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Last modified by robert on 2024/05/17 16:52
From version 6.4
edited by Sima Mousavi
on 2024/01/29 13:16
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To version 6.2
edited by Sima Mousavi
on 2024/01/29 11:57
Change comment: There is no comment for this version

Summary

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1 -= **DAS Data Collection System** =
1 +=== **Silixa iDAS Setup Manual for Reoccupying/Duplicating Experiment** ===
2 2  
3 -==== **1. Interrogator Unit** ====
4 -
5 -* **Function:** The interrogator unit is the core component of a DAS system. It sends laser pulses through the optical fiber and measures the backscattered light.
6 -* **Recording Information:** It records various settings such as the optical system configurations, spatial sampling rates, and the duration of data acquisition.
7 -* **Multiple Interrogators:** More than one interrogator may be used in an experiment. Each unit should have a unique identifier and is described in its respective metadata block.
8 -
9 -==== **2. Surface Installation** ====
10 -
11 -* **Cable Arrangement:** The optical fiber cable can be a single long continuous cable or multiple cables with connectors, used across different installation environments.
12 -* **Cable Types:** Cables may vary in construction types based on the installation environment.
13 -* **Geographical Metadata:** Parameters related to geographical location are specified for easy searchability in databases.
14 -
15 -==== **3. Fiber Optic Cable** ====
16 -
17 -* **Cable Composition:** Several optical fibers may be enclosed within one cable.
18 -* **Metadata Identification:** The metadata identifies each individual fiber used in the acquisition, including its intrinsic properties.
19 -
20 -==== **4. Installation Environments** ====
21 -
22 -* **Shallow Burial:** The cable can be shallowly buried.
23 -* **In-Conduit Installation:** The cable can also be installed within a conduit.
24 -* **Water Installation:** Suitable for underwater environments.
25 -
26 -==== **5. Channels** ====
27 -
28 -* **Sensor Distribution:** Channels represent sensors distributed along the fiber array at fixed intervals.
29 -* **Physical Location Determination:** The physical locations of these channels are ascertainable through methods like tap tests and GPS tracking.
30 -* **Metadata for Channels:** Each channel or group of channels has its own metadata block, detailing specifics like location and properties.
31 -
32 32  ----
33 33  
34 -= **DAS Metadata Schema** =
5 +==== **General Information** ====
35 35  
36 -==== **1. Interrogator** ====
37 -
38 -* **Required:** Interrogator ID, manufacturer, model.
39 -* **Optional:** Serial number, firmware version.
40 -
41 -==== **2. Acquisition Parameters** ====
42 -
43 -* **Required:** Interrogator ID, acquisition ID, unit of measure, acquisition start and end time, acquisition sample rate, gauge length, number of channels, spatial sampling interval.
44 -* **Optional:** Pulse rate, pulse width.
45 -
46 -==== **3. Overview** ====
47 -
48 -* **Required:** Network code, location, start date, end date, point of contact.
49 -* **Optional:** Digital Object Identifier (DOI), purpose of data collection, funding agency.
50 -
51 -==== **4. Cable Information** ====
52 -
53 -* **Required:** Cable ID, cable bounding box.
54 -* **Optional:** Cable owner, cable installation date, cable characteristics.
55 -
56 -==== **5. Fiber Information ('Native format')** ====
57 -
58 -* **Required:** Cable ID, fiber ID, fiber geometry, fiber mode, fiber refraction index.
59 -* **Optional:** Fiber optical length, fiber start and end location, fiber one-way attenuation, fiber winding angle.
60 -
61 -==== **6. Channel Group** ====
62 -
63 -* **Required:** Interrogator ID, acquisition ID, channel group ID, cable ID, fiber ID, coordinate generation date.
64 -* **Optional:** Location method, coordinate reference frame, first/last usable channel ID, uncertainty of various coordinates (x, y, latitude, longitude, elevation, depth, strike, dip).
65 -
66 -==== **7. Channel** ====
67 -
68 -* **Required:** Channel group ID, channel ID, coordinates (x, y, latitude, longitude).
69 -* **Optional:** Elevation above sea level, depth below surface, distance along fiber, strike, dip.
70 -
71 -----
72 -
73 -=== ===
74 -
75 -= **Pre-processing Steps for DAS Data (2.5 months, 90 TB)** =
76 -
77 -1. (((
78 -**Create a Deployment Log**
79 -
80 -* Document key details like photonics settings, duration of data collection, instances of hard disk failure, power outages, etc.
81 -)))
82 -1. (((
83 -**Generate Geographic Coordinates**
84 -
85 -* Assign latitude and longitude coordinates to each DAS channel for spatial referencing.
86 -)))
87 -1. (((
88 -**Data Conversion**
89 -
90 -* Convert the raw DAS time series data from counts to strain rate, which is more meaningful for seismic analysis.
91 -)))
92 -1. (((
93 -**Data Decimation**
94 -
95 -* Reduce the sampling rate from 1000 Hz to 100 Hz. This step is essential to manage data volume and focus on frequencies of interest for seismic activities.
96 -)))
97 -1. (((
98 -**Extract Specific Time Series**
99 -
100 -* Isolate time series data of special interest, such as those related to earthquake events, for detailed analysis.
101 -)))
102 -1. (((
103 -**Data Hosting**
104 -
105 -* Store the processed data on Research School of Earth Sciences (RSES) clusters and the National Computational Infrastructure (NCI) for accessibility and further analysis.
106 -)))
107 -1. (((
108 -**Extract Data and Instrument Response from Seismic Nodes**
109 -
110 -* Retrieve both the raw data and the corresponding instrument response characteristics for accurate interpretation of the seismic signals.
111 -)))
112 -1. (((
113 -**Long-term Archiving and Data Sharing**
114 -
115 -* Ensure that the data is archived in a format and location that supports long-term preservation and accessibility, such as the AuScope Distributed Acoustic Sensing (DAS) Collection.
116 -)))
117 -1. (((
118 -**Data Access and Record Keeping**
119 -
120 -* Maintain records and access paths (e.g., NCI local file path) for the data, including metadata and other associated records, to facilitate future research and data sharing.
121 -)))
122 -
123 -=== ===
124 -
125 -=== ===
126 -
127 -=== ===
128 -
129 -=== ===
130 -
131 -=== ===
132 -
133 -----
134 -
135 -= **Silixa iDAS Setup Manual for Reoccupying/Duplicating Experiment** =
136 -
137 -= **General Information** =
138 -
139 139  * **Experiment Name:** ~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~__
140 140  * **Local Date:** ~_~_~_~_/~_~__**/202**
141 141  * **Local Time:** ~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~__
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314 314  
315 315  
316 316  
317 -