Abstract: High-repetition-rate laser target designators (LTD) have proved their usefulness in warfare. The semi-active laser guidance technique has a LTD and precision laser guided bomb (LGB) working together with a unique pattern of laser pulses. This unique pattern or code of laser pulses is programmable through the LTD and is known to its counterpart weapon delivery system before an operation. A weapon’s sensors detect a coded laser spot, which is created by a LTD illuminating the target. The laser spot clearly marks the target to an aerial attacker or guided weapon. The programmable nature of laser pulse repetition rates makes these systems sophisticated, but these systems are also vulnerable to time-dependent instability, which in turn decreases the accuracy of the desired pattern or code. Hence, to assure high effectiveness of these systems, they must be regularly evaluated. This paper describes a system called a Laser Spot Detector (LSD), which evaluates the performance of a LTD by detecting the pulsed laser emitted by the LTD with a pulsed laser source either working in the near-IR or eye-safe range. The pulse repetition frequency (PRF) of a pulsed LTD is set to be its unique PRF code for ongoing missions and thus, an LSD can be effectively used in validating the codes emitted by LTD, thereby enhancing the efficacy of precision-guided munitions.