Annual modulation of the galactic binary confusion noise background and LISA data analysis

We study the anisotropies of the galactic confusion noise background and its effects on LISA data analysis. LISA has two data streams of gravitational wave signals relevant for the low frequency regime. Because of the anisotropies of the background, the matrix for their confusion noises has off-diagonal components and depends strongly on the orientation of the detector plane. We find that the sky-averaged confusion noise level √S(f) could change by a factor of 2 in 3 months and would be minimum when the orbital position of LISA is around either the spring or autumn equinox.