effort than traditional techniques based
on small-scale aerial images do. That is
why it's expedient to transform space pho
tographs (especially those of high resolu
tion) into orthophotomaps. Such a treatment
leaves intact all details of plained con
tents while largely reducing the labour
consuming drawing procedures.
The modern optico-mechanical analogue or
electronic-digital orthophotoequipment al
lows the use of space images as maps proper
while traditionally they are no more than
a mapping base. The most valuable feature
of an orthophotoimage is it's uniform sca
le, facilitating exact cartometric measu
rements without any initial image correcti
ons for slope effects, area's surface re-
