Buffer generation using Spherical Geometry

Buffering is an important area of spatial analysis in GIS applications. The goal of buffering is to determine a neighborhood around a certain point, line or polygon feature based on some constant or variable distance measure. Major challenges for buffer computation are accuracy and computational complexity. Popular buffer generation algorithms use parallel lines for emulating fixed distance. While this may be true for small distances on surface of earth, but for large distances the lines curve along the spherical surface of the earth. We generate buffer with aid of spherical geometric computations. We reduce the set of line segments for intersection by using a conjoining line segment buffer approach and derive the final buffer by a linear point traversal over all the resulting points. We also use extended concavity tests to address the problem where large buffer size would cause buffer lines corresponding to successive concave input line segments to not intersect.