Preparing WorldView2 Imagery for Map Updating Projects – Aldjyl/ Aleibayiji (Iraq/ North Baghdad) as a Case Study

Abstract

In the presented study, a WorldView2 WV2 satellite image has been prepared to be used in map updating projects. The performed operations can be classified into two categories, the first category includes pansharpening methods for creating a new 8- spectral bands of WV2 Imagery, each one of them has a 0.5-meter spatial resolution. The Pansharpening technique has been implemented with four different approaches, i.e. (Principal Components PC, Wavelet Transform WT, Hyperspherical Color Space HCS, and High Pass Filtering HPF). For these four methods and based on a visual comparison among the quality of the resulting images (with respect to the original Multi-spectral Worldview2 MS-WV2 image), the HCS image has been determined as the best one of them. Because of the high-security situation of the study area, and the impossibility of using the Global Positioning System GPS and other surveying devices there, the Controlled Image Based CIB of 1-meter resolution has been depended on as a source of reference Ground Control Points GCPs. Initially, set GCPs and Check Points are determined on both the HCS Pansharpened image and the CIB image. For maintaining the linearity of the geometric distortion within WV2 original image, the 1st order polynomial transformation model has been selected to perform the geometric correction process. It is clearly concluded that the resulted Root Mean Square Error RMSE of the geometric correction process is acceptable for a wide range of mapping applications. Moreover, the resulting geometrically corrected pan-sharpened WV2 image can be utilized for increasing the interpretation capability of the land features by giving more false color displaying options, and finally supporting the related map updating projects.

Keywords

• worldview2 image
• pansharpening
• geometric correction
• controlled image based