Analysis of Observation Error Characteristics in the Presence of Differential Ages

Because 4G radio stations, wireless radio stations, and data links are vulnerable to electromagnetic interference, path occlusion, and network delay during data transmission. This makes the differential of age (DOA) often occur when obtaining the differential information of the reference station. This study establishes theoretical models for various observation domain errors in the presence of differential ages. It analyzes the characteristics of satellite geometric changes and ionospheric delay errors under different differential ages. This provides a reference for improving the positioning performance of asynchronous RTK. Three pairs of baselines worldwide were selected for the experiment to extract various errors during the active period of the ionosphere. The results show that even when the DOA is 180 seconds, the change of the geometric term is within 0.04. When the DOA is relatively large, the inter-station difference of ionospheric delay error can reach several decimeters or even the meter level, especially during the ionospheric active period. This indicates that the geometric terms have a negligible influence on the RTK positioning algorithm. The ionospheric delay error is one of the most intractable problems affecting asynchronous RTK.