Urban Area Extraction Using Airborne X-Band Fully Polarimetric Pi-Sar2 Imagery

Abstract

Commission I, III, VII WG I/2, ICWG III/VII KEY WORDS: PiSAR-2, Urban area, VHR SAR, Fully polarimetric SAR ABSTRACT:In this paper, we present a method to extract urban areas from X-band fully polarimetric synthetic aperture radar (SAR) data. It is known that very high resolution (VHR) SAR can extract buildings, but it requires more processes to map urban areas that should include other objects. The proposed method is mainly composed of two classifications. One classification uses total power of scattering and volume scattering derived by using four component decomposition method with correction of the polarization orientation angle (POA) effect. The other classification uses polarimetric coherency between SHH and SV V . The two results are intersected and final urban areas are extracted after post-classification processing. We applied the proposed method to airborne X-band fully polarimetric SAR data of Polarimetric and Interferometric Airborne Synthetic Aperture Radar System (Pi-SAR2), developed by the National Institute of Information and Communications Technology (NICT), Japan. The validation show that the results of the proposed method were acceptable, with an overall accuracy of approximately 80 to 90% at 100-m spatial scale.

Comparison of urban areas extracted by using L-band and X-band fully polarimetric SAR images

“…Urban areas extracted in study area 1 (left), area 2 (middle) and area 3 (right). (a)(b)(c) ALOS/AVNIR-2 images, (d)(e)(f) urban areas extracted from PALSAR images by using the method by [1], (g)(h)(i) urban areas extracted from Pi-SAR2 images by using the method by [2], and (j)(k)(l) urban areas extracted from Pi-SAR2 images by using the method by [3]. Each panel has an area of 6 km 6km.…”

“…Accuracy of extracted urban areas in (a) study area 1, (b) area 2 and (c) area 3. Pi-SAR2(1) and Pi-SAR(2) denote the results obtained by using the method by [2] and the method by [3], respectively. Figure 1.…”

“…The method by [2] utilizes the randomness of POA in mountains to discriminate them from urban areas. Some mountains and vegetation in Figure 1(e) were not removed because they show relatively homogeneous POA randomness.…”

“…We used a method proposed by Susaki and Kishimoto [2] to extract urban areas in X-band SAR images, and the summary is introduced. The method follows a part of the method by [1], and TP and Pv are used for the first classification.…”

“…Synthetic aperture radar (SAR) has potential to monitor urban areas because man-made structures return relatively strong backscattering to distinguish from other objects and because it is much less sensitive to cloud contamination than optical sensors. In previous papers [1][2], we have proposed methods to extract urban areas using Lband and X-band fully polarimetric SAR images, respectively. In this paper, we compare the results of the urban areas extracted by using the two methods and another existing method [3].…”