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Changes for page ANU Seismic Data Loggers

Last modified by robert on 2025/09/16 13:22
From version 66.1
edited by robert
on 2025/09/16 13:19
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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... ... @@ -14,9 +14,9 @@
14 14  
15 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 16  
17 -At 100 Hz and with a GPS cable connected these loggers draw about 220 mW of power once the screen is off (higher sample rates draw more power but only marginally, < 5 mW). 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.
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 18  
19 -For very sunny environments (latitudes < 30) a 20 Volts 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.
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 20  
21 21  (% class="box infomessage" %)
22 22  (((
... ... @@ -23,17 +23,6 @@
23 23  Power issues are easy and cheap to solve relative to the cost of your experiment, don't skimp!
24 24  )))
25 25  
26 -(% class="wikigeneratedid" %)
27 -In the case of an LPR, there is a large compartment for housing an internal battery, able to accommodate anything from a 10-30Ah battery. To use a standard lead acid battery with a positive and negative terminal, a 6 pin adaptor must be used. This ensures the voltage from the external power port (pins A and C) connect to the battery and ensure the system actually recharges. (See [[Peripheral Equipment>>doc:Instrumentation.Peripheral Equipment.WebHome]] for a more comprehensive overview of this kind of setup)
28 -
29 -= GPS Considerations =
30 -
31 -GPS is required for the data to have accurate timestamps. A standard 3-5V 1575.42 Mhz coaxial cable works fine and can be found for relatively cheap (e.g. [[https:~~/~~/www.elecbee.com/en-3555-gps-antenna-bnc-male-for-garmin-gps-120120xl125-sounder-with-cable-2m) >>https://www.elecbee.com/en-3555-gps-antenna-bnc-male-for-garmin-gps-120120xl125-sounder-with-cable-2m]]
32 -
33 -The TerraSAWR has a built-in GPS but this doesn't work as well, especially if the logger is (wisely) buried. **The LPR does NOT have a built-in GPS antenna, so an external antenna is mandatory.**
34 -
35 -In a pinch, a severed or broken antenna can be mended back together relatively easily by non-experts. Even stripping the wire and twisting it back together by hand on site is possible!
36 -
37 37  = Data Card Formatting and Information =
38 38  
39 39  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.
... ... @@ -40,8 +40,7 @@
40 40  
41 41  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.
42 42  
43 -(% class="wikigeneratedid" id="HTheformatforANUSRSetup.txt2FLPR200swillbeasinglelineoftextthatlookslikethis:" %)
44 -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: ==
45 45  
46 46  {{{XXX195G0100010034864 2 }}}
47 47  
... ... @@ -61,8 +61,7 @@
61 61  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)
62 62  )))
63 63  
64 -(% class="wikigeneratedid" id="HTheformatforTSAWRloggersisshorter:" %)
65 -The format for TSAWR loggers is shorter:
52 +== The format for TSAWR loggers is shorter: ==
66 66  
67 67  (% class="box errormessage" %)
68 68  (((
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81 81   and seismometer serial number (9999).
82 82  
83 83  
84 -(% class="wikigeneratedid" id="HTheformattingprocessusingthelogger:" %)
85 -The formatting process using the logger:
71 +== The formatting process using the logger: ==
86 86  
87 87  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
88 88  
... ... @@ -100,7 +100,7 @@
100 100  
101 101  * XX.ANUSR network and station name
102 102  * 100 Hz Sample Rate
103 -* 40 Vpp (or +/- 20 V) gain / Trillium Compact seismometer version
89 +* 40V pp (or +/- 20 V) gain / Trillium Compact seismometer version
104 104  * Record on Restart enabled
105 105  
106 106  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.
... ... @@ -115,8 +115,8 @@
115 115  
116 116  This menu also displays the firmware version, battery, external, and solar voltages, and the temperature of the system.
117 117  
118 -* Check that all //Initialisation Parameters// are marked as successful.
119 -* Check that solar voltage is above 10 V in the software, or preferrably physically check that the battery's voltage is increasing via a DMM.
104 +* Check all Initialisation Parameters are marked as successful.
105 +* Check that solar voltage is above 10 V, otherwise the station will not last long.
120 120  
121 121  == Live Seismometer Data ==
122 122  
... ... @@ -130,7 +130,7 @@
130 130  
131 131  This menu displays the status of the stations' GPS connection. The screen lists; UTC time, UTC date, latitude, longitude, altitude, number of satellite connections, and SNR.
132 132  
133 -* Check that the station is connected to satellites. 3 or more should be perfectly adequate to keep time.
119 +* Check that the station is connected to satellites
134 134  
135 135  == SD Information ==
136 136  
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148 148  
149 149  The seismometer model and serial number (up to 10 characters) can be set. Seismometer model options include:
150 150  
151 -* Trillium Compact (same for 20s and 120s models)
137 +* Trillium Compact (same for 20 and 120)
152 152  * CMG - 3ESP
153 153  * Guralp 40T
154 154  * LE-3D Lite
... ... @@ -163,7 +163,7 @@
163 163  
164 164  (% class="box errormessage" %)
165 165  (((
166 -Again, ensure the 'RECORD ON RESTART' option is marked with a cross (the default setting). This ensures that the logger will record any time it receives enough power!
152 +NOTE: Ensure the 'RECORD ON RESTART' option is marked with a cross.
