The talk describes an innovative method to simultaneously estimate motion and track a structure on an image sequence. To process noisy images, assumptions on dynamics should be involved. Consequently, the method relies on the dynamics equations of the studied physical system. Promissing results have been obtained on twin experiments in order to quantify the accuracy of the method. The approach has also been tested on satellite acquisitions in order to track clouds an meteorological satellite acquisitions. Further research will concern the conception of a multi-object tracking method.