Opticalscape


In the past decade - particularly with the ability to mount digital optical devices on low cost Unmanned Aerial Vehicle (UAV) platforms - the generation of Digital Surface Models (DSM) based on stereo-optical images has become a major component for an extensive number of applications at local scale, such as mapping, virtual terrain reconstruction and visualisation, simulations, civil engineering, precision farming, precision forestry and others. This DSMs category complements the more conventional one based on spaceborne imagery, which, in the same period, has seen an important evolution in terms of resolution and acquisition technology (triplet).


Modules

OPTICALscape is a modular set of functions supporting the generation of DSMs based on spaceborne and UAV stereo-optical data. The two modules - developed in collaboration with 4DIXplorer, a spin-off company of the Swiss Federal Institute of Technology Zurich - are complemented by a multi-purpose tool including a wide range of functions, from image visualisation to cartographic and geodetic transforms.

Spaceborne stereo
It supports the processing of image pair and triplet in terms of image orientation to automatic DSM and ortho-image generation. Key feature is the DSM generation, which is based on the most advanced algorithms thoroughly considering the new sensors characteristics. The figure illustrates a DSM based on Ikonos image pair.

Main functionalities are:
    - Orientation of single, stereo and triplet imagery;
    - Ground Control Point and Tie Point measurement;
    - Derivation of quasi-epipolar images;
    - Automated DSM generation;
    - Generation of ortho-rectified images.

An additional functionality is dedicated to the fusion of elevations by considering the different sensors characteristics and corresponding processing techniques. The figure shows, as example, DEMs based on ALOS PALSAR-1 (left), SPOT-5 (right) and their sensors driven fusion (centre).

OPTICALscape supports following spaceborne optical sensors
    - Cartosat
    - GeoEye
    - Ikonos
    - Pleiades
    - PRISM
    - QuickBird
    - SPOT
    - WorldView


UAV stereo
It supports the processing of image pair series in terms of image orientation to automatic DSM and ortho-image generation. Key feature is the DSM generation, which is based on the most advanced algorithms, and the automated DSM and ortho-image mosaicing. In order to facilitate the image orientation, images must include a coarse platform position, while attitude data are not mandatory. The figure illustrates a DSM mosaic and the corresponding ortho-image mosaic.

Main functionalities are:
    - Orientation of multiple stereo pair;
    - Ground Control Point and Tie Point measurement;
    - Derivation of quasi-epipolar images;
    - Automated DSM generation and mosaicing;
    - Generation of ortho-rectified mosaics.


Opticalscape technical description