Cálculo de área de poligonais geodésicas ou loxodrômicas sobre o elipsóide do Sistema Geodésico WGS-84.

Abstract

The area calculation of geodetic polygonal is a compelling mathematical challenge. How could one calculate the area of a polygon over the ellipsoid, if the sides do not have known parameterization? Some works have already been developed in order to solve this problem, employing mostly equivalent projective systems or authalic spheres approaches. Such methods near the ellipsoidal reference surface by other of easier mathematical treatment, but have limited employment, for a single surface cannot be used for the entire planet, without compromising the calculations over it. In the Code of Civil Procedure, Book IV, Title I, Chapter VIII, Section III, Article 971 says, in its sole paragraph, that "if there is no objection, the judge shall determine the division of the geodesic property . Besides this, there is the Law 10.267/2001, which regulates the requirement for effective registration, that the vertices defining the boundaries of the farms should have their geo-referenced coordinates to Brazilian Geodetic System (BGS), and areas of buildings less than four modules have guaranteed tax-free financial costs. This paper aims to provide a methodology of area calculation for traverses delimited by geodetic lines, or rhumb lines, directly on the ellipsoid, and provide a program that executes routines developed on this work. Since most geodetic surveys are developed using GPS equipment, the data input is based on (X, Y, Z) coordinates, using WGS-84 datum, providing the geodetic area without needing a GIS product. In order to achieve the paper objective, it was developed a different parameterization from the classical geometric Geodesy approach, to transform (X, Y, Z) coordinates into geodetic ones.