This article presents an algorithm that determines safe motions for an articulated rover on rough terrains. It relies on the evaluation of a set of elementary trajectories on a digital elevation map built as the rover moves. The algorithm relies on the explicit computation of geometric constraints on the rover chassis. It has been integrated within a continuously running navigation loop on boar...

Hack’s law is reviewed, emphasizing its implications for the elongation of river basins as well as its connections with their fractal characteristics. The relation between Hack’s law and the internal structure of river basins is investigated experimentally through digital elevation models. It is found that Hack’s exponent, elongation, and some relevant fractal characters are closely related. Th...

Catastrophic floods originating from glacial lake outbursts have recently become one of the primary natural hazards in the southeastern Tibetan Plateau. Here we report observations of glacial lake expansions and glacier recessions in the Boshula mountain range, southeast Tibet, derived from multitemporal remote-sensing images and digital elevation models during the period from the 1970s to 2009...

The coastal area is a multi-issue area that promote the production of new data to improve its characterization, including LiDAR surveys (Light Detection and Ranging) for the generation of Digital Terrain Model (DTM) with high spatial resolution. Challenges are located on the integration and the rendering of these data, because of their heterogeneity (images and vectors), but also because curren...

In this paper, we propose a new methodology for extracting river networks from satellite images. It combines morphological generalised geodesic transformations with hydrological overland flow simulations. The method requires the prior generation of a geodesic mask and a marker image by applying a series of transformations to the original image. These images are then combined so as to produce a ...

Land-use dynamics and climatic gradients have large effects on many terrestrial systems. Exurban development, one of the fastest growing forms of land use in the United States, may affect wildlife through habitat fragmentation and building presence may alter habitat quality. We studied the effects of residential development and temperature gradients on bird species occurrence at 140 study sites...

purpose : to report a new familial presentation of hypoplasia and absence of superior rectus in the form of unilateral monocular elevation deficiency case report : a 7-year-old boy was referred to our center (poostchi eye clinic) with a chief complaint of ocular misalignment in his right eye since birth. one of his siblings was a known case of unilateral monocular elevation deficiency and was o...

introduction snow is a kind of precipitation that is formed by the condensation of moist air mass and in the condition that temperature is below freezing point. although small areas of the world are mountainous regions, these small territories play an important role in the hydrological context of river basins. in some areas snow covers and glaciers supply drinking water. monitoring and forecast...