Changes for page Integrated Distributed Acoustic Sensing (iDAS)

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	1	+= **What is iDAS?** =
	2	+
	3	+**iDAS** stands for **Integrated Distributed Acoustic Sensing**. This advanced system utilizes the principle of Rayleigh backscattering in optical fibers to measure strain rates along the fiber's length. It's a cutting-edge technology predominantly used in fields like geophysics, where it's crucial for monitoring seismic activities, as well as in industrial applications like pipeline monitoring and security systems.
	4	+
	5	+=== **Safety first!**
	6	+ ===
	7	+
	8	+(% class="box warningmessage" %)
	9	+The iDAS uses a Class 1 laser, which is generally considered safe for most applications. However, direct exposure to the eye should be avoided to prevent any risk of eye injury.
	10	+\\Cables and fibers may create tripping hazards. Ensure that the routing of cables is done in a way that minimizes the risk of accidents.
	11	+
	12	+----
	13	+
	14	+=== **System Components** ===
	15	+
	16	+**Interrogator Unit**
	17	+
	18	+* The heart of the iDAS system, this unit contains the laser source, a detector for capturing backscattered light, and electronics to process this signal. It's critical for generating and interpreting the data collected by the optical fiber.
	19	+
	20	+**Optical Fiber**
	21	+
	22	+* This component acts as a long, distributed sensor. Strain rates along this fiber are what the iDAS system measures and analyzes.
	23	+
	24	+**Data Acquisition Software**
	25	+
	26	+* This software interfaces with the interrogator unit, allowing users to configure acquisition parameters, initiate data capture, and process the collected data.
	27	+
	28	+= =
	29	+
	30	+= =
	31	+
1	1	= **DAS Data Collection System** =
2	2
3	3	==== **1. Interrogator Unit** ====
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29	29	* **Physical Location Determination:** The physical locations of these channels are ascertainable through methods like tap tests and GPS tracking.
30	30	* **Metadata for Channels:** Each channel or group of channels has its own metadata block, detailing specifics like location and properties.
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32		-=== ===
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	64	+[[image:1706489800616-982.png]]
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	66	+
	67	+
	68	+[[image:1706488566274-805.png]]
	69	+
34	34	----
35	35
	72	+= **DAS Metadata Schema** =
	73	+
	74	+==== **1. Interrogator** ====
	75	+
	76	+* **Required:** Interrogator ID, manufacturer, model.
	77	+* **Optional:** Serial number, firmware version.
	78	+
	79	+==== **2. Acquisition Parameters** ====
	80	+
	81	+* **Required:** Interrogator ID, acquisition ID, unit of measure, acquisition start and end time, acquisition sample rate, gauge length, number of channels, spatial sampling interval.
	82	+* **Optional:** Pulse rate, pulse width.
	83	+
	84	+==== **3. Overview** ====
	85	+
	86	+* **Required:** Network code, location, start date, end date, point of contact.
	87	+* **Optional:** Digital Object Identifier (DOI), purpose of data collection, funding agency.
	88	+
	89	+==== **4. Cable Information** ====
	90	+
	91	+* **Required:** Cable ID, cable bounding box.
	92	+* **Optional:** Cable owner, cable installation date, cable characteristics.
	93	+
	94	+==== **5. Fiber Information ('Native format')** ====
	95	+
	96	+* **Required:** Cable ID, fiber ID, fiber geometry, fiber mode, fiber refraction index.
	97	+* **Optional:** Fiber optical length, fiber start and end location, fiber one-way attenuation, fiber winding angle.
	98	+
	99	+==== **6. Channel Group** ====
	100	+
	101	+* **Required:** Interrogator ID, acquisition ID, channel group ID, cable ID, fiber ID, coordinate generation date.
	102	+* **Optional:** Location method, coordinate reference frame, first/last usable channel ID, uncertainty of various coordinates (x, y, latitude, longitude, elevation, depth, strike, dip).
	103	+
	104	+==== **7. Channel** ====
	105	+
	106	+* **Required:** Channel group ID, channel ID, coordinates (x, y, latitude, longitude).
	107	+* **Optional:** Elevation above sea level, depth below surface, distance along fiber, strike, dip.
	108	+
	109	+----
	110	+
36	36	=== ===
37	37
38	38	= **Pre-processing Steps for DAS Data (2.5 months, 90 TB)** =
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