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Changes for page AusPass Data

Last modified by robert on 2026/02/12 14:01
From version 15.2
edited by robert
on 2025/12/16 21:57
Change comment: There is no comment for this version
To version 15.3
edited by robert
on 2026/01/16 11:29
Change comment: There is no comment for this version

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46 46  
47 47  Soon we will also begin hosting regionally specific catalogs with full phase picks.
48 48  
49 -= SmartSolo Node Polarity bug (IGU-16HR only) =
49 += SmartSolo Node Polarity Issues =
50 50  
51 +There has been a lot of confusion about the polarity of the IGU-16HR (1C and 3C) data, as well as the BD3C-5 data over the years.
52 +
53 +(% class="box errormessage" %)
54 +(((
55 +ALL IGU-16HR channels have negative polarity relative to "standard" FDSNXML convention (positive down = -90 degrees, positive north = 0 degrees, positive east = 90 degrees). Freshly exported data requires a -1 multiplier relative to be "correct" relative to what you're likely expecting.
56 +)))
57 +
58 +(% class="box infomessage" %)
59 +(((
60 +BD3C-5 channels are "normal" and consistent with usual high gain seismometers. These sensors do not require any polarity flips.
61 +)))
62 +
63 +After much consternation was have finally tested this ourselves in a controlled environment, and have also consulted various agencies. We are now certain the above notices to be correct.
64 +
65 +[[Arrivals showing the polarity of various instrument types (courtesy of the China Earthquake Administration). Note that the IGU-HR3C are inverted relative to the BD3C and CMG40T. >>image:Weixin Image_20260115150150_19_1185.png||alt="Arrivals showing various sensors. The HR3C channels are inverted."]]
66 +
51 51  In[[ late 2023 it was discovered>>https://epic.earthscope.org/content/smartsolo-archives-flipped-polarity-igu-16hr-3c-5hz]] that the vertical Z channel of **the IGU-16HR short period **SmartSolo nodes is actually inverted relative to the standard expectation of "positive up" (vertical axis dip = -90). EarthScope's solution was to add a -1 multiplier to the //response data.// Because we have a much smaller volume of this data to fix, and far less of it already distributed prior to this announcement, we have opted to do the opposite; e.g. we invert the //raw data// because the data is what is wrong; not the response.
52 52  
53 53  **In late 2025 we also discovered that the horizontal (N and E) channels are ALSO flipped! Data downloaded before Friday 5 December 2025 is affected- multiply your DH[NE] channels by -1 if you have already downloaded them.**
Weixin Image_20260115150150_19_1185.png
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1 +XWiki.robert
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