ERROR ESTIMATION OF ORTHORECTIFICATION OF SMALL SATELLITE IMAGES BY DIFFERENTIAL SENSITIVITY ANALYSIS
By using differential sensitivity analysis, horizontal and vertical accuracy of orthorectification of monoscopic images taken by small satellites without using Ground Control Points (GCP) is predicted. The analysis is performed by differentiating the colinearity equation of orthorectification procedure with respect to the satellite’s interior and exterior parameters, elevation obtained from digital elevation model (DEM) and satellite velocity. In addition to this, error of registered imaging time is estimated and the contribution of this error is also taken into account. Square of the differential equations with respect to parameters are multiplied by the variance covariance matrix of the parameters and horizontal uncertainty of the orthorectification is obtained by summing the results of this multiplication. Vertical uncertainty is caused by the uncertainty of DEM and the uncertainty of the horizontal position. Vertical uncertainty caused by the horizontal uncertainty is predicted by estimating a trend by generating a surface polynomial from DEM on the basis of covariance function of Hirvonen. Contribution of each error source is illustrated and the most sensitive parameter is obtained. Analysis results revealed that camera attitude and the image acquisition time are the most important parameters and special weight should be given in order to minimize the uncertainty of the orthorectification in the most efficient way.
 Bettemir Ö. H., “Differential Sensitivity Analysis for the Accuracy Estimation of Orthorectification of Small Satellite Images”, Proceedings of the International Workshop on Small Satellites, New Missions and New Technologies SSW 2008, June 05 – 07, 2008, İstanbul Turkey.
 Bettemir Ö. H., “Differential Sensitivity Analysis for the Orthorectification of Small Satellite Images”, Proceedings of the 4th International Conference on Recent Advances on Space Technologies, RAST 2009, June 11 – 13, 2009, İstanbul Turkey.
 Karl Krauss, “Photogrammetry Volume 1 Fundamentals and Standard Processes” Dümmler 1993 Bonn
 http://www.uzay.tubitak.gov.tr/ visited on: 16.07.2010
 J. C. Helton, “Uncertainty and Sensitivity Analysis Techniques for use in Performance assessment for Radioactive Waste Disposal”, Reliability Engineering and System Safety 42, 1993.
 Jet Propulsion Laboratory, Califormia Institude of Technology, http://www2.jpl.nasa.gov.tr/srtm/srtmBibliography.html visited on September 2006.
 Terma Space www.terma.com visited on June 2010.
 R. Zenick, T. J. McGuire, “Lightweight low-power coarse star tracker”, 17th Annual AIAA/USU Conference on Small Satellites, 2003.
 O. Montenbruck, M. Garcia-Fernandez, J. Williams, “Performance comparison of semicodeless GPS receivers for LEO satellites”, GPS Solut (2006) 10: 249 – 261.
 C. C. Liebe, “Accuracy performance of star trackers – A Tutorial”, IEEE Transactions On Aerospace and Electronic Systems Vol. 38No. 2 April 2002 p. 587 – 589.
 C. C. Liebe “Star trackers for attitude determination”, IEEE AES Systems Magazine, June 1995 p. 10 – 16.
 Hirvonen R. A., “On the statistical analysis of gravity anomalies. Publications of the institute of the International Association of Geodesy, Vol 37 1962, Helsinki.
 Hoffmann-Wellenhof B. and Moritz H., “Physical Geodesy”, Second Edition, Springer Wien, 2006 New York.
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