Motion Capture Data Export Format

Some active tasks capture detailed motion data. For example, the fitness check, short walk, and range of motion tasks can record details about the device motion and acceleration during the test.

Data File Organization

Motion capture data is stored separately from other exported data. There are separate motion capture files for each survey step that recorded motion data. These files are stored within the "SurveyData" folder using the following path:

SurveyData/{ParticipantIdentifier}/{SurveyResultKey}/{StepIdentifier}/{DataFile}

For example:

SurveyData/264b2a09-3ff0-4668-8a0a-bd0ee59bf9584/24be41e0-a2e2-40ce-871e-9ffa7e685926/GAIT_TEST/Accelerometer.json

The ParticipantIdentifier, SurveyResultKey, and StepIdentifier all correspond to the values in the Survey Step Results export file.

Data file names are shown in the table below:

Accelerometer Data

Accelerometer data captures device motion at a set frequency (100Hz by default).

{
  "items": [
    {
      "y": -0.440582275390625,
      "timestamp": 867.9697944999999,
      "z": -0.888946533203125,
      "x": 0.0896148681640625
    },
    {
      "y": -0.4400634765625,
      "timestamp": 867.9797424999999,
      "z": -0.8815765380859374,
      "x": 0.0867767333984375
    },
    ...
}

Pedometer Data

Pedometer data captures a summary of the participant's movement, as reported by the device.

{
  "items": [
    {
      "floorsAscended": 0,
      "floorsDescended": 0,
      "endDate": "2021-01-20T11:12:39-0600",
      "startDate": "2021-01-20T11:12:32-0600",
      "numberOfSteps": 9,
      "distance": 3.9248944195569493
    },
    {
      "floorsAscended": 0,
      "floorsDescended": 0,
      "endDate": "2021-01-20T11:12:42-0600",
      "startDate": "2021-01-20T11:12:32-0600",
      "numberOfSteps": 13,
      "distance": 5.865757531253621
    },
    ...
  ]}

Device Motion Data

This data file captures general device orientation and motion at a set frequency (100Hz by default).

{
  "items": [
    {
      "attitude": {
        "y": 0.04419703935756934,
        "w": 0.9729538185300793,
        "z": 0,
        "x": 0.22673223719225216
      },
      "timestamp": 867.9772564999998,
      "rotationRate": {
        "x": -0.04906965792179108,
        "y": 0.005430211313068866,
        "z": 0.0395255722105503
      },
      "userAcceleration": {
        "x": 0.002985894680023193,
        "y": 0.0006634891033172609,
        "z": 0.006300091743469239
      },
      "gravity": {
        "x": 0.08600335568189622,
        "y": -0.4411999881267547,
        "z": -0.8932782411575315
      },
      "magneticField": {
        "y": 0,
        "z": 0,
        "x": 0,
        "accuracy": -1
      }
    },
    {
      "attitude": {
        "y": 0.04417244199634487,
        "w": 0.9730006423304092,
        ...
    },
    ...
  ]}