  The MICROSCOPE space mission aims at testing the Equivalence Principle (EP)
with an accuracy of $10^{-15}$. The test is based on the precise measurement
delivered by a differential electrostatic accelerometer on-board a drag-free
microsatellite which includes two cylindrical test masses submitted to the same
gravitational field and made of different materials. The experiment consists in
testing the equality of the electrostatic acceleration applied to the masses to
maintain them relatively motionless at a well-known frequency. This high
precision experiment is compatible with only very little perturbations.
However, aliasing arises from the finite time span of the measurement, and is
amplified by measurement losses. These effects perturb the measurement
analysis. Numerical simulations have been run to estimate the contribution of a
perturbation at any frequency on the EP violation frequency and to test its
compatibility with the mission specifications. Moreover, different data
analysis procedures have been considered to select the one minimizing these
effects taking into account the uncertainty about the frequencies of the
implicated signals.