167 167  )))
168 168  
169 169  (% class="wikigeneratedid" %)
... ... @@ -179,64 +179,31 @@
179 179  
180 180  = Instrument Response =
181 181  
182 -Both the TerraSAWR and LPR-200 use the same ADS1281 analog-to-digital converter chip and are designed to have identical instrument response. The ADC (analog to digital) chip in both loggers originally samples at 1024000 Hz and downsamples towards the output data rate via a 5th order SINC filter, then another four FIR filters. If the output is below 250 Hz, a final "pure" /5 decimation is done without any sort of FIR filter (for better or worse!).
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).
183 183  
184 -In the logger's menu, 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. This gain manifests itself in stage 2 in the response information.
170 +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.
185 185  
186 -//(The 600+ Stage 3 SINC coefficients during the initial 1024k > 16k decimation were left off as they slowed down the process x10 and contribute at most 0.3 db amplitude and 0.31 ms phase delay discrepancies, and primarily only to frequencies near the nyquist. If for some reason you want to add this phase manually we can share the parameters with you.)//
172 +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).
187 187  
188 -You might notice that the response information may come in two versions. The response from our website (see link below) includes the 2nd "sensor gain" stage for clarity. e.g. here is a Trillium Compact 120 & ANU Logger response
189 -
190 -##Channel Response
191 - From M/S (Velocity) to COUNTS ()
192 - Overall Sensitivity: 3.95452e+08 defined at 1.000 Hz
193 - 8 stages:
194 - Stage 1: PolesZerosResponseStage from M/S to V, gain: 754.3
195 - Stage 2: ResponseStage from V to V, gain: 0.25
196 - Stage 3: CoefficientsTypeResponseStage from V to COUNTS, gain: 2.09715e+06
197 - Stage 4: FIRResponseStage from COUNTS to COUNTS, gain: 1
198 - Stage 5: FIRResponseStage from COUNTS to COUNTS, gain: 1
199 - Stage 6: FIRResponseStage from COUNTS to COUNTS, gain: 0.99998
200 - Stage 7: FIRResponseStage from COUNTS to COUNTS, gain: 1##
201 -
202 -
203 -However, if retrieving from AusPass or IRIS, the 2nd "sensor gain" stage is combined with the logger gain. This has no affect, but you may detect that the former Stage 2 V->V ResponseStage has been merged into the Stage 3 gain.
204 -
205 -##Channel Response
206 - From M/S (Velocity) to COUNTS ()
207 - Overall Sensitivity: 3.9546e+08 defined at 1.000 Hz
208 - 6 stages:
209 - Stage 1: PolesZerosResponseStage from M/S to V, gain: 754.3
210 - Stage 2: CoefficientsTypeResponseStage from V to COUNTS, gain: 524288
211 - Stage 3: FIRResponseStage from COUNTS to COUNTS, gain: 1
212 - Stage 4: FIRResponseStage from COUNTS to COUNTS, gain: 1
213 - Stage 5: FIRResponseStage from COUNTS to COUNTS, gain: 0.99998
214 - Stage 6: FIRResponseStage from COUNTS to COUNTS, gain: 1##
215 -
216 -
217 -For the most part, the data logger response essentially flat when the samplerate output is set to 100 Hz or less and for seismological purposes is likely to be impossible to detect below 20 Hz regardless.
218 -
219 219  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') ).
220 220  
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.
221 221  
222 -[[Amplitude and phase response for ANU logger at 50 Hz>>image:ANU_50hz_response.png||data-xwiki-image-style-alignment="center" height="356" width="475"]]
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!
223 223  
224 -[[Amplitude and phase response for ANU logger at 100 Hz>>image:ANU_100hz_response.png||data-xwiki-image-style-alignment="center" height="355" width="473"]]
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"]]
225 225  
226 -[[Amplitude and phase response for ANU logger at 250 Hz>>image:ANU_250hz_response.png||data-xwiki-image-style-alignment="center" height="359" width="479"]]
227 227  
228 -[[Amplitude and phase response for ANU logger at 1000 Hz>>image:ANU_1000hz_response.png||data-xwiki-image-style-alignment="center" height="367" width="489"]]
183 += ANU TerraSAWR (Gen 3, FW 3.5a, 2017- current) =
229 229  
185 +Not sure there's much left to say
230 230  
231 -[[Huddle test comparing a Trillium Compact 120 + TerraSAWR vs a Trillium Compact 120 + Nanometrics Centaur (M8.AUANU) at 100 Hz>>image:TC120_ANU_vs_CENTAUR.png||data-xwiki-image-style-alignment="center"]]
232 232  
233 -= ANU TerraSAWR (Gen 3, FW 3.5a, 2014- current) =
234 234  
235 -Earliest known model is dated July 2014 (though first deployed in 2019) and our current flagship model. Lightweight and small.
189 += ANU LPR-200 (Gen 2, FW 2.6a/2.7a, 2013 - current) =
236 236  
237 -= ANU LPR-200 (Gen 2, FW 2.6a/2.7a, 2011 - current) =
191 +Ditto the mighty LPR!
238 238  
239 -Earliest known model is dated May 2011 (but first deployed November 2012) and still in use today. Potentially capable of housing much larger batteries than the TSAWR due to the larger cavity space.
240 240  
241 241  = ANU "ANUSR" (Gen 1, 2003? - 2012) =
242 242  
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262 262  
263 263  
264 264  
265 -
266 -
267 -
268 -
269 -
270 -
271 -
272 -
273 -
274 -
275 -
276 -
277 -
278 -
279 -
280 -
281 -
282 -
283 283  (% class="box" %)
284 284  (((
285 285  = TerraSAWR Specs =
... ... @@ -330,13 +330,4 @@
330 330  [[image:LPR battery.jpg]]
331 331  )))
332 332  )))
333 -
334 -
335 -
336 -
337 -
338 -
339 -
340 -
341 -
342 342  )))
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