The Effect of Polynomial Order on Georeferencing Remote Sensing Images

Abstract

Large area of the world's land surface is not mapped at 1:50,000 scale or better. Satellite remote sensing images provides an up-to-date and cost effective means of producing image maps and derived topographic maps for all areas of the world. In order to do this, satellite image is usually subject to some sort of adjustment -georeferencing- to ground control points. Polynomial equation is one of widely used model for georeferencing such images. This research work was oriented to evaluate the effect of the degree of polynomial order -as one of georeferencing model- on the accuracy of the adjusted satellite image. First, second and third orders of polynomial equation were used to adjust satellite image. Check points were observed and accuracy was evaluated. Two satellite images were tested. One of them was Ikonos satellite imagery of 1m resolution and the other was Landsat5 satellite image of 30m resolution. Results showed that the three orders of polynomial equation used to adjust satellite images produce approximately the same results. Therefore, the use of the first order polynomial equation is sufficiently enough to adjust or georeference satellite images whenever the type of satellite images, rather than to use higher order. The thing that preserves time and money.