Airborne Laser Sensing: A suitable tool for disaster management
Abstract
Estimation of damages caused by a disaster is a major task in the post disaster mitigation process. To enhance the relief and rescue operation in the affected area it is required to get a near real time damage model. For this purpose a fast method of data acquisition with suitable methods for extracting the man-made objects are required. Laser scanning data provides the height of the ground objects, which can be used for developing models to extract the man-made features in a complex urban environment. The height variation along the boundary of trees is more significant than buildings; this parameter can be used for their classification. Segmentation of the objects was a preliminary step, where each object, which is standing above a particular height, are segmented. In the next step the contour corresponding to each segmented object was extracted. To classify these polygons into tree or building Modified Standard Deviation (SD) was determined with respect to a best fit line in the local domain i.e. calculating MSD of a sma ll number of consecutive boundary pixels at a time. Since the MSD method is a pixel based classification, so the tree part of a mixed segment can be removed in this process, which is a difficult task in the polygon based classification. Some to the tree parts were remained in the result due to their less height variation. But these can be further removed by analyzing the shape of the resulted polygons. This information can be combined with others like the vulnerability of the area to the disaster, population of the area etc. to generate a pre disaster database. After the disaster, from these specific areas where the buildings were identified in the pre disaster database, modeling of buildings should be done. The building modeling deals with generating the three dimensional models, which will provide the post disaster database. Comparing the post disaster database with the previous one the type and amount of damage can be calculated.
- Publication:
-
34th COSPAR Scientific Assembly
- Pub Date:
- 2002
- Bibcode:
- 2002cosp...34E1941D