An Advanced Standalone GNSS Navigation Architecture for High-Dynamic Applications via Carrier Phase TDDD with Rapid Hotstart Capability

Abstract

This research addresses the challenges of accuracy and reliability in Standalone Global Navigation Satellite System (GNSS) receivers under high dynamic (HD) applications, where signal loss-of-lock is frequent. An advanced architectural design is proposed, utilizing carrier phase measurements and the Time-Differenced Double Difference (TDDD) method. To ensure robust tracking, a 5-state Kalman Filter (KF)-based tracking loop replaces the traditional Phase-Locked Loop (PLL), optimizing phase, frequency, and frequency derivative to enhance sensitivity. The reliable phase data is processed by a 9-state TDDD Positioning KF (PKF), which features an extended model for estimating high-order acceleration components. Measurement quality is maintained using the Normalized Innovation Squared (NIS) test to effectively eliminate cycle slips. The Sequential Kalman Filter (SKF) is employed to simplify implementation and ensure realtime capability. Significantly, the architecture incorporates a rapid hotstart mechanism to minimize the Time To First Fix (TTFF), ensuring the agility required for HD maneuvers. The entire proposed architecture was successfully implemented and validated on the Field-Programmable Gate Array (FPGA) Zynq-7000 platform, confirming its efficiency and suitability for realtime HD GNSS processing. The model significantly improves positioning performance compared to traditional methods, providing a robust solution for independent GNSS navigation.