多系统广播电离层模型精度评估

电离层误差是导航定位主要的误差源之一，广播电离层模型为单频用户修正电离层延迟提供了简便有效的方法。本文采用CODE提供的GIM产品作为评估的基准，对4大广播电离层模型进行了多方面精度评估，旨在为后续的模型改进及应用提供参考。结果表明：各个模型北半球改正率高于南半球，白天改正率高于晚间；NeQuick模型在中低纬度服务性能一般，但在高纬度地区明显高于BDSK8、GPSK8模型，改正率高出BDGIM模型约5%，BDSK8、GPSK8、BDGIM模型在中低纬度改正率较高，高纬度带改正率稍差；BDGIM模型性能总体优于其他模型，全球范围改正率可达76.91%。

Accuracy evaluation of multi-GNSS broadcast ionospheric model

Ionospheric error is one of the main error sources for navigation and positioning, and broadcast ionospheric models provide a simple and effective method for single-frequency users to correct ionospheric delays. In this paper, the GIM product provided by CODE is used as the benchmark for evaluation, and the accuracy of four major broadcast ionospheric models is evaluated in various aspects, aiming to provide reference for subsequent model improvement and application. The results show that:the correction rate of each model is higher in the northern hemisphere than in the southern hemisphere, and the daytime correction rate is higher than that in the night. The NeQuick model has an average service performance in the middle and low latitudes, but is significantly higher than the BDSK8 and GPSK8 models in the high latitudes, and the correction rate is about 5% higher than that of the BDGIM model.The BDSK8/GPSK8/BDGIM model has the highest correction accuracy in the middle and low latitudes, and the correction in the high latitude band is The accuracy of BDSK8/GPSK8/BDGIM model is the highest in middle and low latitudes, and the correction rate of high latitude band is slightly worse. BDGIM model performs better than other models in general, and the global range correction rate can reach 76.91%.