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Changes for page ANU Seismic Data Loggers

Last modified by robert on 2025/09/16 13:22
From version 58.1
edited by robert
on 2025/08/06 18:34
Change comment: There is no comment for this version
To version 65.1
edited by robert
on 2025/09/16 13:18
Change comment: There is no comment for this version

Summary

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... ... @@ -26,6 +26,14 @@
26 26  (% class="wikigeneratedid" %)
27 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 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 +
29 29  = Data Card Formatting and Information =
30 30  
31 31  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.
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32 32  
33 33  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.
34 34  
35 -== The format for ANUSRSetup.txt / LPR200s will be a single line of text that looks like this: ==
43 +=== The format for ANUSRSetup.txt / LPR200s will be a single line of text that looks like this: ===
36 36  
37 37  {{{XXX195G0100010034864 2 }}}
38 38  
... ... @@ -52,7 +52,7 @@
52 52  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)
53 53  )))
54 54  
55 -== The format for TSAWR loggers is shorter: ==
63 +=== The format for TSAWR loggers is shorter: ===
56 56  
57 57  (% class="box errormessage" %)
58 58  (((
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71 71   and seismometer serial number (9999).
72 72  
73 73  
74 -== The formatting process using the logger: ==
82 +=== The formatting process using the logger: ===
75 75  
76 76  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
77 77  
... ... @@ -104,8 +104,8 @@
104 104  
105 105  This menu also displays the firmware version, battery, external, and solar voltages, and the temperature of the system.
106 106  
107 -* Check all Initialisation Parameters are marked as successful.
108 -* Check that solar voltage is above 10 V, otherwise the station will not last long.
115 +* Check that all //Initialisation Parameters// are marked as successful.
116 +* 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.
109 109  
110 110  == Live Seismometer Data ==
111 111  
... ... @@ -119,7 +119,7 @@
119 119  
120 120  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.
121 121  
122 -* Check that the station is connected to satellites
130 +* Check that the station is connected to satellites. 3 or more should be perfectly adequate to keep time.
123 123  
124 124  == SD Information ==
125 125  
... ... @@ -152,7 +152,7 @@
152 152  
153 153  (% class="box errormessage" %)
154 154  (((
155 -NOTE: Ensure the 'RECORD ON RESTART' option is marked with a cross.
163 +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!
156 156  )))
157 157  
158 158  (% class="wikigeneratedid" %)
... ... @@ -168,30 +168,57 @@
168 168  
169 169  = Instrument Response =
170 170  
171 -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.
179 +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!).
172 172  
173 -{{info}}
174 -The Stage 3 SINC coefficients (600+) during the initial 1024k > 16k decimation were left off as they slowed down the process x10 and contribute very little (< 0.3 db, < 0.31 ms) to the end result
175 -{{/info}}
181 +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.
176 176  
177 -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.
183 +//(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.)//
178 178  
179 -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') ).
185 +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
180 180  
187 +##Channel Response
188 + From M/S (Velocity) to COUNTS ()
189 + Overall Sensitivity: 3.95452e+08 defined at 1.000 Hz
190 + 8 stages:
191 + Stage 1: PolesZerosResponseStage from M/S to V, gain: 754.3
192 + Stage 2: ResponseStage from V to V, gain: 0.25
193 + Stage 3: CoefficientsTypeResponseStage from V to COUNTS, gain: 2.09715e+06
194 + Stage 4: FIRResponseStage from COUNTS to COUNTS, gain: 1
195 + Stage 5: FIRResponseStage from COUNTS to COUNTS, gain: 1
196 + Stage 6: FIRResponseStage from COUNTS to COUNTS, gain: 0.99998
197 + Stage 7: FIRResponseStage from COUNTS to COUNTS, gain: 1##
181 181  
182 -[[Amplitude and phase response for ANU logger at 50 Hz>>image:ANU_50hz_response.png]]
183 183  
184 -[[Amplitude and phase response for ANU logger at 100 Hz>>image:ANU_100hz_response.png]]
200 +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.
185 185  
202 +##Channel Response
203 + From M/S (Velocity) to COUNTS ()
204 + Overall Sensitivity: 3.9546e+08 defined at 1.000 Hz
205 + 6 stages:
206 + Stage 1: PolesZerosResponseStage from M/S to V, gain: 754.3
207 + Stage 2: CoefficientsTypeResponseStage from V to COUNTS, gain: 524288
208 + Stage 3: FIRResponseStage from COUNTS to COUNTS, gain: 1
209 + Stage 4: FIRResponseStage from COUNTS to COUNTS, gain: 1
210 + Stage 5: FIRResponseStage from COUNTS to COUNTS, gain: 0.99998
211 + Stage 6: FIRResponseStage from COUNTS to COUNTS, gain: 1##
186 186  
187 -[[Amplitude and phase response for ANU logger at 250 Hz>>image:ANU_250hz_response.png]]
188 188  
214 +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.
189 189  
190 -[[Amplitude and phase response for ANU logger at 1000 Hz>>image:ANU_1000hz_response.png]]
216 +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') ).
191 191  
192 192  
193 -[[Huddle test comparing a Trillium Compact 120 + TerraSAWR vs a Trillium Compact 120 + Nanometrics Centaur (M8.AUANU)>>image:TC120_ANU_vs_CENTAUR.png||data-xwiki-image-style-alignment="center"]]
219 +[[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"]]
194 194  
221 +[[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"]]
222 +
223 +[[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"]]
224 +
225 +[[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"]]
226 +
227 +
228 +[[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"]]
229 +
195 195  = ANU TerraSAWR (Gen 3, FW 3.5a, 2014- current) =
196 196  
197 197  Earliest known model is dated July 2014 (though first deployed in 2019) and our current flagship model. Lightweight and small.
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234 234  
235 235  
236 236  
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278 +
237 237  (% class="box" %)
238 238  (((
239 239  = TerraSAWR Specs =
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284 284  [[image:LPR battery.jpg]]
285 285  )))
286 286  )))
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336 +
287 287  )))