1204.2125 (Gang Wang et al.)

Numerical simulation of time delay interferometry for NGO/eLISA    [PDF]

Gang Wang, Wei-Tou Ni

NGA/eLISA is a new mission proposal with arm length 106 km and one interferometer down-scaled from LISA (http://elisa-ngo.org/). Just like LISA and ASTROD-GW, in order to attain the requisite sensitivity for NGO/eLISA, laser frequency noise must be suppressed below the secondary noises such as the optical path noise, acceleration noise etc. In previous papers, we have used the CGC 2.7 ephemeris to numerically simulate the time delay interferometry for LISA and ASTROD-GW with one arm dysfunctional and found that they are both well below their respective limits under which the laser frequency noise is required to be suppressed. In this paper, we follow the same procedure to simulate the time delay interferometry numerically. To do this, we work out a set of 1000-day optimized mission orbits of NGO/eLISA spacecraft starting at January 1st, 2021 using the CGC 2.7 ephemeris framework. We then use this numerical solution to calculate the residual optical path differences in the second-generation solutions of our previous papers. The maximum path length difference, for all configuration calculated, is below 12 mm (40 ps). This is well below the limit under which the laser frequency noise is required to be suppressed for NGO/eLISA. We compare and discuss the resulting differences due to different arm lengths for various mission proposals -- NGO/eLISA, an NGO-LISA-type mission with a nominal arm length of 2 \times 10^6 km, LISA and ASTROD-GW.

View original: http://arxiv.org/abs/1204.2125