Direct georeferencing and orthorectification of airborne digital images

Kiracı, Ali Coşkun
GPS/INS (Global Positioning System / Inertial Navigation System) brings possibility of relaxing the demand for aerial triangulation in stereo model construction and rectification. In this thesis a differential rectification algorithm is programmed with Matlab software for aerial frame camera images. This program is tested using exterior orientation parameters obtained by GPS/INS and images are ortho-rectified. Ground Control Points (GCP) are measured in the orthorectified images and compared with other rectification methods according to RMSE and mean error. Besides, direct georeferencing accuracy is investigated by using GPS/INS data. Therefore, stereo models and ortho-images are constructed by using exterior orientation parameters obtained with both aerial triangulation and GPS/INS integration. GCPs are measured in both stereo models and ortho-images, compared with respect to their RMSE and mean error. In order to determine Digital Elevation Model (DEM) effect in ortho-rectification, different DEM data are used and the results are compared.


Wavelet-based outlier detection and denoising of airborne laser scanning data
Akyay, Tolga; Karslıoğlu, Mahmut Onur; Department of Geodetic and Geographical Information Technologies (2008)
The method of airborne laser scanning also named as LIDAR has recently turned out to be an efficient way for generating high quality digital surface and elevation models. In this work, wavelet-based outlier detection and different wavelet thresholding (wavelet shrinkage) methods for denoising of airborne laser scanning data are discussed. The task is to investigate the effect of wavelet-based outlier detection and find out which wavelet thresholding methods provide best denoising results for post-processi...
Real-time snow cover mapping over mountainous areas of Europe using msg-seviri imagery
Sürer, Serdar; Şorman, Ali Ünal; Department of Geodetic and Geographical Information Technologies (2008)
An algorithm has been developed for snow recognition (SR) over mountainous areas of Europe from satellite imagery. The algorithm uses Meteosat Second Generations (MSG) instrument Spinning Enhanced Visible and Infra-Red Imager (SEVIRI) data that are acquired in every 15 minutes through whole day. Although SEVIRI has low spatial resolution, its high temporal resolution provides a better discrimination capacity between ice clouds and snow. Discrimination of snow and clouds is the most challenging part of snow ...
Weighted multi-visibility analysis on directional paths
Şeker, Çağıl; Toprak, Vedat; Department of Geodetic and Geographical Information Technologies (2010)
Visibility analysis is an important GIS tool that is used in a diverse array of disciplines ranging from earth sciences to telecommunications. Multi-visibility, as a cumulative type of visibility, combines many point-to-point results into a multi-value array. Points, lines, or areas can be used as sources or targets; and the combined values can be calculated in both ways. Through multi-visibility, a special 2.5D visibility value surface can be constructed over a digital elevation model. The effectiveness of...
Integration of geophysical - geological data using geographic information systems
Şirinyıldız, Tunç; Toprak, Vedat; Department of Geodetic and Geographical Information Technologies (2003)
This study attempts to integrate geophysical data with other spatial data using Geographic Information Systems (GIS). The study is carried out in a part of Galatean Volcanic Province, north of Ankara. Gravity, magnetic, topographic, rock type and volcanic eruption center data are the data layers used in the study. All data layers are converted to raster format with a grid spacing of 100 m. The first step in the analysis is the pair-wise analyses of all data layers. For the geophysical data, different layers...
Analysis of vision aided inertial navigation systems
Yuksel, Yigiter; Kaygisiz, H. Burak (2006-04-19)
We propose in this paper a method to integrate inertial navigation systems with electro optic imaging devices. Our method is based on updating the inertial navigation system in a Kalman filter structure using line of sight measurements obtained from a camera. The proposed method is analyzed based on a UAV scenario generated by our trajectory simulator and the results are provided here. The results show that even a single vision aid can improve the performance of inertial navigation system.
Citation Formats
A. C. Kiracı, “Direct georeferencing and orthorectification of airborne digital images,” M.S. - Master of Science, Middle East Technical University, 2008.