State estimation and fix of an AUV in real time

The GESMA is working on a research project to increase the autonomy of an autonomous underwater vehicle (AUV) in order to realize a complete and important mission without human support. So that the AUV can know its position with precision, two modules are developed. The first one is a state estimator which fuses the data coming from traditional navigation sensors (Doppler, echo-sounder, motion reference unit). The limit of this module concerns the impossibility of carrying out long time missions because of the drift in position which becomes too large after a few minutes or a few hours. We thus added a second module, a state generator which uses the data coming from the sonars and a feature map database to make a fix