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公开(公告)号：US09909903B2
公开(公告)日：2018-03-06
申请号：US13441802
申请日：2012-04-06
CPC分类号： G01H9/004 , G01D1/00 , G01D1/02 , G01D5/35303 , G01D5/35306 , G01D5/35312 , G01D5/35329 , G01D5/35345 , G01D5/35358 , G01D5/35361 , G01D5/35367 , G01D5/35387 , G01D5/3539 , G01D5/35393 , G01D5/35396
摘要： The application describes methods and apparatus for distributed fiber sensing, especially distributed acoustic/strain sensing. The method involves launching at least first and second pulse pairs into an optical fiber, the first and second pulse pairs having the same frequency configuration as one another and being generated such that the phase relationship of the pulses of the first pulse pair has a predetermined relative phase difference to the phase relationship of the pulses of the second pulse pair. In one embodiment there is a frequency difference between the pulses in a pulse pair which is related to the launch rate of the pulse pairs. In another embodiment the phase difference between the pulses in a pair is varied between successive launches. In this way an analytic version of the backscatter interference signal can be generated within the baseband of the sensor.
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公开(公告)号：US06480635B1
公开(公告)日：2002-11-12
申请号：US09554559
申请日：2000-05-15
IPC分类号： G02B627
CPC分类号： G02B6/447
摘要： In order to identify a fiber optic cable (10) a beam (14) of polarized light is caused to pass down the cable to a first site (A) at which an electromagnetic field (24) is applied to the cable (10). The electromagnetic field (24) traverses the cable (10) in an essentially transverse direction and has a time-varying component orientated along the length of the cable (10) at the first site (A), with the component varying so that the line integral thereof along the cable (10) is non-zero. This results in a variation in the polarization of the light, which can then be detected by a polarization discriminator (20) at a second site (B), thereby to identify the cable (10).
摘要翻译： 为了识别光纤电缆（10），使得偏振光束（14）将电缆穿过第一位置（A），在第一位置（A）处将电磁场（24）施加到电缆（10）。 电磁场（24）在基本横向上横穿电缆（10），并且具有沿第一位置（A）处的电缆（10）的长度方向定向的时变分量，其中部件变化，使得线 沿着电缆（10）的整体不为零。 这导致光的偏振变化，其然后可以在第二位置（B）处由偏振鉴别器（20）检测，从而识别电缆（10）。
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公开(公告)号：US09435668B2
公开(公告)日：2016-09-06
申请号：US13441798
申请日：2012-04-06
CPC分类号： G01H9/004 , G01D1/00 , G01D1/02 , G01D5/35303 , G01D5/35306 , G01D5/35312 , G01D5/35329 , G01D5/35345 , G01D5/35358 , G01D5/35361 , G01D5/35367 , G01D5/35387 , G01D5/3539 , G01D5/35393 , G01D5/35396
摘要： The application describes methods and apparatus for distributed fiber sensing, especially distributed acoustic/strain sensing. The method involves launching interrogating radiation in to an optical fiber and sampling radiation backscattered from within said fiber at a rate so as to acquire a plurality of samples corresponding to each sensing portion of interest. The plurality of samples are divided into separate processing channels and processed to determine a phase value for that channel. A quality metric is then applied to the processed phase data and the data combined to provide an overall phase value for the sensing portion based on the quality metric. The quality metric may be a measure of the degree of similarity of the processed data from the channels. The interrogating radiation may comprise two relatively narrow pulses separated by a relatively wide gap and the sampling rate may be set such that a plurality of substantially independent diversity samples are acquired.
摘要翻译： 该应用描述了用于分布式光纤感测的方法和装置，特别是分布式声/应变感测。 该方法包括将询问辐射发射到光纤中，并以一定速率从所述光纤内部向后散射的采样辐射采样，以便获得对应于感兴趣的感测部分的多个样本。 多个样本被分成单独的处理通道并被处理以确定该通道的相位值。 然后将质量度量应用于经处理的相位数据，并且组合的数据基于质量度量为感测部分提供总体相位值。 质量度量可以是来自信道的经处理数据的相似度的度量。 询问辐射可以包括由相对宽的间隙分开的两个相对窄的脉冲，并且可以设置采样率使得获得多个基本上独立的分集样本。
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公开(公告)号：US20120280117A1
公开(公告)日：2012-11-08
申请号：US13441802
申请日：2012-04-06
CPC分类号： G01H9/004 , G01D1/00 , G01D1/02 , G01D5/35303 , G01D5/35306 , G01D5/35312 , G01D5/35329 , G01D5/35345 , G01D5/35358 , G01D5/35361 , G01D5/35367 , G01D5/35387 , G01D5/3539 , G01D5/35393 , G01D5/35396
摘要： The application describes methods and apparatus for distributed fibre sensing, especially distributed acoustic/strain sensing. The method involves launching at least first and second pulse pairs into an optical fibre, the first and second pulse pairs having the same frequency configuration as one another and being generated such that the phase relationship of the pulses of the first pulse pair has a predetermined relative phase difference to the phase relationship of the pulses of the second pulse pair. In one embodiment there is a frequency difference between the pulses in a pulse pair which is related to the launch rate of the pulse pairs. In another embodiment the phase difference between the pulses in a pair is varied between successive launches. In this way an analytic version of the backscatter interference signal can be generated within the baseband of the sensor.
