Continuously Tracking and storing 6D pose of an object in Gazebo simulation.

Hi, I am currently working on a drone related project and using gazebo for simulation In order to measure accuracy of my localisation, I need to know the **ground truth** values. Is there some way in Gazebo to **continuously track/store** the actual/true/ground truth 6D pose, ie the rotation and translation w.r.t. to a fixed frame like the world frame. I wish to create something like the following -  Thanks a lot !