About Electromagnetics

Polhemus AC (alternating current) electromagnetic field that will track anything in its range
          The Polhemus source emits an AC electromagnetic field that will track anything in its range.

6DOF: Reliable Data, Repeatable Results

Polhemus is known for its award-winning, proprietary technology, AC (alternating current) electromagnetics. Our technology is able to track a wide variety of objects, as well as people, by attaching small and lightweight sensors to selected tracking points or embedding them within an object. Polhemus trackers deliver true 6DOF (Degrees-Of-Freedom) because both position and orientation are measured automatically and natively to the tracking technology such that no hybrid data merging is needed to obtain the full position and orientation solution. The person or object's position is tracked within X, Y and Z coordinates of a space, as well as the object's orientation, otherwise known as yaw, pitch and roll.


There are several advantages to using Polhemus electromagnetic technology:  Our AC electromagnetics typically deliver longer range tracking than some competing technologies, and operate at lower power levels. Additionally, it offers the best signal-to-noise ratios and is unique in that multiple tracking systems can be used in the same environment, without any cross-talk interference. Perhaps the main benefit of AC electromagnetics is the unmatched precision it delivers, with reliable and repeatable tracking results.

How It Works

Sometimes when we demonstrate our motion tracking technology, those not familiar with electromagnetics ask, “How is it tracking?” Our answer -- It’s not magic—it’s the power of tuned electromagnetic fields and years of proprietary development. Polhemus motion tracking systems utilize a source (think of it as a magnetic transmitter) which emits an electromagnetic dipole field, as pictured above. The size of the field varies, depending on the size of the source used; the larger the magnetic field the larger the tracking range (coverage area).  Most Polhemus systems are scalable so you can increase your tracking area simply by adding additional tracker components.

Embeddable Components & Flexible Set Up

Polhemus electromagnetics has attributes that set it apart from all other tracking technology. For starters, did you know our motion tracking sensors can be embedded inside many materials? Even when the sensors are completely covered, they still track position and orientation seamlessly. This means you can embed Polhemus sensors inside your custom form factor, making it the top choice for many training and simulation applications. The source, or transmitter, can also be embedded or covered and tracking accuracy is fully maintained.

The source can also be mounted on a tripod, buried in a potted plant, or embedded inside your product. Polhemus tracking systems have a lot of flexibility in terms of set up, so you are able to tailor the setting to meet your application needs or even when your environment changes  --  Polhemus systems are very portable. Mount the source on the ceiling for one application, set it up on a tripod, or bury the source underground for a different application. With flexibility in the set up, you are in control of adapting the tracking technology to your environment.

No Line-of-Sight--No Problem. And No Drift.

Because no cameras are used with Polhemus technology, a line-of-sight is not necessary for continuous tracking. With cameras, the points being tracked cannot be out of view. With Polhemus electromagnetics, there are no cameras to align, no special lighting required, and you don’t need to be in a field of view. Polhemus technology has the ability to track through people and most walls. Drift (error in tracking output over time) is never an issue, as with inertial technologies because Polhemus technology is solid-state. There are no MEMS, Gyros, Accelerometers or Magnetometers involved so there is never a need to correct data due to drift over time.

Polhemus is the genesis of all magnetic tracking.  Our proprietary technology is specialized and focused on innovative and affordable tracking solutions that enable our customers to break new ground within their fields of expertise.  Our technology powers applications in a wide variety of markets, catering to health care, military, and in countless research areas. Read about how our technology is being used in Case Studies.

For more information, contact: sales@polhemus.com.