摘要翻译： 该应用描述了用于分布式光纤感测的方法和装置，特别是分布式声/应变感测。 该方法包括至少将第一和第二脉冲对发射到光纤中，第一和第二脉冲对具有彼此相同的频率配置并被产生，使得第一脉冲对的脉冲的相位关系具有预定的相对 相位差与第二脉冲对的脉冲的相位关系。 在一个实施例中，与脉冲对的发射速率相关的脉冲对中的脉冲之间存在频率差。 在另一个实施例中，一对脉冲之间的相位差在连续发射之间是变化的。 以这种方式，可以在传感器的基带内产生背散射干扰信号的分析版本。
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公开(公告)号：US20120278043A1
公开(公告)日：2012-11-01
申请号：US13441798
申请日：2012-04-06
IPC分类号： G01N21/49
CPC分类号： G01H9/004 , G01D1/00 , G01D1/02 , G01D5/35303 , G01D5/35306 , G01D5/35312 , G01D5/35329 , G01D5/35345 , G01D5/35358 , G01D5/35361 , G01D5/35367 , G01D5/35387 , G01D5/3539 , G01D5/35393 , G01D5/35396
摘要： The application describes methods and apparatus for distributed fibre sensing, especially distributed acoustic/strain sensing. The method involves launching interrogating radiation in to an optical fibre and sampling radiation backscattered from within said fibre at a rate so as to acquire a plurality of samples corresponding to each sensing portion of interest. The plurality of samples are divided into separate processing channels and processed to determine a phase value for that channel. A quality metric is then applied to the processed phase data and the data combined to provide an overall phase value for the sensing portion based on the quality metric. The quality metric may be a measure of the degree of similarity of the processed data from the channels. The interrogating radiation may comprise two relatively narrow pulses separated by a relatively wide gap and the sampling rate may be set such that a plurality of substantially independent diversity samples are acquired.
摘要翻译： 该应用描述了用于分布式光纤感测的方法和装置，特别是分布式声/应变感测。 该方法包括将询问辐射发射到光纤中，并以一定速率从所述光纤内部向后散射的采样辐射采样，以便获得对应于感兴趣的感测部分的多个样本。 多个样本被分成单独的处理通道并被处理以确定该通道的相位值。 然后将质量度量应用于经处理的相位数据，并且组合的数据基于质量度量为感测部分提供总体相位值。 质量度量可以是来自信道的经处理数据的相似度的度量。 询问辐射可以包括由相对宽的间隙分开的两个相对窄的脉冲，并且可以设置采样率使得获得多个基本上独立的分集样本。
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公开(公告)号：US06490045B1
公开(公告)日：2002-12-03
申请号：US09806963
申请日：2001-04-06
IPC分类号： G01B902
CPC分类号： G01D5/35322
摘要： A Sagnac or loop type interferometer is disclosed which uses a single broadband Erbium-doped fibre source (10) and a single IngaAs detector (150) together with a 40 km long sensor loop (90). A wavelength division multiplexer (50) spectrally slices the broadband light from the source (10) into two sub-bands, with different optical paths being defined between the source (10) and detector (150) for the light in the different spectrally sliced sub-bands. The two optical paths include separate phase modulators (70, 130) which modulate the two signals at different frequencies, and also separate delay loops (60, 130) at different places relative to the sensor loop (90). Effectively, two separate Sagnac loops are provided with a single sensor loop (90), source (10) and detector (150). Standard phase locked loop techniques can be used to extract information from signals that have passed through the two loops and to determine the location of a mechanical or thermal perturbation applied to the sensor loop (90).
摘要翻译： 公开了一种Sagnac或环型干涉仪，其使用单个宽带掺铒光纤源（10）和单个IngaAs检测器（150）以及40km长的传感器回路（90）。 波分多路复用器（50）将来自源（10）的宽带光光谱地切割成两个子带，其中在源（10）和检测器（150）之间限定不同光路，用于不同光谱切片子 带。 两个光路包括调制不同频率的两个信号的分离的相位调制器（70,130），以及在相对于传感器回路（90）的不同位置处分离的延迟环路（60,130）。 有效地，两个单独的Sagnac回路设置有单个传感器回路（90），源极（10）和检测器（150）。 标准锁相环技术可用于从已经通过两个环路的信号中提取信息，并确定施加到传感器回路（90）的机械或热扰动的位置。
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公开(公告)号：US06650798B2
公开(公告)日：2003-11-18
申请号：US10288431
申请日：2002-11-06
IPC分类号： G02B627
CPC分类号： G02B6/447
摘要： In order to identify a fiber optic cable (10) a beam (14) of polarised light is caused to pass down the cable to a first site (A) at which an electromagnetic field (24) is applied to the cable (10). The electromagnetic field (24) traverses the cable (10) in an essentially transverse direction and has a time-varying component orientated along the length of the cable (10) at the first site (A), with the component varying so that the line integral thereof along the cable (10) is non-zero. This results in a variation in the polarisation of the light, which can then be detected by a polarisation discriminator (20) at a second site (B), thereby to identify the cable (10).
摘要翻译： 为了识别光纤电缆（10），使得偏振光束（14）将电缆穿过第一位置（A），在第一位置（A）处将电磁场（24）施加到电缆（10）。 电磁场（24）在基本横向上横穿电缆（10），并且具有沿第一位置（A）处的电缆（10）的长度方向定向的时变分量，其中部件变化，使得线 沿着电缆（10）的整体不为零。 这导致光的偏振变化，其然后可以在第二位置（B）处由偏振鉴别器（20）检测，从而识别电缆（10）。
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