How to Decide the Best Fuzzy Model in ANFIS

Geoid height determination is one of the major problems of geodesy because usage of satellite techniques in geodesy isgetting increasing. Geoid heights can be determined using different methods according to the available data. Soft computing methods such as Fuzzy logic and neural networks became so popular that they are used to solve many engineering problems. Fuzzy logic theory and later developments in uncertainty assessment have enabled us to develop more precise models for our requirements. In this study, How to construct the best fuzzy model is examined. For this purpose, three different data sets were taken and two different kinds (two inpust one output and three inputs one output) fuzzy model were formed for the calculation of geoid heights in Istanbul (Turkey). The Fuzzy models results of these were compared with geoid heights obtained by GPS/levelling methods. The fuzzy approximation models were tested on the test points.