The International Archives of the Photogrammetry. Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B4. Beijing 2008 
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raster operations like transformation using different linear and 
non-linear algorithms, mosaicing, colour-balancing and tools 
for the reprojection of raster data. TopoL gives 3D functionality 
including the capacity to work with 3D vector data and to create 
DTMs from them. This is important for planning and navigation 
over terrain models. 
Some important and useful parameters are computed then, e.g. 
the stereo-base, ground size of the image, above ground level 
and the expected accuracy in position and heights. The number 
of strips and photos are shown in a first approximation. If some 
values are changed by the user, AeroTopoL computes 
automatically the new set of lines and images. 
3. MISSION PLANNING 
This possibility to read and transform raster data as well as to 
combine data of various sources and geodetic datum is a very 
big advantage over traditional FMS. The superimposition of 
raster and vector data provides all the background information 
needed for efficient mission planning while topological data 
structures further enhance the sophistication and precision of 
the flight planning process. 
Full access to various tools for drawing and topological vector 
structure make the definition of the areas very precise and 
effective. Snap parameters can be set in range and separately to 
grid, point, line, vertex and end of lines. Drawing lines in 
parallel or perpendicular is possible as well as the automated 
building of buffers for points, lines and areas. The full design 
capabilities of a GIS-based FMS solve all challenges in defining 
the project areas, and reduce the manual intervention in the 
flight planning process, e.g buffering and segmentation useful 
in corridor mapping projects. 
A tool for planning flight campaigns with analogue or digital 
cameras has been created based on TopoL NT technology. As a 
specific function, different geocoded data can be combined into 
one map-window with the target-coordinate system for the later 
flight- campaign. Rasters like TIF, JPG, BMP, CIT, SID etc... 
and vector data like DGN, block, DXF, shapefile... can be used. 
To make the application easy to use for less experienced GIS 
users, a wizard guides the user through all settings and 
procedures. Single projects for areas, river projects with buffer 
and meta-projects for a combination of several areas and rivers 
can be developed. Besides choosing from the range of target 
coordinate systems, the project perimeter and area must be 
defined. This can be done either by importing vector data, 
perhaps supplied by the customer as a shapefile or TopoL 
Block, or by opening a DXF where topological lines and areas 
are built automatically. 
Drawing a project area over a geo-referenced raster in 
AeroTopoL gives access to the full functionality of the base 
GIS. The boundary is drawn first and that polygon is selected as 
the project area. The next step is to preset the flight-direction 
(track). The camera-type can be selected after then, either 
analogue or digital. The user defines key parameters of the 
project such as overlap, sidelap and image-scale. In each case 
the user can check the number of flight lines and the number of 
images, as the system automatically calculates them. The 
parameters of the camera can be selected either by the 
predefined ones or new cameras can be defined using the 
parameters of the 
calibration-protocol. 
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relevant 
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define the 
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Based on an average terrain height, AeroTopoL computes the 
runs with the 3D release-points for the camera. Runs and points 
are displayed on the map and can be further modified. 
Individual images can be enabled, disabled or deleted as well as 
lines and new images manually added. Single images can be 
placed between existing ones either in the middle or anywhere 
on the run, which may be useful in some terrain or in urban 
areas. The complete block then can be shifted in any direction. 
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Figure 2: Map-window with table to edit the planned mission. 
3.1 Footprints: 
Displaying the footprint of selected photographs assists the user 
to assess all planned photo centres. This function is suitable to 
check for areas with good overlaps. This can be used do 
monitor for places where ground control points would be 
appropriately placed. 
Figure 3: using 
footprints and 
topological 
intersection of them 
creates a vector layer 
with a detailed 
overlap-analysis 
3.2 Activate selected areas only 
If a project should cover a couple of small areas with one 
mission and one block, a second vector layer can be used as a 
filter. For example, a project might cover only the developed 
areas of several small villages that are in close proximity. It is 
desirable to minimise turns on the flight lines, and to have 
maximum efficiency in the overlap. Using GIS data of specific 
layers as a filter to define these limits, we can plan the mission 
as a block covering all area and eliminate the redundant images 
at the same time. It is also possible to do this for selected parts 
only by querying a connected database.