The topographic wetness index (TWI, ln(a/tanβ)), which combines local upslope contributing area and slope, is commonly used to quantify topographic control on hydrological processes. Methods of computing this index differ primarily in the way the upslope contributing area is calculated. In this study we compared a number of calculation methods for TWI and evaluated them in terms of their correl...

This paper addresses the problem of generating digital elevation models from satellite images taken by linear pushbroom cameras. Since there exist unique geometric properties for linear pushbroom images, we argue that the conventional DEM generation schemes developed for perspective images are not suitable for satellite images. Using the geometric properties of linear pushbroom images, we desig...

a r t i c l e i n f o The results of flow-routing methods currently used in the geomorphic literature depend on grid resolution. This poses a problem for landscape evolution models, which must be independent of grid resolution to the greatest extent possible. Here I illustrate a refinement of currently-used flow-routing algorithms that yields unit contributing areas (i.e. contributing areas per...

Digital terrain model (DTM) is one of the important input parameters in urban flood application. This is because it influences the flow direction, flow velocity, flood extend and flood depth. LiDAR offers accurate DTM for large areas within a short period of time. From the overall LiDAR data processes, filtering (classification) poses the greatest challenge. Evaluation and comparison of current...

For true 3D navigation applications that combine terrain data, city models, landmarks, and other 3D geo data, also a real 3D street network is necessary for the route calculations. In this paper we describe how such a network can be derived automatically using detailed digital terrain models. Furthermore a method is described how the terrain model can be enhanced by integrating the roads direct...

The selection of the minimal number of observers that ensures the maximum visual coverage over an area represented by a digital elevation model (DEM) have great interest in many fields, e.g., telecommunications, environment planning, among others. However, this problem is complex and intractable when the number of points of the DEM is relatively high. This complexity is due to three issues: 1) ...

This paper presents the current status of the development of our autonomous blimp project. Details are given on the hardware setup, which is currently almost operational. Some first experimental results on terrain mapping terrain mapping with low altitude stereo imagery are presented and discussed. The approach involves the intregration of several algorithms: stereovision, interest point matchi...

Singhbhum Shear Zone is a highly mineralized zone having variety of minerals, predominantly those of uranium, copper and some sulphide minerals. From Remote Sensing data it is possible to decipher the regional lithology, tectonic fabric and also the geomorphic details of a terrain which aid precisely in targeting of metals and minerals. Mapping of mineralized zones can be done using Geospatial ...

We present a set of procedures to extract useful information from maps of cities in order to help in interpreting aerial images. The aim of this work is to combine semantic information issued from the map with the raw information coming from a picture. Several cues can be extracted from maps. The road network gives the structure of the city and cut the scene in small but coherent regions: the u...