Magnetometer-enhanced personal locator for tunnels and GPS-denied outdoor environments

Surat Kwanmuang; Lauro Ojeda; Johann Borenstein

doi:10.1117/12.885346

2 June 2011 Magnetometer-enhanced personal locator for tunnels and GPS-denied outdoor environments

Surat Kwanmuang, Lauro Ojeda, Johann Borenstein

Proceedings Volume 8019, Sensors, and Command, Control, Communications, and Intelligence (C3I) Technologies for Homeland Security and Homeland Defense X; 80190O (2011) https://doi.org/10.1117/12.885346
Event: SPIE Defense, Security, and Sensing, 2011, Orlando, Florida, United States

Abstract

This paper describes recent advances with our earlier developed Personal Dead-reckoning (PDR) system for GPS-denied environments. The PDR system uses a foot-mounted Inertial Measurement Unit (IMU) that also houses a three axismagnetometer. In earlier work we developed methods for correcting the drift errors in the accelerometers, thereby allowing very accurate measurements of distance traveled. In addition, we developed a powerful heuristic method for correcting heading errors caused by gyro drift. The heuristics exploit the rectilinear features found in almost all manmade structures and therefore limit this technology to indoor use only. Most recently we integrated a three-axis magnetometer with the IMU, using a Kalman Filter. While it is well known that the ubiquitous magnetic disturbances found in most modern buildings render magnetometers almost completely useless indoors, these sensors are nonetheless very effective in pristine outdoor environments as well as in some tunnels and caves. The present paper describes the integrated magnetometer/IMU system and presents detailed experimental results. Specifically, the paper reports results of an objective test conducted by Firefighters of California's CAL-FIRE. In this particular test, two firefighters in full operational gear and one civilian hiked up a two-mile long mountain trail over rocky, sometimes steeply inclined terrain, each wearing one of our magnetometer-enhanced PDR systems but not using any GPS. During the hour-long hike the average position error was about 20 meters and the maximum error was less than 45 meters, which is about 1.4% of distance traveled for all three PDR systems.

Citation Download Citation

Surat Kwanmuang, Lauro Ojeda, and Johann Borenstein "Magnetometer-enhanced personal locator for tunnels and GPS-denied outdoor environments", Proc. SPIE 8019, Sensors, and Command, Control, Communications, and Intelligence (C3I) Technologies for Homeland Security and Homeland Defense X, 80190O (2 June 2011); https://doi.org/10.1117/12.885346

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available