haku: @supervisor Visala, Arto / yhteensä: 105
viite: 15 / 105
Tekijä:Kumar, Rachit
Työn nimi:Automatic Radiometric Improvement of Moon Images for Shadow Segmentation
Julkaisutyyppi:Diplomityö
Julkaisuvuosi:2015
Sivut:[11] + 67 s. + liitt. 6      Kieli:   eng
Koulu/Laitos/Osasto:Sähkötekniikan korkeakoulu
Oppiaine:Space Robotics and Automation   (AS3004)
Valvoja:Visala, Arto ; Enmark, Anita
Ohjaaja:Lingenauber, Martin
Elektroninen julkaisu: http://urn.fi/URN:NBN:fi:aalto-201509184365
Sijainti:P1 Ark Aalto  3078   | Arkisto
Avainsanat:image processing
optical navigation
shadow segmentation
lunar image classification
Tiivistelmä (eng):Kaufmann et al.
[18] have proposed a method for pose estimation of the space craft during the descent phase by matching the shadows between real time images and reference images.
The shadow segmentation of the real time images is largely affected by the lunar surface reflectance, the lunar surface features and the illumination conditions.
The thesis investigates various radiometric enhancement methods to reduce the effect of these artefacts on the shadow segmentation.
An enhancement pipeline was designed to enhance the contrast of the images.
An automated classification of images was also implemented in the pipeline based on topographical information and mathematical parameters.
The Narrow Angle Camera (NAC) images from Lunar Reconnaissance Orbiter (LRO) mission were used, to develop the automated classification logic of the pipeline using the training data set and to validate the performance of the pipeline using the test data set.
The reference images were rendered from the Digital Terrain Model (DTM) files of the corresponding NAC images.

The result shows that enhancement of the descent images increases the amount of segmented shadows, when compared with the shadow segmented original image.
The percentage of correct shadow match between the shadow segmented virtual image and shadow segmented enhanced images are higher compared to the shadow segmented original image.
Further, it is observed that the applied enhancement method depends on the surface reflectance and the incidence angle.
ED:2015-09-27
INSSI tietueen numero: 52082
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