Regions are objects "logically encapsulating data ..., local
co-ordinate systems, ... interpolation algorithms, private
surface representation (e.g. hexagonal tiling, or analytical
forms), functions to service inquiries concerning this
surface (elevation, components of f and f" at a given
location, the isoline at a given elevation, ray tracing, etc.),
and in some cases even hardware. They should employ
parallelity in their co-operation ... [Mo92].
Realized is: the organization for regions, and creating
separate SCOP DTM structures per region ("RDH").
4.2 (3D and Special) Enclaves
These are small regions with structures not necessarily
belonging to the terrain surface as represented on
topographic maps. Such structures are buildings, bridges,
but details such as roads, sport fields etc. can also be
classified as such. Small enclaves can just be neglected in
certain cases (e.g. in creating maps in scales too small for
representing them). If not small enough, the often just
abstract topographic surface must also be specified for
enclaves. Entire city models may be considered to be
special and atypical enclaves.
There are no enclaves realized at this point.
5. PROCESSING
5.1 Interactive Mode
The aim of this description is to give the reader an idea of
controlling SCOP under XX. This is a pre-alpha version, so
any detail can change; the general idea remains proper,
however.
Fig. 1 shows a screen with the main window SCOP DTM,
and two subWindows: ISO parameters, and Slope. On the
left side of the main window, a series of stateSwitches is
there to control Data, Views, and SURFACES. Clicking at
the stateSwitch 'iso' with the right mouse button will open
the subWindow for setting up parameters. There, interval
and/or levels can be specified. A left click at the button
'Update' will result in taking over the values specified. It
does not result in displaying isolines on the screen.
To display contourlines (isolines), the state of the switch
has to be raised. This is done by left-clicking the
stateSwitch, and hitting the right arrow or carriage return
on the keyboard. The small bar on the stateSwitch will light
up and blink in yellow - the blinking indicating the process
running. The iso agent will be sent a message, it will
request the contour lines at the agent for algorithm tiling. It
then will initiate the interpolation for all regions within the
area of interest (the area represented on the screen), then
it will start SCOP.ISO to interpolate the contour lines.
When all this is done, the iso agent will send the (address
of the) interface object with the contours to GX. GX will
display the contours. Finally, the iso agent will send a
ready message to UX; the stateSwitch iso will sease
blinking, the yellow light remains to indicate the state
‘displayed’ for isolines.
On the right side of the SCOP DTM window there are
different buttons. 'What if should serve to create one or
more copies of the DTM so to experiment and to compare
results. Explore, when 'opened', will present different
means for "surface analysis and exploration”, including,
e.g., SCOP.SLOPE. Applying the latter will create a slope
model; when created, it will appear on the left side under
SURFACES (stateSwitch ’Slope’, when opened, the
vertical window on the right side appears, showing for this
model the same stateSwitches seen on the left side of the
main window).
The button ’Map’ under WINDOWS" will open a graphics
window for editing output graphics.
Placing the mouse pointer over any symbol will display a
short help string in the help bar along the lower edge of
the corresponding window. F1 will yield detailed help.
For expert users, there is also a commandLine available.
It controls all levels (main and subWindows) of processing.
With commands as suited for it, command procedures can
be written.
5.2 Compatibility
This coming version of SCOP integrates the modules of
the most recent SCOP version as server components.
They are capable of running in exactly the same
"traditional" ways users of SCOP are accustomed to.
6. CONCLUSION
The main improvements in this presented version of SCOP
are its openness toward future development and toward
integration. Only in the second line would we mention the
great improvement in processing control, and the
introduction of regions.
At least half of the tasks formulated in [M092] remain
open. There is much work underway. Closer to become
applicable are:
- line networking (break lines, region limits)
- true 3D surface interpolation and representation
- intelligent overlapping/mixing of related views
- raster tools (a related reference: [Ri92])
REFERENCES
[Co95] Cotter, S. Inside Taligent Technology. Addison-
Wesley, 1995. ISBN 0-201-40970-4.
[Ho96] Hochstóger, F. Software for Managing Country-
Wide Digital Elevation Data. International Archives of
Photogrammetry and Remote Sensing, Commission IV,
Vienna, 1996.
[Lo91] Loitsch, H., Molnar, L. A Relational Database
Management System with Topological Elements and
Topological Operators. Proceedings Spatial Data 2000,
Dept. of Photogrammetry and Surveying, University
College London.
[M092] Molnar, L. Principles For a New Edition of the
Digital Elevation Modeling System SCOP. In: International
Archives of Photogrammetry and Remote Sensing,
Commission IV, Washington, D.C., 1992.
[Ri92] Rieger, W., Automated River Line and Catchment
Area Extraction from DTM Data. Presented paper, ISPRS
Congress, Washington, D.C., 1992.
574
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
Wil
Th
60
the
es
Ag
lar
the
be
su
me
ne:
ma
the
we
the