Low Frequency Radio Polarization Sensor with Applications in Attitude Estimation

Change log
Maguire, STG 
Robertson, PA 

A novel method of attitude (orientation) estimation is proposed, which makes use of measurements of the polarization of the magnetic (H-) field of Low Frequency (LF) radio signals. This offers advantages relative to existing accelerometer-based systems in high-acceleration, cost-constrained environments such as small fixed-wing Unmanned Aerial Vehicles. In order to validate this method, a sensor system is presented which is capable of determining the H-field polarization of LF radio signals from three-axis measurements. The sensor system consists of an array of three orthogonal loop antennas, a three channel radio receiver circuit, a datalogging and control module and data processing algorithms. This system is shown to accurately measure the axis of H-field polarization for signals with linear or almost linear polarization, subject to a sign ambiguity. A representative AM radio broadcast in the LF band is shown to have a substantially linear polarization, measurements of which are used to determine a receiver’s heading angle. The stability of these polarization measurements over time, and the distorting effect of certain structures, are quantified. The feasibility of this method of attitude determination is therefore demonstrated.

Antenna arrays, attitude, low frequency, magnetic sensors, polarization, UAV
Journal Title
IEEE Sensors Journal
Conference Name
Journal ISSN
Volume Title
Institute of Electrical and Electronics Engineers (IEEE)