## 1 Introduction  
Pulse scanning light detection and ranging (LIDAR) measures the distance to a given object using a time-of-flight (ToF) technique that measures the time required for a pulse to transmit to and reflect off the object [1; 2; 3; 4; 5; 6]. The distance image of the surroundings can be generated with excellent angular resolution, and is used to determine the area that can be traveled while mounted on an autonomous vehicle or an autonomous mobile robot. Many factors determine the operating characteristics of pulse scanning LIDAR, and can be divided into the characteristics of the transmission and generation of a pulse, and those of the reception of a reflected pulse [3; 7; 8]. In the transmitter, the pulse scanning LIDAR determines the wavelength of the laser as well as the pulse width, interval, and peak power [9]. In the receiver, it determines the size of the receiving aperture and uses a photodetector, a pulse detection method, the threshold-to-noise ratio (TNR), and a range estimation method [10; 11; 12; 13]. The characteristics used to generate pulses in the transmitter are limited by the maximum permissible exposure (MPE) to comply with eye safety standards [14]. The most critical parameter that determines the maximum measurement distance in LIDAR is the pulse peak power of the transmitter and the TNR of the receiver. As the strength of the received signal is proportional to the peak power of the pulse and inversely proportional to the square of the measured distance, the higher the pulse peak power and the lower the TNR, the greater the distance that can be measured. Thus, if the characteristics of one parameter are improved, the characteristics of the other parameters worsen [9]. Depending on the primary purpose of LIDAR, one or two of the parameters are used as characteristics of preference, and the remaining are rendered MPE-compliant. For pulsed, amplitude-modulated continuous wave (AMCW), and frequency-modulated continuous wave (FMCW) LIDAR, the maximum measurable range \(R\) depends on the ToF measurement techniques as follows:  
\[R= \begin{cases}c\frac{T}{2\lambda}&\text{for a pulsed LIDAR}\\ c\frac{\phi}{4\pi T}&\text{for an amplitude-modulated continuous wave LIDAR}\\ c\frac{B}{2\lambda}&\text{for a frequency-modulated continuous wave LIDAR}\end{cases}  \tag{1}\]  
where \(c\) is the speed of light, \(T\) is the pulse repetition period of the pulsed LIDAR, \(\phi\) is the phase shift between the transmitted and reflected signal, \(f\) is the modulation frequency of the AMCW LIDAR, \(B\) is the frequency sweep bandwidth of FMCW LIDAR, and \(\lambda\) is the frequency shift per unit of time [2,4,5]. \(T\) limits the maximum range of the pulsed LIDAR, \(\phi\) and \(f\) limit the maximum range of the AMCW LIDAR, and \(B\) and \(\lambda\) limit the maximum range of FMCW LIDAR. The main drawback of pulsed scanning LIDAR is that its maximum measurable range is proportional to the maximum pulse repetition period, and high-angular-resolution scanning is only possible at low revolutions per second. In pulsed scanning LIDAR, we can measure the target distance at greater than 100 m with a pulse repetition period higher than 0.666 us using Equation (1). For these scanning LIDAR, we can calculate the minimum range resolution \(\delta R\) by the following equation [9,15]. \[\delta R= \begin{cases}c\frac{1}{2W}&\text{for a pulsed LIDAR}\\ c\frac{1}{2\phi}&\text{for an amplitude-modulated continuous wave LIDAR}\\ c\frac{1}{2\beta}&\text{for a frequency-modulated continuous wave LIDAR}\end{cases}  \tag{2}\]  
where \(W\) is the pulse width of the pulsed LIDAR, \(\phi\) is the phase shift of the AMCW LIDAR, and \(B\) is the frequency sweep bandwidth of the FMCW LIDAR. The range resolution is the ability to distinguish the reflections from two targets that are very close in range. The time difference \(\delta t\) between the reflections from two targets is proportional to the range resolution.