Observation scheme optimization of geodetic GPS networks based on accuracy and reliability objective functions

Observation Scheme Optimization of Geodetic GPS Networks Based on Accuracy and Reliability Objective Functions Nowadays, with the developments in technology, GPS networks have taken the place of terrestrial networks. As to meet the usage purpose of a geodetic GPS network, it has to be optimized depending on an appropriate objective function in designing stage. The selected objective function should ensure the desired accuracy and reliability values for a GPS network. The selected order design should have the ability of making the objective function values minimum and the selected solution method should be applicable for the order design. In this study, it was aimed to optimize a GPS network based on sessions planning and establish in the Karadeniz Technical University campus and a part of Trabzon airport area. In the course of accuracy optimization of the network, the objective function of A- optimality that leads to a homogenous network and the objective function of E-optimality that leads to increase the points' position accuracy were selected. During the reliability optimization of the network, individual redundancy numbers, internal and external reliability criteria values were selected as the reliability objective functions. As to minimize above-mentioned objective functions, optimization of observation scheme that is named also as first order design was selected. As to realize the above-mentioned order design, sequential least squares method was used as a solution method for the optimization. In designing stage, sessions were planned as if three, four and five receivers were used in the fieldwork. As the result of the study, it was seen that the sessions can be planned more flexible with three receivers than four and five. As a result of the accuracy optimization it was found out that the objective function values of every repeated solution were inversely proportional with the number of the baselines and not linear. As the result of the reliability optimization, it was determined that not only high global redundancy number is adequate to provide a reliable network but also the individual reliability criteria values should be close to each other. In other words, the network should be homogenous with respect to individual reliability criteria. Keywords: Accuracy, Reliability, Optimization, Objective Function, Observation Scheme, Order Design, Solution Method VI