A fuzzy approach to visibility maps creation over digital terrains


The construction of inter-visibility models for a terrain is an important tool for environmental and animal studies. EEcient crisp algorithms are known to address this problem directly on a raster digital elevation map (DEM) of the study area. Randomness plays an important role: several factors like vegetation, height of the observer, presence of unmapped human artifacts, etc. cannot be modeled in advance into a traditional DEM model. We propose the use of fuzzy terrain models to incorporate uncertainty and unpredictable variability of the landscape. Accordingly, we propose a suitable deÿnition of visibility to obtain inter-visibility models. An algorithm that uses approximation of fuzzy numbers with a discrete family of intervals is proposed. The proposed model produces sound results and can be extended to model complex situations like trian-gulating a radio source using two directional receivers. All of these situations are diicult to manage with a precise stochastic model and are a frequent occurrence in animal behavior studies under ÿeld conditions. The proposed techniques have been implemented inside a user-friendly software package that may easily exchange data with the most common GISs. We report also some experimental results obtained using over artiÿcial terrain under controlled noise and under-sampling conditions.

DOI: 10.1016/S0165-0114(02)00250-6

Extracted Key Phrases

11 Figures and Tables

Showing 1-10 of 16 references

Uncertain data processing with fuzzy B-splines, Fuzzy Sets and Systems

  • M Anile, B Falcidieno, G Gallo, M Spagnuolo, S Spinello
  • 2000
3 Excerpts

Approximation of Bathimetric Data with FBS. (Poster) SIAM CAGD 97 Conf

  • M Anile, B Falcidieno, G Gallo, M Spagnuolo, S Spinello
  • 1997
1 Excerpt

Implementing fuzzy arithmetic, Fuzzy Sets and Systems

  • M Anile, S Deodato, G Privitera
  • 1995
2 Excerpts

Virtual environment for ocean visualization and exploration

  • M Patrikalakis
  • 1995