Data Format of Trajectory in Future Localization Dataset

Hello,

Can someone please explain the data format of the trajectory in the Future Localization dataset? There is no information on what t_n or b is in the example provided below:

[up.x up.y up.z] TrajLength(n) [t_0 C_0.x C_0.y C_0.z b b] [t_1 C_1.x C_1.y C_1.z b b] … [t_n …]

Additionally, could someone explain how the trajectory relates to the camera frame?

Thanks in advance!