tailieunhanh - Remote Sensing and GIS Accuracy Assessment - Chapter 15

Công nghệ viễn thám đã nâng cao đáng kể trong những thập kỷ qua. Theo đó, định dạng dữ liệu cảm biến từ xa đã phát triển từ hình ảnh (trước năm 1970) sang các định dạng kỹ thuật số tiếp theo sự ra mắt của vệ tinh (1972), trong một gia tăng của các sản phẩm bản đồ phái sinh. Độ chính xác các sản phẩm này đã trở thành một bước tích phân cần thiết để đánh giá các ứng dụng thích hợp Congalton và Green, 1999). Trong ba thập kỷ qua, đánh giá độ chính xác đã trở thành áp dụng rộng. | CHAPTER 15 The Effects of Classification Accuracy on Landscape Indices Guofan Shao and Wenchun Wu CONTENTS Relative Errors of Area REA .211 Results. .213 Acknowledgments .219 References .219 INTRODUCTION Remote sensing technology has advanced markedly during the past decades. Accordingly remote sensor data formats have evolved from image pre-1970s to digital formats subsequent to the launch of Landsat 1972 resulting in a proliferation of derivative map products. The accuracy of these products has become an integral analysis step essential to evaluate appropriate applications Congalton and Green 1999 . During the past three decades accuracy assessment has become widely applied and accepted. Although methodologies have improved little attention has been given to the effects of classification accuracy on the development of landscape metrics or indices. Thematic maps derived from image classification are not always the final product from the user s perspective Stehman and Czaplewski 1998 . Because all image processing or classification inevitably introduces errors into the resultant thematic maps any subsequent quantitative analyses will reflect these errors Lunetta et al. 1991 . Landscape metrics are commonly derived from remote sensing-derived LC maps O Neill et al. 1988 McGarigal and Marks 1994 Frohn 1998 . Metrics are commonly used to compare landscape configurations through time or across space or as independent variables in modeling linking spatial pattern and process Gustafson 1998 . Therefore conclusions drawn directly or indirectly from analyzing landscape metrics contain uncertainties. The relationships between the accuracy of LC maps and specific derived landscape metrics are 209 2004 by Taylor Francis Group LLC 210 REMOTE SENSING AND GIS ACCURACY ASSESSMENT quite variable . metric dependent which complicates assessment efforts Hess 1994 Shao