{
  "id": 263995,
  "title": "What's up with 306Hz?",
  "url": "/competitions/g2net-gravitational-wave-detection/discussion/263995",
  "author_name": "",
  "post_date": "2021-08-10T18:33:33.803780600Z",
  "votes": 13,
  "comment_count": 6,
  "views": 0,
  "content": "<p>After cleaning the signal with bandpass (30Hz, 500Hz) and notch filters (60Hz and harmonics), I noticed that the US detectors (signal 1 &amp; 2) have spike around 306Hz regardless of the target with it being more prominent when target = 1</p>\n<p>ID: ffff9a5645<br>\n<a href=\"https://ibb.co/rHCvjfN\" target=\"_blank\">https://ibb.co/rHCvjfN</a></p>\n<p>I'm wondering if anyone else had the same observation and was able to decode/understand more information on this.</p>",
  "messages": [
    {
      "id": "1464856",
      "postDate": "08/10/2021 18:33:33",
      "content": "<p>After cleaning the signal with bandpass (30Hz, 500Hz) and notch filters (60Hz and harmonics), I noticed that the US detectors (signal 1 &amp; 2) have spike around 306Hz regardless of the target with it being more prominent when target = 1</p>\n<p>ID: ffff9a5645<br>\n<a href=\"https://ibb.co/rHCvjfN\" target=\"_blank\">https://ibb.co/rHCvjfN</a></p>\n<p>I'm wondering if anyone else had the same observation and was able to decode/understand more information on this.</p>",
      "rawMarkdown": "After cleaning the signal with bandpass (30Hz, 500Hz) and notch filters (60Hz and harmonics), I noticed that the US detectors (signal 1 & 2) have spike around 306Hz regardless of the target with it being more prominent when target = 1\n\nID: ffff9a5645\nhttps://ibb.co/rHCvjfN\n\nI'm wondering if anyone else had the same observation and was able to decode/understand more information on this.",
      "votes": null
    },
    {
      "id": "1468678",
      "postDate": "08/12/2021 14:26:36",
      "content": "<p>If it is more prominent when target=1, I wonder if it is a subtle leak?</p>\n<p>Does removing it using a notch filter reduce AUC?</p>",
      "rawMarkdown": "If it is more prominent when target=1, I wonder if it is a subtle leak?\n\nDoes removing it using a notch filter reduce AUC?",
      "votes": null
    },
    {
      "id": "1468875",
      "postDate": "08/12/2021 15:57:17",
      "content": "<p>I noticed it across 20ish randomly picked IDs.<br>\nI did try using notch filters, but my current LB on tiny networks swing between 0.84~0.85. I couldn't make a definite call on the impact it brings.</p>",
      "rawMarkdown": "I noticed it across 20ish randomly picked IDs.\nI did try using notch filters, but my current LB on tiny networks swing between 0.84~0.85. I couldn't make a definite call on the impact it brings.",
      "votes": null
    },
    {
      "id": "1468895",
      "postDate": "08/12/2021 16:08:01",
      "content": "<p>I did a crude check searching for a spike between 250-350Hz. If the max value is in the 305-307Hz range, I flagged it as True:</p>\n<table>\n<thead>\n<tr>\n<th></th>\n<th>Ch1 Spike</th>\n<th>Ch2 Spike</th>\n<th>Both Spikes</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>True</td>\n<td>525800</td>\n<td>525867</td>\n<td>493779</td>\n</tr>\n<tr>\n<td>False</td>\n<td>34200</td>\n<td>34133</td>\n<td>66221</td>\n</tr>\n</tbody>\n</table>\n<p>Looks like these spikes are very common and probably unrelated to the target. </p>\n<p>It would be interesting to understand what causes them though. There might be some harmonics floating around too.</p>",
      "rawMarkdown": "I did a crude check searching for a spike between 250-350Hz. If the max value is in the 305-307Hz range, I flagged it as True:\n\n| | Ch1 Spike | Ch2 Spike | Both Spikes |\n| ---- | --- | --- | --- |\n| True | 525800 | 525867 | 493779 | \n| False | 34200 | 34133 | 66221 |\n\nLooks like these spikes are very common and probably unrelated to the target. \n\nIt would be interesting to understand what causes them though. There might be some harmonics floating around too.",
      "votes": null
    },
    {
      "id": "1469042",
      "postDate": "08/12/2021 17:29:47",
      "content": "<p>Thanks, this is helpful</p>",
      "rawMarkdown": "Thanks, this is helpful",
      "votes": null
    },
    {
      "id": "1469115",
      "postDate": "08/12/2021 18:01:15",
      "content": "<p>On page 10 they mention a loud 300Hz signal, that on first read appears to be part of a dampening system. (Search: \"300 Hz\")<br>\n<a href=\"https://dcc.ligo.org/public/0122/P1500260/015/errata_authors_Martynov_PRD_AF.pdf\" target=\"_blank\">https://dcc.ligo.org/public/0122/P1500260/015/errata_authors_Martynov_PRD_AF.pdf</a></p>",
      "rawMarkdown": "On page 10 they mention a loud 300Hz signal, that on first read appears to be part of a dampening system. (Search: \"300 Hz\")\nhttps://dcc.ligo.org/public/0122/P1500260/015/errata_authors_Martynov_PRD_AF.pdf",
      "votes": null
    },
    {
      "id": "1561210",
      "postDate": "10/27/2021 12:20:02",
      "content": "<p>Hey All,</p>\n<p>Thank you all for taking part in our competition. The participation has been overwhelmingly positive. We are currently conducting a survey to gauge the demographic and outreach achieved. Kindly spare 2min and fill in this survey <a href=\"https://forms.gle/QP9L16niPexozyhu5\" target=\"_blank\">https://forms.gle/QP9L16niPexozyhu5</a>.</p>\n<p>Thank you all,</p>\n<p>Regards,<br>\nChris</p>",
