Characterization of Lightweight GPS Disciplined Oscillators for Distributed UAV Measurement Applications

TL;DR

This paper evaluates lightweight GNSS disciplined oscillators for UAVs, analyzing their stability and performance under flight conditions and signal impairments to ensure precise synchronization in dynamic environments.

Contribution

It introduces a measurement system using SDRs to characterize GNSSDOs for UAV flight, considering real-world vibrations and signal impairments, which was previously overlooked.

Findings

GNSSDOs maintain stability under certain impairments

Flight vibrations impact oscillator performance

Measurement system predicts in-flight measurement precision

Abstract

With an increasing variety of measurement applications using sensing nodes on unmanned aerial vehicles (UAVs), global positioning system (GPS) and global navigation satellite system (GNSS) disciplined oscillators (GPSDOs, GNSSDOs) are an appealing solution for precise wireless inter-device synchronization. Typically evaluated under laboratory conditions by analyzing the 10 MHz and 1 pulse per second (PPS) reference signal stability, these test methods overlook airborne oscillator performance. This paper characterizes lightweight GNSSDO models for flight suitability using a measurement system based on software defined radios (SDRs). We analyze reference signal stability under controlled GNSS signal impairments to predict performance and measurement precision loss in dynamic operational modes. Additionally, we assess behavior under the impacts caused by operating the UAV, as well as typical flight vibrations and accelerations outlined in the standard for payload devices.