{
  "id": 582475,
  "title": "Sampling Rate",
  "url": "/competitions/cmi-detect-behavior-with-sensor-data/discussion/582475",
  "author_name": "Diego Silva França",
  "post_date": "2025-05-31T14:26:44.523000",
  "votes": 22,
  "comment_count": 6,
  "views": 0,
  "content": "<p>What is the sampling rate of the sensors? especially the IMU sensors?</p>",
  "messages": [
    {
      "id": 3214435,
      "postDate": "2025-05-31T14:26:44.523Z",
      "content": "<p>What is the sampling rate of the sensors? especially the IMU sensors?</p>",
      "rawMarkdown": "What is the sampling rate of the sensors? especially the IMU sensors?",
      "votes": 22
    },
    {
      "id": 3216756,
      "postDate": "2025-06-04T04:33:00.730Z",
      "content": "<p>It says \"1 kHz\" in the documents:</p>\n<p><a href=\"https://fcon_1000.projects.nitrc.org/indi/cmi_healthy_brain_network/Competitions/Helios2025/IMU_Sensor.pdf\" target=\"_blank\">https://fcon_1000.projects.nitrc.org/indi/cmi_healthy_brain_network/Competitions/Helios2025/IMU_Sensor.pdf</a></p>",
      "rawMarkdown": "It says \"1 kHz\" in the documents:\n\nhttps://fcon_1000.projects.nitrc.org/indi/cmi_healthy_brain_network/Competitions/Helios2025/IMU_Sensor.pdf",
      "votes": 2,
      "replies": [
        {
          "id": 3216838,
          "postDate": "2025-06-04T06:39:37.807Z",
          "content": "<p>Yes but that's the sampling rate of the sensor. With sequences of 50 rows, it would mean that only 0.05s of movement is recorded. So the measured values are probably averaged over a bigger time range. (0.1s or so?)</p>",
          "rawMarkdown": "Yes but that's the sampling rate of the sensor. With sequences of 50 rows, it would mean that only 0.05s of movement is recorded. So the measured values are probably averaged over a bigger time range. (0.1s or so?)",
          "votes": 4,
          "replies": [
            {
              "id": 3218088,
              "postDate": "2025-06-05T19:27:49.830Z",
              "content": "<p>The videos of the gestures are about 5-6 seconds each, which would imply about 10 Hz sample frequency?</p>",
              "rawMarkdown": "The videos of the gestures are about 5-6 seconds each, which would imply about 10 Hz sample frequency?",
              "votes": 4
            },
            {
              "id": 3219595,
              "postDate": "2025-06-08T03:03:30.823Z",
              "rawMarkdown": "",
              "isDeleted": true
            },
            {
              "id": 3219596,
              "postDate": "2025-06-08T03:03:56.073Z",
              "content": "<p>That sounds like a reasonable speculation! Perhaps the organizers downsampled the data by a factor of 100?</p>",
              "rawMarkdown": "That sounds like a reasonable speculation! Perhaps the organizers downsampled the data by a factor of 100?",
              "votes": 1
            },
            {
              "id": 3228728,
              "postDate": "2025-06-20T12:59:25.213Z",
              "content": "<p>Probably they downsampled it and applied some kind of anti-aliasing technique</p>",
              "rawMarkdown": "Probably they downsampled it and applied some kind of anti-aliasing technique"
            }
          ]
        }
      ]
    }
  ],
  "comments": [
    {
      "id": 3216756,
      "author_name": "Mert Bayraktar",
      "author_url": "",
      "post_date": "2025-06-04T04:33:00.730000",
      "content": "<p>It says \"1 kHz\" in the documents:</p>\n<p><a href=\"https://fcon_1000.projects.nitrc.org/indi/cmi_healthy_brain_network/Competitions/Helios2025/IMU_Sensor.pdf\" target=\"_blank\">https://fcon_1000.projects.nitrc.org/indi/cmi_healthy_brain_network/Competitions/Helios2025/IMU_Sensor.pdf</a></p>",
      "votes": 2,
      "replies": [
        {
          "id": 3216838,
          "author_name": "TomVdB",
          "author_url": "",
          "post_date": "2025-06-04T06:39:37.807000",
          "content": "<p>Yes but that's the sampling rate of the sensor. With sequences of 50 rows, it would mean that only 0.05s of movement is recorded. So the measured values are probably averaged over a bigger time range. (0.1s or so?)</p>",
          "votes": 4,
          "replies": [
            {
              "id": 3218088,
              "author_name": "Graham Jones",
              "author_url": "",
              "post_date": "2025-06-05T19:27:49.830000",
              "content": "<p>The videos of the gestures are about 5-6 seconds each, which would imply about 10 Hz sample frequency?</p>",
              "votes": 4,
              "replies": []
            },
            {
              "id": 3219595,
              "author_name": "",
              "author_url": "",
              "post_date": "2025-06-08T03:03:30.823000",
              "content": "",
              "votes": 0,
              "replies": []
            },
            {
              "id": 3219596,
              "author_name": "Jack Lee",
              "author_url": "",
              "post_date": "2025-06-08T03:03:56.073000",
              "content": "<p>That sounds like a reasonable speculation! Perhaps the organizers downsampled the data by a factor of 100?</p>",
              "votes": 1,
              "replies": []
            },
            {
              "id": 3228728,
              "author_name": "Diego Silva França",
              "author_url": "",
              "post_date": "2025-06-20T12:59:25.213000",
              "content": "<p>Probably they downsampled it and applied some kind of anti-aliasing technique</p>",
              "votes": 0,
              "replies": []
            }
          ]
        }
      ]
    }
  ],
  "raw_markdown_by_id": {
    "3214435": "What is the sampling rate of the sensors? especially the IMU sensors?",
    "3216756": "It says \"1 kHz\" in the documents:\n\nhttps://fcon_1000.projects.nitrc.org/indi/cmi_healthy_brain_network/Competitions/Helios2025/IMU_Sensor.pdf"
  }
}