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

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1 -=== **Silixa iDAS Setup Manual for Reoccupying/Duplicating Experiment** ===
1 += **DAS Data Collection System** =
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 +
3 3  ----
4 4  
5 -==== **General Information** ====
34 += **DAS Metadata Schema** =
6 6  
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 +
7 7  * **Experiment Name:** ~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~__
8 8  * **Local Date:** ~_~_~_~_/~_~__**/202**
9 9  * **Local Time:** ~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~__
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183 183  
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317 +