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Changes for page ANU Seismic Data Loggers

Last modified by robert on 2025/06/27 16:42
From version 45.1
edited by robert
on 2025/04/24 13:38
Change comment: There is no comment for this version
To version 48.1
edited by robert
on 2025/06/20 12:31
Change comment: There is no comment for this version

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... ... @@ -10,6 +10,19 @@
10 10  )))
11 11  )))
12 12  
13 += Power Considerations =
14 +
15 +Both the LPR-200 (or "Low Power Recorder" 200) and TerraSAWR are designed to use as little power as possible, and more or less use the same amount of power.
16 +
17 +At 100 Hz and with a GPS cable connected these loggers draw about 220 mW of power once the screen is off. Adding a sensor (e.g. a Trillium Compact 120) increases this to approximately 400 mW, or 0.4 volt-amps. So, in theory 7 Ah battery should last about 10 days without a solar panel, but in practice it seems to be a bit closer to 8 which may be due to variability in power drain while in getting GPS locks.
18 +
19 +For very sunny environments (latitudes < 30) a 20V 10 Watt solar panel should have no issue keeping these loggers alive over the summer months, and assuming unobstructed skies should also be fine over winter. However there is no harm in using 20 or even a 40 Watt panel, especially for high latitudes, coastal regions, or areas without a full sky view. In theory up to a 60 Watt solar panel is fine, but we don't recommend anything over 40 Watts and that amount of power is already overkill.
20 +
21 +(% class="box infomessage" %)
22 +(((
23 +Power issues are easy and cheap to solve relative to the cost of your experiment, don't skimp!
24 +)))
25 +
13 13  = Data Card Formatting and Information =
14 14  
15 15  Both the TerraSAWR and LPR-200 require SD Cards to be formatted in FAT32 filesystem. For 64Gb cards it can be difficult to format in FAT32, but [[software >>http://auspass.edu.au/field/fat32cardformatter.exe]]is available. ANU recommend SanDisk Extreme 150 mb/s cards in either 32 or 64Gb size. We strongly discourage using cards larger than 64Gb, and in general smaller cards are less likely to fail. We have also found that "adapter" cards (e.g. SD to microSD) are prone to having write issues and **strongly** advise against them.
... ... @@ -16,25 +16,27 @@
16 16  
17 17  The loggers can be "pre-programmed" with information (e.g. site name, sampling rate, etc) or they can be programmed in the field using the buttons on the logger. To pre-program the cards you simply edit a text file (named "[[ANUSRSetup.txt>>http://auspass.edu.au/field/ANUSRSetup.txt]]" for the LPRs, or "[[tSAWRSetup.txt>>http://auspass.edu.au/field/tSAWRSetup.txt]]" for the TerraSAWRs) and place it in the root directory on the SDCard. When the logger boots up, it will parse and load this information.
18 18  
19 -=== The format for ANUSRSetup.txt / LPR200s will be a single line of text that looks like this: ===
32 +== The format for ANUSRSetup.txt / LPR200s will be a single line of text that looks like this: ==
20 20  
21 21  {{{XXX195G0100010034864 2 }}}
22 22  
23 -corresponding to site XXX19,
24 - network 5G,
25 - sample rate 0100, (i.e. 100 Hz)
26 - "gps interval" 01 (once per hour~-~- don't change),
27 - start mode (always 0),
28 - stop mode (always 0),
29 - seismometer type (3 = broadband (+/- 20V), 2 = Guralp (+/- 10V), 1 = shortperiod (+/- 5V),
30 - and seismometer serial number (4864).
36 +//corresponding to//
31 31  
38 + site **XXX19**,
39 + network **5G**,
40 + sample rate **0100**, (i.e. 100 Hz)
41 + "gps interval" **01** (once per hour~-~- don't change),
42 + start mode (always **0**),
43 + stop mode (always **0**),
44 + seismometer type (**3** = broadband (+/- 20V), 2 = Guralp (+/- 10V), 1 = shortperiod (+/- 5V),
45 + and seismometer serial number (**4864**).
