Closed-Loop Estimation of Oscillator g-Sensitivity in a GNSS/IMU System

TL;DR

This paper introduces a straightforward, equipment-free method for estimating oscillator g-sensitivity in GNSS/IMU systems by analyzing phase tracking errors, enabling calibration without specialized tools.

Contribution

It presents a novel closed-loop approach that uses GNSS signals as a frequency reference to estimate g-sensitivity without additional hardware.

Findings

Successfully applied to calibrate oven-controlled crystal oscillator

Effective in estimating g-sensitivity using existing GNSS signals

Does not require specialized equipment like simulators or rate tables

Abstract

We propose a simple method for estimating crystal oscillator g-sensitivity in inertially aided Global Navigation Satellite System (GNSS) receivers. It does not require any specific equipment, like GNSS signal simulators or rate tables. The method is based on analyzing closed-loop phase tracking errors. This enables us to utilize the actual GNSS signal as the frequency reference, despite the presence of an unknown Doppler shift in it. The method has been successfully applied to the calibration of an oven-controlled crystal oscillator.