How to verify the accuracy of gazebo simulation?

My idea is to compare simulation and actual flight output (such as output attitude angle) under the same input (such as the reference Euler angle in attitude mode). So, after an actual flight test, I got the flight log from the SD card. I want to use the control command (such as rc signal) in the sitl to test how close the gazebo simulation is to the real system. How can I modify it? px4?