GPI 2.0 : optimizing reconstructor performance in simulations and preliminary contrast estimates

During its move from the mountaintop of Cerro Pachon in Chile to the peak of Mauna Kea in Hawaii, the Gemini Planet Imager will receive various upgrades, including a pyramid wavefront sensor. As a non-linear sensor, a standard approach to linearize the response of the pyramid is induce a rapid circular modulation of the beam around the pyramid tip, trading off sensitivity for robustness during high turbulence. Using high temporal resolution Fourier Optics based simulations, we investigate phase reconstruction approaches that attempt to optimize the performance of the sensor with a dynamically adjustable modulation parameter. We have studied the linearity and gain stability of the sensor under different modulation and seeing conditions, and the ability of the sensor to correct non-common-path errors. We will also show performance estimates which includes a comparative analysis of the atmospheric columns above the two mountains, as well as the Error Transfer Function of the two systems.