From Landsat7
Orthorectification of Aerial Photo
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Landsat7 ETM+
The original source of satellite image used to build international data set can be describ as:
- red is mid-infrared light
- green is near-infrared light
- blue is visible green light
and looks like it.
After remixing colours channels to give "simili true color"
and resize to perfectly fits the digital elevation model, we obtain this
Srtm Digital Elevation Model(DEM)
After patching missing data and changing projection to UTM,
we can render a 3d frame like this one. Of course it is not a straitdown point of view.
Mixing image and DEM in 3d Scenery
With openGL graphic renderer it is possible to mixe image and frame in order to obtain this.
Google Earth Comparison
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Orthorectification of Aerial Photo
Premium data use higher resolution photos took from airplane. Those photos need
to be orthorectify in order to overlay the 3d frame. This process rectify distortion
cause by camera len and irregular terrain relief. The photo is resample pixel by pixel from the center
so that each pixel represent the same amount of horizontal meter on the ground.
Original photo
After orthorectification
