Preamble pulse based LiDAR systems and methods

A LiDAR method comprising:

• emitting, by a radiation source, light pulses towards a region of interest (ROI);
• detecting, by a detector, light pulses reflected from the ROI;
• causing, by a processor communicatively coupled to the radiation source, the radiation source to emit a preamble light pulse having an energy EP and a pulse width W1 towards the ROI;
• determining, by the processor communicatively coupled to the detector, if the preamble light pulse is detected by the detector and whether there is an object in the ROI;
• responsive to a determination that if there is an object in the ROI, causing, by the processor, the radiation source to emit a scanning light pulse having an energy EL and a pulse width W2 towards the ROI;
• responsive to the determination that if there is no object in the ROI, causing, by the processor, the radiation source to emit a scanning light pulse having an energy EH and the pulse width W2 towards the ROI;
• and
• waiting for a predetermined duration to determine if the preamble light pulse is detected by the detector, the predetermined duration being calculated based on a preamble distance, the preamble distance being calculated based on a Peak Admissible Exposure Limit (AELpeak per pulse), the width W2, and a repetition frequency f of the light pulses.