The solar radiation intercepted at a given location on the earth's surface is influenced by surface orientation and sky obstruction by surrounding topographic features. Viewshed models can be used to calculate sky obstruction for any given location on or above a complex topographic surface. We have developed an algorithm for rapid calculation of intercepted solar radiation using a combination o...

To the Editor, The Indian Medical Gazette. Sir,?I was very interested to see the article by mv old friend and brother-officer Lieut -Col. G. G. Jollv who is now Director of Public Health in Burma, in your last issue. His article gives an interesting account of a very common occurrence in connection with deep wells. He observes that under certain climatic conditions there is a decided falling of...

Given a terrain model, the viewshed from a viewpoint is computed as the set of X-Y positions of a point target such that the target is visible. We introduce a novel approach to the computation of accurate viewshed approximations. Our algorithm relies on the computation of an approximation to the so-called line-of-sight (LOS) function. This function is defined over target X-Y positions, and is t...

Preferences for developing 3600 MW offshore wind farms in Denmark are estimated based on data from a choice experiment. The variation willingness to pay the location of power development at 8, 12, 18, or 50 km shore is analysed as function gender, age, education, income, turbine viewshed, and beach visits. With space mixlogit model, we find that varies significantly income level, viewshed farms...

Viewshed analysis, often supported by Geographic Information Systems (GIS), is widely used in many application domains. However, as terrain data continue to become increasingly large and available at high resolutions, data-intensive viewshed analysis poses significant computational challenges. General-Purpose computation on Graphics Processing Units (GPGPU) provides a promising means to address...

introduction conservation and management of landscapes and beautiful sceneries is one of the necessities of establishing and maintaining the protected areas. analysis of landscape visual quality has an important place in landscape planning and designing. in this way, reviewing effective criteria and discovering the simple patterns which affect the landscapes is the most important step of modeli...

The viewshed of a topographic dataset is the region around a given observation point that is visible from that location. Most GIS packages allow its computation. It has many uses, such as in urban environment planning, or in analysing archaeological site data. The viewshed is used here as a data enhancement tool to aid in the interpretation of geophysical potential field data. The fraction of t...

Many interesting application problems on terrains involve visibility computations; for example, the search for optimal locations of observation points, line-of-sight communication problems, and the computation of hidden or scenic paths. The solution of such problems needs techniques to answer visibility queries on a terrain eeciently, and/or the development of data structures encoding the visib...