46 +
32 32  (% class="box warningmessage" %)
33 33  (((
34 34  NOTE: the 2 at the very end is for "RECORD ON RESTART". The record on restart option ensures that if the logger dies and is powered back up whilst in the field (due to battery charging cycles or other causes) that the recording will resume. (# of blank spaces before this doesn't matter)
35 35  )))
36 36  
37 -=== The format for TSAWR loggers is shorter: ===
52 +== The format for TSAWR loggers is shorter: ==
38 38  
39 39  (% class="box errormessage" %)
40 40  (((
... ... @@ -53,7 +53,7 @@
53 53   and seismometer serial number (9999).
54 54  
55 55  
56 -=== The formatting process using the logger: ===
71 +== The formatting process using the logger: ==
57 57  
58 58  The process for formatting an SD card within the logger is straightforward. Navigate to the "SD INFORMATION" screen and press ERASE SD CARD. This process may take up to a minute. This will result in erasing all files from the card. Upon starting recording, a new 'seed' will be written containing all the information that the logger has been set with FINISH THIS SECTION
59 59  
... ... @@ -65,7 +65,17 @@
65 65   32Gb card: 122 days @ 250hz or 305 days @ 100hz
66 66  }}}
67 67  
83 +== Default Settings ==
68 68  
85 +As of 2025, the default settings for both LPR (v. 2.7) and TSWAR (v 3.6a) loggers are below. If you're using a broadband instrument, you are essentially good to go without having to program the cards.
86 +
87 +* XX.ANUSR network and station name
88 +* 100 Hz Sample Rate
89 +* 40V pp (or +/- 20 V) gain / Trillium Compact seismometer version
90 +* Record on Restart enabled
91 +
92 +Note that if a user sets the gain incorrectly, this can be fixed later (assuming nothing clipped) by multiplying or dividing by factors of 2. The gain setting can be looked up from the logfile, else you may have to guess from a PSD or other method.
93 +
69 69  = Logger Menus Overview (and setup) =
70 70  
71 71  The same menus are used in both the TSAWR and LPR-200 loggers.
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140 140  
141 141  = Instrument Response =
142 142  
143 -Both the TerraSAWR and LPR-200 use the same ADS1281 analog-to-digital converter chip and are designed to have identical instrument response. Depending on the output sample rate (e.g. 100 Hz, 250 Hz, 500 Hz, 1000 Hz) amplitude response is consistently flat up to ~~100 Hz but phase response can vary above 1 Hz at 100 Hz (or 10 Hz at 250 Hz).
168 +Both the TerraSAWR and LPR-200 use the same ADS1281 analog-to-digital converter chip and are designed to have identical instrument response. Depending on the output sample rate (e.g. 100 Hz, 250 Hz, 1000 Hz) amplitude response is consistently flat up to ~~100 Hz but phase response can vary above 1 Hz at 100 Hz (or 10 Hz at 250 Hz).
144 144  
145 145  The user can choose to apply a 2nd stage "sensor gain" by selecting an instrument type in the setup menu. This effectively selects a 10 Vpp (e.g. short period sensors), 20 Vpp, 40 Vpp (most broadband sensors) regime to match the sensor's sensitivity. This has the effect of doubling amplitude from 10v to 20v, or quadrupling from 10v to 40v. If you have set your sensor correctly (and the signal isn't clipped!) you can "correct" this by simply multiplying your data by 0.5 etc.
146 146  
147 147  Another important thing to note is that the group delay associated with late stage FIR filters is **automatically applied in the logger**, hence there is no need to apply this in the response. These tend to max out at 0.124 seconds for most output sampling rates (0.062 s for 100 Hz).
148 148  
149 -Instrument response can be downloaded from IRIS-NRL (v2) if need be, or by downloading the response of an equivalent sensor at AusPass (e.g. get_stations(level='response') )
174 +Instrument response can be downloaded from IRIS [[Nominal Response Library>>https://ds.iris.edu/ds/nrl/]] if need be, or [[directly from us>>http://auspass.edu.au/data/logger_response]] , or by downloading the response of an equivalent sensor at AusPass (e.g. get_stations(level='response') ).
