Enhancing GNSS receiver performance with software-defined vector carrier tracking for rocket launching
M.A. Gómez, Alberto Solera-Rico, Eusebio Valero, Javier Arribas Lázaro, Carles Fernández–Prades
Abstract
It is well-known that the use of Vector Tracking Loops (VTL) in GNSS receivers can result in improved tracking performance and sensitivity, faster acquisition, and improved interference robustness. However, despite the availability of software-defined radio (SDR) GNSS receivers in practical applications, there is currently no open-source implementation of Vector Tracking techniques able to operate in real-time. This work introduces a VTL algorithm applied to track the Doppler shift and its rate, using the open-source GNSS-SDR framework. This leads to a novel real-time SDR GNSS VTL receiver capable to work with different COTS front-ends. The proposed implementation was tested in a challenging non-conventional, high dynamics positioning scenario to obtain the position and velocity vectors of a rotation-stabilized guided rocket. The scenario was simulated with a GNSS RF signal generator, captured with a COTS front-end and processed by GNSS-SDR. Results show that the algorithm and its proposed implementation are able to provide full tracking, even under demanding accelerations. The positioning performance is measured using standard metrics, and we provide a fully automated reproducibility path. The source code is released under the General Public License v3.0, and will contribute to GNSS-SDR's open-source code base.