Design of High-precision Timing System for Detonation Point Measurement

With the rapid development of modern weapon systems， high-precision measurement of explosion timing has become a key factor in evaluating weapon effectiveness and supporting tactical decision-making. To address the limitations of existing detonation timing measurement systems—such as inadequate accuracy， limited detection capability， and high cost，this paper presents the design of a high-precision explosion timing measurement system. The proposed system is capable of accurately capturing the instant of projectile detonation， providing a unified time reference for various test-range measurement and control instruments such as high-speed cameras and theodolites. It further supports the analysis of explosion parameters and damage assessment， enabling rapid localization of explosion timing points within large-scale datasets.The system consists of five major components　an optical signal acquisition and conversion circuit， an analog signal amplification module， a digital processing core， an analog-to-digital conversion subsystem， and a GPS timing unit. In the optical detection stage， a silicon photodiode BPW20 with a peak sensitivity at 920 nm is selected and paired with an AD825 transimpedance amplifier to perform photoelectric signal acquisition and initial amplification. This configuration offers low dark current and low noise voltage， ensuring stable operation under high signal-to-noise ratio conditions. To further enhance long-range detection capability， a condenser lens optimized using Zemax was incorporated into the optical structure， significantly improving the convergence of incident light. Experimental results show that the addition of the condenser lens increases detection capability by approximately ninefold.To improve timing accuracy， the system adopts a GPS-disciplined local clock architecture， using the 1 PPS signal as the reference. Through hardware-software co-design， the system obtains and maintains synchronization with the GPS time base. An initial time offset of about 7 μs was observed； to eliminate this error， an All-digital Phase-locked Loop （ADPLL） structure was integrated. By employing phase detection and a PI adaptive regulation mechanism， the local clock is precisely aligned with the 1 PPS signal. Oscilloscope measurements after synchronization indicate that the residual timing error is less than 50 ns， thereby achieving high-precision timekeeping based on a standard crystal oscillator while effectively reducing system cost.In indoor simulation experiments， the system successfully captured transient LED emissions within a range of 5~30 m， verifying its sensitivity and timing accuracy. In outdoor field tests， the system effectively detected the flash produced by firecracker explosions at distances beyond 100 m and accurately recorded the time corresponding to the optical intensity peak. Comprehensive experimental results demonstrate that the proposed system provides precise， real-time， and reliable detection of explosion light and timing， meeting the requirements of modern test-range applications and showing broad engineering potential.Future research will focus on system miniaturization and low-power design to enable deployment on mobile platforms such as UAVs， thereby extending its applicability within modern test-range systems.