Abstract
Abstract. Tree height is a fundamental parameter for describing the forest situation and changes. The latest development of automatic Digital Surface Model (DSM) generation techniques allows new approaches of forest change detection from satellite stereo imagery. This paper shows how DSMs can support the change detection in forest area. A novel region based forest change detection method is proposed using single-channel CARTOSAT-1 stereo imagery. In the first step, DSMs from two dates are generated based on automatic matching technology. After co-registration and normalising by using LiDAR data, the mean-shift segmentation is applied to the original pan images, and the images of both dates are classified to forest and non-forest areas by analysing their histograms and height differences. In the second step, a rough forest change detection map is generated based on the comparison of the two forest map. Then the GLCM texture from the nDSM and the Cartosat-1 images of the resulting regions are analyzed and compared, the real changes are extracted by SVM based classification.
Highlights
Forest management and observation is an important and timeconsuming task
The region based forest change detection method is relied on the following assumptions (Desclee, 2006): i)
This paper, two first order texture features and six Grey Level Co-occurrence Matrix (GLCM) based second order texture features are calculated based on both panchromatic data as well as normalized DSM (nDSM)
Summary
Besides in-situ inspection, in the last years, numerous change detection methods using remote sensing with different kinds of images have been used for forest monitoring (Bruzzone, 1997; Johnson, 1998; Lu, 2004; Mas, 1999). These studies are mainly focused on using IKONOS; SPOT HRV, TM/ETM+ or airborne images. Multi-spectral based colour analysis is one of the most important methods to get the final monitoring results in forest areas These methods are not practicable for Cartosat-1 imagery, which was launched by the Indian Space Research Organisation in 2005, with 2.5 meter spatial resolution stereo images but relatively low spectral information, only one panchromatic channel is available. This offers further possibilities for Cartosat-1 image analysis and applications
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have