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GIS (Fach) / GIS (Lektion)
- Discrete Return LIDAR ? •Records data as X,Y,Z points •Spatial resolution is expressed in terms of “post spacing” which is the avg. horizontal distance between points •However, you can have multiple returns within the same pulse •Returns are “triggered” if the laser reflects from a surface large enough to exceed a pre-set energy threshold •New capability to record the intensity of point returns.
- RADAR Fernerkundung? Radar= Radio detection and ranging (Funkmessverfahren) Grundprinzip= aktive Beleuchtung und Erfassung des Echosignals Kernaufgaben: - sind Ziele vorhanden, (detection) wenn ja wie viele?- wo und in welcher Entfernung (ranging) befinden sich diese Ziele ? Es lassen sich weitere interessante Objektmerkmale erfassen zB:- Rückstreuquerschnitt, Objektgeometrie, GeschwindigkeitJe nach Aufgabe werden gemessen:- Amplitude, Phase und Polarisation des Signals
- Convolution Filters? •Underlying operation in a convolution filter is the use of a moving window on the image •An operation is performed within the window – a calculated value is put in the output image, usually the same location as the center of the window in the input image •(window moves to next pixel...) •Convolution is one of the most useful tools in image processing
- Image Fusion ? In the fused output, spectral signatures of the input color image and spatial features of the input pan image, as the best attributes of both inputs, are (almost) retained. The spectrally and spatially enhanced image is often visually appealing, starting to compete with high-resolution aerial photographs.
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