Identification of Optimal Spatial Resolution with Local Variance, Semivariogram and Wavelet Method – Case Studying Typical Landscape of Mountainous Area in Southeast China
Qiu Bingwen*, Sui Yinbo, Chen Chongcheng and Tu Xiaoyang
Key Laboratory of Spatial Data Mining and Information Sharing of Ministry of Education, Fuzhou University,Fuzhou 350002, Fujian Province, China
Abstract: Understanding the spatial structure of images and selecting optimal spatial resolution has always been an important issue in the application area of remote sensing. The prime objective of this study was to conduct a comparative study of the optimal spatial resolutions for measurement of typical landscape of Mountainous Area in Southeast China, detected with local variance, semivariogram and wavelet analysis. The first principal component of SPOT image was used. The results of local variance demonstrated that optimal spatial resolution of urban, agricultural and forest landscape was around 10-20m, 30-40m and 50-80m respectively. As derived from wavelet transform, it was 40m, 80-160m and 160m respectively. Their values indicated by semivariogram through Exponential and spherical model should be at least less than 160m, 328m and 309m. Although the values we gained from variogram modeling fall within the bound of values derived from wavelet analysis, the values obtained from local variance are relatively small. The values of optimal spatial resolution obtained can vary from the methods and data source we choose and also the prime objects of interest in study areas.
Keywords: Optimal spatial resolution; Landscape; semivariogram; wavelet transform; local variance