150 150  
176 +The response info from IRIS-NRL is the "full" version which (in theory!) perfectly describes the data logger's bias on the data. However this is in many way overkill and at the cost of 1) increased metadata size and, more importantly, 2) increased CPU demand in the response removal process. Testing has shown that for signals below 100 Hz, the "full" response offers little to no benefit and can increase the time it takes to remove the response for a 1 hour window of 100Hz data by a factor of x20 or more. For earthquake arrival data this is often negligible, but for data intensive tasks like ambient noise cross-correlations this can be a severe hindrance. Thus we have created a parallel version of this response which removes the SINC and FIR filters completely. These are labelled "fast" in our [[local response archive>>http://auspass.edu.au/data/logger_response]] and essentially truncate response stages 3 onwards into a "fake" decimation step from 1024000 Hz to the desired output samplerate with no filtering whatsoever.
151 151  
152 -= ANU TerraSAWR (Gen 3, FW 3.5a, 2017?- current) =
178 +In the below we show both responses applied to a test signal with a frequency range of 1000 seconds to 100 Hz. The maximum discrepancy in signal is less than 0.01% (1.0001) which is far below what you should expect from the mechanical inconsistencies intrinsic to the sensor itself. Thus, we strongly advise users employ the "fast" version of this response information and it is what we use for our networks by default. If you are recording at 1000 Hz, or care deeply about signals above 100 Hz (so recorded at 250 or 1000 Hz), please use the full response. Any questions, please ask!
153 153  
154 -Words to describe the TSAWR would go here, if needed
180 +[[Testing the "full" and "fast" versions of the ANU data logger response on synthetic 250 Hz data from 1000 seconds to 100 hertz. For all intents and purposes, they are identical.>>image:full_vs_fast.png||data-xwiki-image-style-alignment="center"]]
155 155  
156 156  
183 += ANU TerraSAWR (Gen 3, FW 3.5a, 2017- current) =
157 157  
185 +Not sure there's much left to say
186 +
187 +
188 +
158 158  = ANU LPR-200 (Gen 2, FW 2.6a/2.7a, 2013 - current) =
159 159  
160 160  Ditto the mighty LPR!
161 161  
162 162  
163 -= ANU "ANUSR" (Gen 1, 2003? - 2013?) =
194 += ANU "ANUSR" (Gen 1, 2003? - 2012) =
164 164  
165 -This logger has been retired for a long time and has a different instrument response.
196 +This logger has been retired for a long time and has a different instrument response. It used modular component boards and was powered via an acrylic case of 6 x 6V lantern batteries. There is a somewhat complete one above the CAT lab door if anyone is so inclined to have a look.
166 166  
167 167  
168 168  = References =
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181 181  
182 182  
183 183  
215 +
216 +
217 +
184 184  (% class="box" %)
185 185  (((
186 186  = TerraSAWR Specs =
... ... @@ -195,10 +195,11 @@
195 195  |=Size (L x W x H)|30 x 25 x12cm
196 196  |=Weight (with battery)| 1.9kg (2.5kg)
197 197  |=Battery|(((
198 -Lead-acid 12v, ~~7Ah
232 +Lead-acid 12v, ~~7-9Ah
199 199  
200 200  Rechargeable
201 201  )))
236 +|=Current Firmware|3.5a (Jan 2025)
202 202  
203 203  [[image:terrasawr battery.jpg]]
204 204  )))
... ... @@ -217,11 +217,16 @@
217 217  |=Size (L x W x H)|42 x 34 x17 cm
218 218  |=Weight (no battery)|5.5 kg
219 219  |=Battery|(((
220 -LiFePo4 140Ah
255 +NOW: Any 12v battery with tab connections that will fit (ex. the same TSAWR battery)
221 221  
222 -Rechargeable
257 +DISCONTINUED: LiFePo4 140Ah Rechargeable (shown below).
223 223  )))
259 +|=Current Firmware|(((
260 +2.6a (old GPS modules) / 2.7a
224 224  
262 +Jan 2025
263 +)))
264 +
225 225  [[image:LPR battery.jpg]]
226 226  )))
227 227  )))
full_vs_fast.png
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