Impact of the spacecrafts orbits on LISA data analysis

Gravitational waves are signals coming from massive and compact distant sources. Their detection is a unique opportunity to understand their physics. LISA (Laser Interferometer Space Antenna, a collaboration between ESA and NASA) is a constellation of three satellites which will be able to detect gravitational waves by interferometry after its launch in 2034. The goal of the internship is to determined the sensibility of the detected signal to variation of the constellation geometry. Firstly, the constellation orbits had to be modeled, in order to see their evolution along the mission. Then, monochromatic gravitational waves coming from galactic binaries are modeled, as well as the shape of the signal detected by the LISA constellation. The development of data analysis tools allows to determine, from the detected signal, the characteristic of the gravitational wave source. Finally, systematic errors on geometric variables of the constellation have been added. The analysis of the parameter estimation of the source with these errors, and their comparison to the unperturbed case, lead to preliminary results, allowing to measure the sensibility of the detector.