Local Topographic Model using Position Index for Analyzing the Characteristics of Unserpentinized Lateritic Zones in Sorowako Nickeliferous Laterite Deposit, Indonesia - Wibowo, Setiyo; Post Graduate Program, Faculty of Geology, Padjadjaran University, Jatinangor, Sumedang 45363, Indonesia (International Journal on Advanced Science, Engineering and Information Technology, 2018)