WaviTrack Dataset

Dataset summary

Dataset	Participants	Sequences	Duration
Main Dataset (p01–p15)	15	46	Approximately 3.04 hours
Supplementary IMU-only Dataset (p91–p97)	7	14	Approximately 1.52 hours

The supplementary dataset is provided for IMU-only use because its UWB availability is very poor, while its IMU measurements remain usable.

Data structure

Each sequence contains a sensor NPZ file, a SMPL-X motion NPZ file and a calibration JSON file. Calibration files accompany the sensor data. The two collections use the same structure.

Matching pXX_sYY identifiers associate the three files; pXX identifies the participant and sYY the sequence, each with two digits. For example: p01_s01_sensors.npz, p01_s01_smplx_stageii.npz and p01_s01_calibration.json.

Sensor node order is Head, Left_Wrist, Right_Wrist, Left_Knee, Right_Knee, Hip, as recorded in sensor_order. T denotes sensor samples.

Sensor NPZ: key fields

Field	Shape	Description
accel, gyro	[T,6,3]	Sensor-local acceleration and angular velocity
quat	[T,6,4]	Sensor-to-IMU-world orientation quaternion
ranging	[T,15]	Measured UWB distances
cir	[T,15,96]	Real-valued CIR amplitudes, 96 taps per link; not complex I/Q
cir_valid	[T,15]	Observed CIR validity mask
accel_world_input, gyro_world_input	[T,6,3]	Prepared world-vector inputs for the calibration formulas below
quat_world_input	[T,6,4]	Prepared orientation input for calibration
time_seconds	[T]	Sequence-relative timestamps
sensor_order, pair_nodes	[6], [15,2]	Node names and zero-based node-pair mapping for the UWB/CIR arrays

Calibration JSON and metadata

The calibration JSON contains sequence_id, sensor_order, quaternion_order and per-node 3×3 matrices at sensors[<node name>]["L"] and sensors[<node name>]["B"].

Each collection also includes dataset_metadata.json, describing the dataset, participant and sequence identifiers, sequence durations and data fields.

Units and sampling rates

Acceleration is in m/s²; the measured local accel field includes gravity. Angular velocity is in rad/s, distances and translations in metres, and timestamps in seconds. Sensors are sampled at a nominal 60 Hz and SMPL-X motion at 120 Hz.

Motion processing

Motion-capture C3D recordings are converted to SMPL-X motion parameters using our Torch OptiTrack to AMASS converter.

Use the SMPL-X Python library with the SMPL-X model. Model files can be obtained from the official SMPL-X website under their separate licence.

Coordinate conventions and calibration

Sensor quaternions use xyzw ordering; SMPL-X rotations use axis-angle vectors in radians. The calibration matrices act on column vectors: L maps prepared world-frame inputs to the motion coordinate frame, while B corrects the orientation's mounting/frame convention.

Use the calibration file with the same sequence identifier, and apply each node's own matrices:

R_cal   = L @ Rotation(quat_world_input) @ B
acc_cal = L @ accel_world_input
gyro_cal = L @ gyro_world_input

Here, Rotation(q) denotes the 3×3 rotation matrix represented by quaternion q. Apply B only to orientation, not acceleration or angular velocity. The prepared world-vector inputs already include the required offsets; do not repeat their world conversion or subtract those offsets again.

Data quality

The SMPL-X motion is a fitted estimate rather than error-free ground truth. Sensor quality and UWB/CIR availability can vary; the supplementary collection is intended for IMU-only use, not UWB/CIR training or evaluation. CIR validity indicates an available observation, not a guarantee of ranging accuracy.

Visualisation tools

Motion and sensor visualisation tools will be published in WaviTrack-RF-Motion/simulation/tools. Usage details will be provided in that repository.

Licence and participant protection

Use is restricted to your approved non-commercial academic research or educational purpose. Commercial or industrial use—including analysis, model training, evaluation and product development—is prohibited.

Do not redistribute the dataset or record-level derived data, share accounts or credentials, or attempt to identify, re-identify or contact participants. Necessary secure working and backup copies for approved use are governed by the licence.

Read LICENSE.txt, USER_AGREEMENT.txt and the full licence and access agreement for all conditions, including publication requirements. This summary does not replace them.

Acknowledgements and contact

We thank all volunteers who participated in data collection and everyone who supported the collection process.

For dataset questions, permission enquiries or privacy requests, contact admin@wavitrack.com.