Data structure question of tutorial code

Hi, everyone. I have a question about the data structure in the script ‘anymal_c_env.py’.
As I want to customize my Env file, I follow this script and find the total length of observation space is more than 48 as defined.
Here is the code:

observation_space = 48

def _get_observations(self) → dict:
self._previous_actions = self._actions.clone()
height_data = None
if isinstance(self.cfg, AnymalCRoughEnvCfg):
height_data = (
self._height_scanner.data.pos_w[:, 2].unsqueeze(1) - self._height_scanner.data.ray_hits_w[…, 2] - 0.5
).clip(-1.0, 1.0)
obs = torch.cat(
[
tensor
for tensor in (
self._robot.data.root_lin_vel_b,#3
self._robot.data.root_ang_vel_b,#3
self._robot.data.projected_gravity_b,#3
self._commands,#3
self._robot.data.joint_pos - self._robot.data.default_joint_pos,#12
self._robot.data.joint_vel,#12
height_data,#1
self._actions,#12
)
if tensor is not None
],

        dim=-1,
    )
    print("root_lin_vel_b is:", self._robot.data.root_lin_vel_b.size(), end='\n')
    print("root_ang_vel_b is:", self._robot.data.root_ang_vel_b.size(), end='\n')
    print("projected_gravity_b is:", self._robot.data.projected_gravity_b.size(), end='\n')
    print("_commands is:", self._commands.size(), end='\n')
    print("joint_pos is:", self._robot.data.joint_pos.size(), end='\n')
    print("joint_vel is:", self._robot.data.joint_vel.size(), end='\n')
    print("height_data is:", height_data.size(), end='\n')
    print("_actions is:", self._actions.size(), end='\n')
    observations = {"policy": obs}
    return observations

/////////////////// print result
root_lin_vel_b is: torch.Size([4096, 3])
root_ang_vel_b is: torch.Size([4096, 3])
projected_gravity_b is: torch.Size([4096, 3])
_commands is: torch.Size([4096, 3])
joint_pos is: torch.Size([4096, 12])
joint_vel is: torch.Size([4096, 12])
height_data is: torch.Size([4096, 187])
_actions is: torch.Size([4096, 12])

The column length of height_data is so large 187. I want to know how does the script deal with the overlength tensor, regarding the limitation of ‘observation_space’.
I appreciate much your help.

Thank you for your interest in Isaac Lab. To ensure efficient support and collaboration, please submit your topic to Isaac Lab’s GitHub repo following the instructions provided on Isaac Lab’s Contributing Guidelines regarding discussions, submitting issues, feature requests, and contributing to the project.

We appreciate your understanding and look forward to assisting you.