How to obtain the true and estimated values for evaluation?

[hsiaochao]

Hello, how did you obtain the true and estimated values for evaluation? I have some questions about it:
1.My understanding is that the estimated value is in the following code
'''
//Update global TF
Tf: Quaternion q;
q. SetRPY (m roll, m pitch, m yaw);
M_ LastGlobalTf=tf:: Transform (q, tf:: Vector3 (tx, ty, tz)) * odomTf. inverse();
'''
the estimated value is concluding tx, ty, tz, q.
Is it like this?
2. The true value of the catec1 sequence is in the topic "/ground_truth/pose" of the bag file, but fixed difference id between the timestamp of the timestamp of "/ground_truth/pose" and the timestamp of "/lidar_pointcloud". What is the specific difference?
3.How to obtain the true value of airsim1 sequence? What topic is it?

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