      "rawMarkdown": "Hey All,\n\nThank you all for taking part in our competition. The participation has been overwhelmingly positive. We are currently conducting a survey to gauge the demographic and outreach achieved. Kindly spare 2min and fill in this survey https://forms.gle/QP9L16niPexozyhu5.\n\nThank you all,\n\nRegards,\nChris",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 1468678,
      "author_name": "anjum48",
      "author_url": "",
      "post_date": "08/12/2021 14:26:36",
      "content": "<p>If it is more prominent when target=1, I wonder if it is a subtle leak?</p>\n<p>Does removing it using a notch filter reduce AUC?</p>",
      "votes": null,
      "replies": [
        {
          "id": 1468875,
          "author_name": "harshpatel1692",
          "author_url": "",
          "post_date": "08/12/2021 15:57:17",
          "content": "<p>I noticed it across 20ish randomly picked IDs.<br>\nI did try using notch filters, but my current LB on tiny networks swing between 0.84~0.85. I couldn't make a definite call on the impact it brings.</p>",
          "votes": null,
          "replies": []
        },
        {
          "id": 1468895,
          "author_name": "anjum48",
          "author_url": "",
          "post_date": "08/12/2021 16:08:01",
          "content": "<p>I did a crude check searching for a spike between 250-350Hz. If the max value is in the 305-307Hz range, I flagged it as True:</p>\n<table>\n<thead>\n<tr>\n<th></th>\n<th>Ch1 Spike</th>\n<th>Ch2 Spike</th>\n<th>Both Spikes</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>True</td>\n<td>525800</td>\n<td>525867</td>\n<td>493779</td>\n</tr>\n<tr>\n<td>False</td>\n<td>34200</td>\n<td>34133</td>\n<td>66221</td>\n</tr>\n</tbody>\n</table>\n<p>Looks like these spikes are very common and probably unrelated to the target. </p>\n<p>It would be interesting to understand what causes them though. There might be some harmonics floating around too.</p>",
          "votes": null,
          "replies": []
        },
        {
          "id": 1469042,
          "author_name": "harshpatel1692",
          "author_url": "",
          "post_date": "08/12/2021 17:29:47",
          "content": "<p>Thanks, this is helpful</p>",
          "votes": null,
          "replies": []
        }
      ]
    },
    {
      "id": 1469115,
      "author_name": "vannak",
      "author_url": "",
      "post_date": "08/12/2021 18:01:15",
      "content": "<p>On page 10 they mention a loud 300Hz signal, that on first read appears to be part of a dampening system. (Search: \"300 Hz\")<br>\n<a href=\"https://dcc.ligo.org/public/0122/P1500260/015/errata_authors_Martynov_PRD_AF.pdf\" target=\"_blank\">https://dcc.ligo.org/public/0122/P1500260/015/errata_authors_Martynov_PRD_AF.pdf</a></p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 1561210,
      "author_name": "zerafachris",
      "author_url": "",
      "post_date": "10/27/2021 12:20:02",
      "content": "<p>Hey All,</p>\n<p>Thank you all for taking part in our competition. The participation has been overwhelmingly positive. We are currently conducting a survey to gauge the demographic and outreach achieved. Kindly spare 2min and fill in this survey <a href=\"https://forms.gle/QP9L16niPexozyhu5\" target=\"_blank\">https://forms.gle/QP9L16niPexozyhu5</a>.</p>\n<p>Thank you all,</p>\n<p>Regards,<br>\nChris</p>",
      "votes": null,
      "replies": []
    }
  ],
  "raw_markdown_by_id": {
    "1464856": "After cleaning the signal with bandpass (30Hz, 500Hz) and notch filters (60Hz and harmonics), I noticed that the US detectors (signal 1 & 2) have spike around 306Hz regardless of the target with it being more prominent when target = 1\n\nID: ffff9a5645\nhttps://ibb.co/rHCvjfN\n\nI'm wondering if anyone else had the same observation and was able to decode/understand more information on this.",
    "1468678": "If it is more prominent when target=1, I wonder if it is a subtle leak?\n\nDoes removing it using a notch filter reduce AUC?",
    "1468875": "I noticed it across 20ish randomly picked IDs.\nI did try using notch filters, but my current LB on tiny networks swing between 0.84~0.85. I couldn't make a definite call on the impact it brings.",
    "1468895": "I did a crude check searching for a spike between 250-350Hz. If the max value is in the 305-307Hz range, I flagged it as True:\n\n| | Ch1 Spike | Ch2 Spike | Both Spikes |\n| ---- | --- | --- | --- |\n| True | 525800 | 525867 | 493779 | \n| False | 34200 | 34133 | 66221 |\n\nLooks like these spikes are very common and probably unrelated to the target. \n\nIt would be interesting to understand what causes them though. There might be some harmonics floating around too.",
    "1469042": "Thanks, this is helpful",
    "1469115": "On page 10 they mention a loud 300Hz signal, that on first read appears to be part of a dampening system. (Search: \"300 Hz\")\nhttps://dcc.ligo.org/public/0122/P1500260/015/errata_authors_Martynov_PRD_AF.pdf",
    "1561210": "Hey All,\n\nThank you all for taking part in our competition. The participation has been overwhelmingly positive. We are currently conducting a survey to gauge the demographic and outreach achieved. Kindly spare 2min and fill in this survey https://forms.gle/QP9L16niPexozyhu5.\n\nThank you all,\n\nRegards,\nChris"
  },
  "source": "meta"
}