Experimental Technology and Management

距离分辨差分吸收激光雷达(DR-DIAL)能够以高空间分辨率探测不同距离处的气体浓度。2μm波段具有丰富的CO₂吸收线，基于DR-DIAL可以实现对CO₂气体浓度廓线的高精度测量。但2μm波段DR-DIAL系统构建成本高，相关教学实验难以开展。为解决此问题，该文开发了基于MATLAB图形用户界面的2μm波段CO₂气体DR-DIAL教学仿真模拟平台，允许学生自定义各项模型参数，直观地观察吸收截面的选取和校正、回波信号的计算和模拟以及气体浓度廓线的反演过程。该平台操作简单，易于调试，支持自主学习和拓展开发，有助于学生快速了解DR-DIAL系统，并逐步加深对其工作原理与应用的理解。

[Objective] Distance-resolved differential absorption lidar(DR-DIAL) is an advanced active remote sensing technology that provides detailed information on gas distribution and emission patterns by measuring the absorption differences of lasers at different wavelengths by gas molecules. DR-DIAL operating in the 2 μm band features high-precision retrieval of the CO₂ concentration profile and plays an important role in greenhouse gas detection, benefiting from abundant CO₂ absorption lines in this band. However, the stringent experimental requirements of DR-DIAL systems pose challenges for traditional laboratory-based teaching. To address this, a teaching simulation platform was developed using the MATLAB graphical user interface(GUI). This platform not only provides a virtual experimental environment but also enhances student understanding of DR-DIAL system working principles and applications through intuitive visualization and interaction. [Methods] This paper provides a comprehensive overview of DR-DIAL working principles, including laser emission, signal transmission, reception, and data acquisition and processing. Based on these principles, the modelling process for DR-DIAL is elaborated, including the gas model, atmospheric model, and system model. The MATLAB App Designer was used to implement these DR-DIAL models, leading to the development of a MATLAB GUI-based simulation platform for 2 μm band CO₂ DR-DIAL teaching. The platform enables students to independently adjust experimental parameters and interactively observe simulated lidar echo signals and the retrieval of gas concentration profiles. Through this interactive environment, students can gain a comprehensive understanding of the entire workflow, from signal generation to concentration retrieval, fostering a deeper grasp of the underlying principles. [Results] The simulation platform demonstrates 2 μm band laser detection of CO₂ as a case study to showcase the practical applications of DR-DIAL. It allows students to customize various model parameters for specific experiments, enabling them to observe key processes such as absorption cross-section selection and calibration, lidar echo signal calculation and simulation, and gas concentration profile retrieval. Furthermore, the platform provides data storage capabilities, allowing students to conduct multiple experiments and compare their results for further analysis. The entire workflow is demonstrated through a predefined experimental scenario. Experimental results show that retrieved gas concentration values exhibit minimal deviation from the predefined values, validating the platform's effectiveness as a teaching and experimental tool. [Conclusions] The simulation platform is user-friendly, easy to debug, and supports autonomous learning and extended development. These features facilitate students' rapid comprehension of CO₂ DR-DIAL systems and enable a progressively deeper understanding of both operational principles and practical applications by providing practical experience in a virtual environment, thereby facilitating personalized learning and stimulating interest in DR-DIAL technology. Beyond its educational value, the platform serves as a reference for researchers developing DR-DIAL simulation platforms for various wavelengths and gases. It contributes to the broader dissemination and advancement of DR-DIAL technology, offering significant educational benefits and promising application prospects.