Global tropospheric delay grid modeling based on Anti-Leakage Least-Squares Spectral Analysis and its validation

Tropospheric delay is one of the primary error sources Global Navigation Satellite System (GNSS). Usually, a traditional empirical model can be corrected, which uses trigonometric function fixed amplitude and frequency for time fitting. However, models only retain low-frequency information zenith tropospheric (ZTD), limits its application in high resolution. To solve this problem, global grid model, namely AGtrop, developed based on Anti-Leakage Least-Squares Spectral analysis. The results AGtrop are evaluated by three kinds sources, including ERA5 data, IGS, sounding profile radiosonde station throughout year 2019. Compared with GPT2w UNB3m, shows better performance, especially low latitudes southern hemisphere. generally achieve mean Bias/RMSE 0.35/2.34 cm contrast to derived ZTD, 0.59/2.29 comparison IGS 0.18/3.71 match Radiosonde ZTD. Besides, has an enhancement effect localized areas. characterized simplicity accuracy, will great significance real-time GNSS applications.