Integration of motion blur into the TTP metric for pilotage performance

Infrared pilotage sensors enhance pilots’ situational awareness, aiding in obstacle avoidance and providing visibility during night flights or under degraded visual environments. Pilotage with a rotorcraft tends to be more difficult than with fixed-wingcraft as rotorcraft generally fly at a lower altitude, which increases the angular velocities of the ground below and other features nearby with respect to the pilotage sensor. This increase in the scene’s angular velocity increases motion blur in the imagery. This increased blur due to integration time, or time constant, lowers the system’s Modulation Transfer Function (MTF), thus reducing the Target Task Performance (TTP) metric. This lower TTP also corresponds to a decrease in the system’s pilotage performance. There has not been a straightforward method for including motion blur in the degradation of the TTP metric for pilotage performance. In this study, data is collected from a helicopter from different perspectives, using well-characterized cameras to capture the two levels of motion blur in pilotage imagery from two different looking angles. The imagery and Inertial Measurement Unit (IMU) data is then used to calculate the amount of angular motion and jitter in milliradians, which is then used to calculate a new degraded MTF and TTP metric. The addition of motion blur into the TTP metric for pilotage is essential in accurately predicting and evaluating the pilotage performance of systems on platforms that are moving quickly and have significant sensor time constant blur.