anhul 2004
iamic four-
nent as the
ronment in
ning in the
in activity,
ace vehicle
s data and
es through
t models
and life of
dimension
ifts, space
the two-
:arth
a multi-
lanet into
SORE) A
aphor for
iment that
tual orbit
id grab a
', even an
, and you
il in 3-D.
ject and
uction of
imilar to
Jut it has
h object,
model,
rth" and
ta more-
ire space
vork, we
"Digital
IS Data
nds of
roperty,
cts have
mension
1 to five
the SIS,
nly line,
>] is the
nt.
data or
express
1 of the
it, there
lement.
that has
as the
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B2. Istanbul 2004
atmospheric temperature, the
atmospheric pressure and so forth.
The time specialty manifests tne space object's variable with
time change. For SIS, All kinds of the space environment
elements change with time, including instant variable and long
period variable. And besides, the space environment elements’
models must input the time dimension to be calculated.
The spatial relation includes topological relation, order spatial
relation, metric spatial relation and so on. For SIS, the solar-
terrestrial space was been considered as a whole body. All
kinds of space environment elements have one other relation;
especially they have strong relation with sun. And the space
environment elements’ distributing is also order.
The common sort method to the spatial object in GIS is layer
and level. For instance, the physiognomy can be sorted to river,
road, building, pipeline, etc. And river can be classified
different level. For SIS, the space environment can be sorted by
altitude to atmosphere, ionosphere, geomagnetic field, radiation
belt, etc. And every level has many sub-style sorted by variable.
atmospheric density, the
42.3 Showing Dynamic Transformation Applying time-
space Data Model
Already there are many design methods about the time-space
data model. For instance, time as an additional property data,
time as n new dimension, object-oriented methods and so on. At
present, the main data models include Time-slice snapshots,
Base Map with overlay, Space-time composite, etc. According
the space environment elements” distributing and time specialty,
we can adopt one model or methods, also can advance the new
model based on them.
4.2.4 Visually Express the Three-dimension Space
Applying the old terrain three-dimension visualization
technology, we can arrange space position by some space
environment element’ property to form the data set similar with
DEM (Digital Elevation Model), and render the three-
dimension scene by OpenGL. At the same time, we add time as
its other dimension. Thus, these models in simulation mostly
represent the dynamic sconces and computer motion.
For getting the whole visualization effect, we can directly form
more dimension data sets based on the physical and mathematic
models. In these setss, the space dimension was been divided to
cube body with the same border, and the property of every
point is the space environment element’ every parameters, such
as the atmospheric density, the atmospheric temperature, the
electron. density and ion density. For achieving the more
dimension data sets' visualization, we should redescribe and
plot by the data structure for the data sets, and set up
corresponding geometry model, then form the three-dimension
visualization image for any space environment element
property, through serials of the three-dimension visual
processing including projection transform, window reduce, light
model, colour adjustment and showing. Because there are many
properties in every space environment element, we only adopt
layer showing, transparency, translucency folding and
alternation switch, etc. showing methods to get every space
environment elements' visualization effect.
There is a test image to show three-dimension visualization
about the space, figure 1.
4.2.5 Space Analysis and Assistant Decision-making
Figurel three-dimension visualization about the space
In GIS, spatial analysis is the space data analysis technology
based on the position and configuration property of the
geographic objects, in order to find and transmit the spatial
information. According to the application order, there are many
analysis methods, such as network analysis, overlay analysis,
buffer analysis and the most short path analysis. In SIS, we can
analyze the aerospace vehicle circuit by referring the spatial
analysis models in GIS. For example, through calculating the
space environment elements’ property at some time and
position, based on the correlative buffer analysis model, we can
get the setss that affect on the aerospace vehicle, and control it
not into the dangerous region. In conclusion, Combining the
practice mission and GIS application analysis, we can advance
the aerospace vehicle circulating safety.
5. CONCLUSION
In this paper, based on the research of GIS technology and the
solar-terrestrial space environment, we extend the research field
and object in GIS to the entire solar-terrestrial space and
advance the concept of SIS-The Sun-Earth Space Information
System. Later, It demonstrates that application of GIS to the
space environment is feasible, and gives the concrete methods
to resole the space environment problem by GIS. It not only
extends the application of GIS, but also brings new method and
way to study the space environment. But it only the simple
research that apply GIS to study the Sun-Earth Space
Information System, and there are many problems waiting for
us to resolve.
6. REFERENCE
References from Journals:
GONG Jian-hua, LIN Hui, 2001, Study on Distributed Virtual
Geo-Environments, Journal of Image and Graphics,
Vol.6(A),No.9, pp.879-885
Li Shuo, ZENG Zhi-yuan, 2002 A Preliminary Study on
Integrating GIS and Environmental Modeling, Journal of
Glaciology and Geocryology, 24(2), pp.134-141
ZHANG Rui-xin, WU Li-xin, 2002, 3D Geoscience Modeling
and Virtual Mine System, ACTA Geoduetica et
CARTOGRAPHICA SINICA, 31(1), pp.28-33
References from Books:
Environment System Research Institute, Inc. Map Objects: GIS
and Mapping Components, ESRI Press, 1996