The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B7. Beijing 2008
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2. LANDFORM MAP RENEWAL USING REMOTE
SENSING IMAGE
Because most of landform map of our country were plotted
before the 1980s. Road, habitation and other elements have very
large changes. Additionally because of adjustment of
administrative division of villages and towns, administrative
division of County and under County has also very large
changes, which are not reflected in the original map. As a
foundation map of field investigation exploration and coal
geology mapping working, the existing landform map already
had no means of meeting real work demand, thus renewal is
urgent.
Data of satellite remote sensing image is strong in real-time
feature and wide in covering surface, already becoming an
important approach of obtaining and renewing information
needed by heterogeneous, difference scale databases of state
basic scale topographic map and state fundamental geography
information system. Thus it is required to adopt remote sensing
image of different resolution to carry out renewing processing
for existing landform maps and collect a great deal of relevant
data and documents for correction.
Scanning and rectification are performed for existing map data
and numeralization are performed according to job specification.
Then according to scale, high resolution SPOT, IKONOS,
Quickbird and other images are adopted to carry out
rectification and mix processing of geographical coordinates.
After mosaic, cut is performed to generate images map
coordinates. After understanding local basic status in remote
sensing image and map, sampling of field investigation and
keystone region are ascertained to carry out survey and plotting
in the field to obtain identification characteristic of image and
collect data from local related departments at the same time.
According to the collected document and field investigation
experience, remote sensing image is utilized to carry out
renewal for digital map and carry out inspection for renewing
results. Finally according to principle of map design, map layer
design, symbolization map decoration and other workings are
performed to obtain the aesthetic and precise map data.
3. HIGH PRECISION REMOTE SENSING GEOLOGY
MAPPING
Because current 1: 250000 area mapping working and original 1:
200000 geologic map of our country had no means of meeting
the working precision of survey and exploration of regional coal
resource, as a basis of coal resources exploration, it is also
urgent to unfold 1: 50000 or bigger scale geologic mapping
working of keystone region.
As a kind of basic technique means, remote sensing technique
has been extensively used by geologic survey work. Along with
unceasing elevation of aerospace remote sensing technology in
spectra and spatial resolution aspects, it furnishes new
development chances for geology application of remote sensing
again. For example, airborne hyper-spectra, multi-spectral
technique can obtain the remote sensing image and data from
space at the same time, thereby furnish narrow band, hyper
spectra, high resolution reflecting data and gray scale value for
surface geology spectrum quantitative analysis and also furnish
strong document support for the geology personnel to use the
computer technical classification directly to generate the
required enhancing information image of rock and mineral.
By means of remote sensing technique, taking the regional
geological mapping as objective, it applies the image unit
method, image rock unit method and unit profile method
rationale to carry out explanation for regional strata, rock mass,
structure and other factors.
3.1 Sedimentary Strata aspect
1. Quaternary sediment explanation can use the remote sensing
image to ascertain manifold genetic types of quaternary system,
whose certainty of geological boundary and modal plotting
surpass ground reconnaissance geology survey.
2. It can identity the boundary of mapping unit of formal
lithostratigraphic unit, whose accuracy ratio can reach 80—100
% except individual segments. It can trace and ascertain
informal stratum unit extension and pinch out, more portable
and accurate than ground trover.
3. Combined with high resolution satellite image or aero
photographic image, it can carry out identification for contact
relation among strata, such as unconformity, parallel
unconformity, more effective especially for tectonic contact
relation.
4. It can carry out a trover for lithofacies variance of identical
stratum, especially lava variance situation in lava strata, whose
effect surpasses ground investigation.
5. According to predominance of remote sensing image which
is wide in visual field and strong in transverse contrast, it can
correct locations where predecessor has processing errors and
can set up stratigraphic framework of surveyed area remote
sensing to direct fieldwork demonstration working.
6. It is self-explanatory that remote sensing image has
predominance for unfrequented regional strata mapping.
3.2 Magmatic rock area
1. Remote sensing image can almost reach 100% for identifying
rock mass borderline and the plotted rock mass boundary
surpass ground observation in accuracy rating.
2. The recognition rate is greater than 60% for complex interior
unit boundary.
3. It can only identify main class currently for lithology
discrimination, with concrete detail needing a fieldwork.
4. In the section where interpretation effect of middling
resolution image explanation is better, combined with high
resolution satellite image or aero photographic image, it can
differentiate vein rock, the order interpenetration relation,
distribution regularity, coping residual body, wall rock xenolith
and wall-rock alteration phenomena in rock mass. It can also
identify partial schistosity, contact relation and other structure
phenomena and furnish macro information for perching
mechanism of rock mass.
5. By utilizing remote sensing predominance, it can carry out
re-merger and disinterring for magmatic rock unit and sequence
for which predecessor partition and merger is comparatively
turbid.