How can we collect the flight data after a ROS simulation and what kind of dataset do we obtain? Can we get the sensor and video dataset with timestamps to be used in analysis?
As Ben noticed, you may want to elaborate on your question, but in general data collection in ROS is performed using tools from the rosbag package.
As you'll find when you read the documentation, data (either from a simulation or the real world) can be recorded during a session, but not after it has already finished.
Recorded data can be replayed or extracted for analysis on various ways. In particular I recommend you check the API for programmatic manipulation of rosbag files, it includes many useful features, such as recovering message record times (which is very convenient for messages that don't already include a timestamp field).