TiMax TTd4 Tag

Combining technologies to achieve high accuracy location
Each TTd4 Tag transmits a continuous stream of very short low energy radio frequency data packetscontaining its ID.The packets are detected by the TTd4 Sensors which measure the Angle of Arrival at each sensor andthe Time Difference of Arrival between each pair of sensors.The Location Engine software is able to calculate the location of the tag by applying the measuredangles and times to a virtual geometric model of the space using the known sensor positions andcalibrated interconnection cable lengths.The unique combinations of tracking technologies allow a tag to be located accurately in 3D when seenby only two sensors, this compares favourably with TDoA only tracking systems where typically 5sensors must see a tag for a 3D location and yields much more robust tracking than AoA only basedtechnologies which are highly susceptible to errors due to multi‑path reflections.

Location using Angle of Arrival (AoA)
Sensors are equipped with an internal multipleantenna array that allows each sensor tomeasure the angle on incidence of the radiofrequency pulse transmitted by the tag.The software contains a geometric model of thespace and so from the reported angles of arrivalat the sensors, the software can determine theposition of the tag.

Location using Time Difference ofArrival (TDoA)
All the sensors are synchronised to a highlyaccurate clock signal allowing the software tomeasure the Time Diference of Arrivalbetween each pair of sensors of the radiofrequency pulse transmitted by the tag.The software contains a geometric model ofthe space and from the reported timedifferences can determine the position of thetag by working out where the TDoA curvesintersect.

Considerations for best performance
At least 2 sensors must see the tag to make a location and if more sensors see the tag from differentpoints of view the accuracy will be enhanced further.Ensure that the area to be tracked is covered by sensors from the front, behind and at the sides, it isvery important that the tag is seen from as many points of view as possible for accurate location.The RF pulse transmitted by the tag is very high frequency and low energy and will not pass through ahuman body.Ensure the tag is worn by the performer in a position to ensure best all round visibility to the sensorsfrom all points of view. Best tag positions are in hats and wigs. Tags mounted at the nape of the neck orin‑between shoulder blades are also a good positions. The usual position is in a pouch on the radio belt.Try to find places where the tag is most visible from the widest possible angle and minimally shadowedby the wearers anatomy, i.e. arms and spare tyres.Costume material can also have an effect on tracking performance ‑ metallic thread and sequins canhave a detrimental effect.Study set construction and materials and choose sensor locations to minimise possible multipathreflections caused by metallic or foil surfaces that may reflect radio frequency signals.

TTd4 Tags are supplied factory programmed with their update rate and while active willcontinue to transmit location pulses. Tags are activated and de‑activated using amagnet. Tags will run for several months (depends on update rate) and indicate lowbattery status when the battery is discharged by around 90%.

TTd4 Tag Specifications
Dimensions: 54mm x 40mm x 14mm (2.1" x 1.6" x 0.6")
Weight: 28g (1.0 oz.)Temperature: ‑40°C to 85°C (‑40°F to 185°F)
Humidity: 0 to 95%, non‑condensing
Enclosure: UV‑stabilised polycarbonate enclosure, silicone gasket V‑0 flammability‑rated Ingress protection to IP67and IP69KUpdate rate: Standard 10/20/50Hz, other custom frequencies are available
Peripherals: Activity feedback LED Magnetic reed switch (operable through enclosure) Motion detector
Radio frequencies: Ultra‑wideband channel: 6 ‑ 7GHz Telemetry channel (optional): Narrow‑band 2.4GHz
Certifications: US: FCC Part 15 FCC ID SEAMOD31
EU: CE
Canada: RSS‑Gen, RSS‑102, RSS‑210, RSS‑220 Industry Canada ID 8673A‑MOD31
Power supply: Replaceable lithium thionyl chloride battery (LTC‑7PN)
Reliability: Estimated Mean‑Time‑Before‑Failure (MTBF): 25 years