Flock of Birds®

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The Flock can be configured to track from one to four sensors simultaneously with one or more RS-232 interfaces to a host computer. Long range coverage is easily added by "clicking in" our Extended-Range Transmitter (ERT/ERC). For high speed operations, add more RS-232 ports and use our Fast Bird Bus (FBB).

Click here to download the product brochure (PDF).

Three separate transmitter options are available for use with our Flock of Birds magnetic trackers. Whether you want to track motions at short, mid or long range, we have the right option for you.

Choices run from a small lightweight transmitter designed for precise, close-range usage to a powerful long-range transmitter pair, providing enough coverage for multiple performers to be tracked throughout a full-sized room.

The following chart will help you choose the right one for your applications.

Short-Range Transmitter
Mid-Range Transmitter
Extended-Range Transmitter
Up to +3 ft (0.9 m) coverage
Up to +4 ft (1.2 m) coverage
Up to +10 ft (3.0 m)

Set-up & Use:

This small, light-weight transmitter is often mounted on an articulated arm that can be brought close to its sensors. Especially useful for high accuracy medical applications.

Set-up & Use:

Our mid-range transmitter is ideal for desktop applications in environments containing conductive metals.

Set-up & Use:

One or two ERTs* can be operated in tandem to provide full coverage over 10 ft x 15 ft(3 m x 4.5 m) range of operation. Available with mounting stands.

*Requires customer software modifications to implement two ERTs.

  • Head/Hand/Instrument Body Tracking
    • Virtual reality
    • Flight simulation
    • Scientific visualization
    • Medical Imaging
    • Entertainment
  • Biomechanical/Human Factors Analysis
  • Rehabilitative Feedback & Assessment
  • 3D Graphics Control & Manipulation

Read how people are using Flock of Birds in real-world applications.

June 1, 2004: Ascension Flock Trackers Selected for F/A-22 Air Combat Simulation

December 1, 2003: Ascension Trackers Help Imaginations Bloom at Chicago's Children's Museum

August 26, 2003: Ascension and BARCO Deliver Immersive Visualization System to the University of Calgaray for New Engineering Research Center

August 7, 2002: Ascension Trackers Enhance Oil and Gas Recovery Visualization System

Pulsed DC magnetic technology
  • Five times less susceptible to distortion caused by nearby metal than AC technology.
Simultaneous Measurement of Multiple Sensors
  • No reduction of measurement rates.
Available in flexible configurations: mid-range or extended-range
  • Track up to 4 sensors at a range of up to 3.05 meters.
6 degrees-of-freedom
  • Unrestricted range of motion.

Translation range: Up to +1.2m (3.94 ft) in any direction with an option of 3.05m (10 ft)
Angular range: ±180° Azimuth & Roll ±90° Elevation
Static Accuracy Position*: 1.8mm RMS
Static Accuracy Orientation*: 0.5° RMS
Static Resolution Position: 0.5mm  @ 30.5cm
Static Resolution Orientation: 0.1° @ 30.5cm
Measurement rate: Up to 144 measurements/second
Outputs: X,Y,Z positional coordinates and orientation angles, rotation matrix, or quaternions
Interface: RS-232C with selectable baud rates to 115,200, USB converter is available.
Format: Binary
Modes: Point or stream
Transmitter: Mid-Range Transmitter: 9.6cm cube with 3.05M cable, or extended range transmitter option: 30.5cm cube with 6.1m cable
Sensor: 25.4mm x 25.4mm x 20.3mm cube (or optional 3-button mouse) with 3.05M or 10.7M cable. Weight: 21 g (0.7 oz) without cable, 169 g (6.0 oz) with 3.05M cable, 394 g (13.9 oz) with 10.7M cable.
Enclosure: 24cm x 29cm x 6.6cm
Power: User provided or optional external plug-in: US/European version
Environment: Metal objects and stray magnetic fields in the operation volume will degrade performance.

*Accuracy verified over range from 20.3cm to 76.2cm.

Flock of Birds is a general-purpose motion tracker suitable for many applications. Biomedical references in this document are examples of what medical companies have done with Ascension trackers after obtaining all necessary medical certifications. Ascension trackers are not certified for use in medicine without the end user/OEM complying with all pertinent FDA/CE regulatory requirements.

  • FCC Part 15, Class A
  • CE: EN 50081-1, Class A
    EN 50082-1, Class 2
    EN 61010-1

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Simulation & Training
Military - Helmet Tracking
Virtual Reality & Visualization
Medical & Medical Simulation
  Animation & Motion Capture

Click here to obtain pricing for this product, or call 
(802) 893-6657.

© 2005 Ascension Technology Corporation.  All Rights Reserved. P.O. Box 527 Burlington, VT 05402, USA.
For inquiries, call (802) 893-6657 or e-mail