Adding noise to P3DX model

Hi Ros users: I am trying to add gaussian noise to velocities of P3DX. The model that I am using is from this source https://github.com/RafBerkvens/ua_ros_p3dx I have modified this part of code: true100.0base_link${ns}/base_pose_ground_truth0.01map0 0 00 0 010 10 10 I change the part where it says "gaussiannoise nad velocityGaussianNoise" but it works in the same way. Does anybody know how i can add gaussian noise to P3DX model?? Thank you so much.