# Eliminate Dynamic Error of A-PNAS High-Precision Time Synchronization Using Multi-Sensor Combination

## TL;DR

This paper proposes a multi-sensor method to correct dynamic errors in high-precision time synchronization for airborne navigation systems.

## Contribution

A novel multi-sensor combination method is introduced to correct dynamic errors in A-PNAS time synchronization.

## Key findings

- Dynamic errors in time synchronization can be reduced by approximately 80% using the proposed method.
- The method meets the requirement for meter-level positioning accuracy with 2 ns time synchronization.
- The approach is applicable to similar space-based platform systems requiring high-precision synchronization.

## Abstract

High-precision time synchronization among nodes of the airborne-based pseudolite navigation augmentation positioning system (A-PNAS) is a crucial indicator for ensuring the accuracy of positioning services. Due to the flight characteristics and external factors’ influence, the airborne platform usually undergoes random motion. Therefore, the time-varying effect errors and Doppler effect errors will be introduced into the clock skew measurement results during the time-synchronous processing. In A-PNAS with meter-level positioning accuracy, the time synchronization accuracy (TSA) between nodes usually needs to be within 2 ns. These dynamic errors will have an impact on the TSA between nodes, which cannot be ignored. Based on the analysis of the principle of dynamic error generation and the available sensors, a multi-sensor combination method for correcting dynamic errors is proposed. This method calculates and corrects the dynamic errors based on the motion measurements from sensors. The simulation test results show that the degree of improvement in correcting dynamic errors by this method is basically close to 80%. It can effectively meet the requirements of high-precision time synchronization system and can provide an effective reference for the high-precision time synchronization processing of similar space-based platform collaborative systems.