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Last modified by robert on 2026/02/27 19:58
From version 102.1
edited by robert
on 2026/02/16 17:44
Change comment: There is no comment for this version
To version 104.2
edited by robert
on 2026/02/17 12:37
Change comment: There is no comment for this version

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... ... @@ -418,9 +418,9 @@
418 418  
419 419  = Instrument Response =
420 420  
421 -We are aware that there are various different published responses for these instruments and trust very few of them. One has to be careful with how polarity is handled between groups as well, as well as if one is working in integer counts (the ANSIR default) or mV (why anyone uses this is beyond our comprehension). The response information published below is in counts and seems to fit well in huddle tests. Note that these all appear to be sample rate insensitive, and the IGU data has been inverted (multiplied by -1) as described here: [[5Hz Node Polarity Issues>>https://auspass.edu.au/xwiki/bin/view/Data/AusPass%20Data/#HSmartSoloNodePolarityIssues]]
421 +We are aware that there are various different published responses for these instruments and trust very few of them. One has to be careful with how polarity is handled between groups as well, and if one is working in integer counts (the ANSIR default) or mV (unclear why anyone would use this as it makes file sizes enormous). The response information published below is in **counts** and seems to fit well in huddle tests. Note that the response is the same for all channels and all units (e.g. there are no bespoke calibrations!), all appear to be sample rate insensitive, and the IGU data has been inverted (multiplied by -1) as described here: [[5Hz Node Polarity Issues>>https://auspass.edu.au/xwiki/bin/view/Data/AusPass%20Data/#HSmartSoloNodePolarityIssues]]
422 422  
423 -== IGU16-3C ==
423 +== IGU 16HR-3C ==
424 424  
425 425   '16HR3C': {'poles':[(-22.211059+22.217768j), (-22.211059-22.217768j)],
426 426   'zeros':[0j, 0j],
... ... @@ -427,12 +427,14 @@
427 427   'gain':1,
428 428   'sensitivity': 257019225.55108312}
429 429  
430 -[[Caption>>image:IGU16_Z_huddle.png]]
430 +[[X axis is samples (.01 s), Y axis is velocity (m/s), 0.5-5 Hz filter>>image:IGU16_Z_huddle.png]]
431 431  
432 -[[Caption>>image:IGU16_N_huddle.png]]
432 +[[X axis is samples (.01 s), Y axis is velocity (m/s), 0.5-5 Hz filter>>image:IGU16_N_huddle.png]]
433 433  
434 -== IGU16-1C ==
434 +== IGU 16-1C ==
435 435  
436 +The 1C nodes seem to have a slightly different response to the 3C (TBA)
437 +
436 436  == BD3C-5 ==
437 437  
438 438   'BD3C': {'poles':[(-1720.4+0j), (-1.2+0.9j), (-1.2-0.9j)],
... ... @@ -440,11 +440,13 @@
440 440   'gain':1.69726e-05,
441 441   'sensitivity': 702651512.6046528}
442 442  
445 +*image TBA but they have been created in the past~-~- we are 100% confident our published responses are correct
446 +
443 443  == Horizontal noise & how to avoid ==
444 444  
445 445  The 5 Hz nodes are susceptible to horizontal noise due to the placement of geophones in the units, **but this can be mitigated by completely burying the units flush with the ground.** In the below example, the node was set on the floor of our basement set on its plastic carrying case support. As such the amount of horizontal noise noticeably increases above ~~ 10Hz.
446 446  
447 -[[Power spectrum huddle test vs a CMG-6TD (S1) and TC120/Centaur combo, all filtered 0.5-5 Hz. The N and E channels have excess noise above 10Hz due to "sticking up" out of the ground.>>image:IGU16_spectrum.png]]
451 +[[Power spectrum huddle test vs a CMG-6TD (S1) and TC120/Centaur combo. The N and E channels have excess noise above 10Hz due to "sticking up" out of the ground.>>image:IGU16_spectrum.png]]
448 448  
449 449  = **Cleaning** =
450 450