In moving mode, the ______________ is used to determine the patrol speed.

In moving mode, the determination of the patrol speed is achieved using Low Doppler. This is because in moving mode, the radar or lidar device is monitoring the speed of both the target vehicle and the patrol vehicle simultaneously. The Low Doppler setting is specifically designed to measure the speed of the patrol vehicle as it travels, allowing the officer to calculate the relative speed between the patrol car and the target vehicle accurately.

In contrast, High Doppler is primarily used for measuring the speed of an object approaching the radar or lidar unit when it is stationary and is not typically associated with calculating the patrol speed in moving mode. Fixed Doppler deals with stationary modes and does not apply to moving enforcement scenarios. Average speed, although relevant in some contexts, does not directly relate to the specific method of determining the speed of the patrol vehicle in real-time while in motion. Thus, Low Doppler is the correct choice for measuring patrol speed in moving mode.