ERROR:SQLSTATE[HY000]: General error: 20018 Invalid column name 'CodigoInstitucion'. [20018] (severity 16) [SELECT PublicObrasAutores.NumeroEmpleado, PublicObrasAutores.ApellidoPaterno, PublicObrasAutores.ApellidoMaterno, PublicObrasAutores.Nombre, PublicObrasAutores.NombreCompleto FROM PublicObrasAutores LEFT JOIN PublicObrasAutoresFil ON PublicObrasAutores.RefPublicacion = PublicObrasAutoresFil.RefPublicacion WHERE PublicObrasAutores.RefPublicacion = '693988' AND PublicObrasAutores.NumeroEmpleado IS NULL AND PublicObrasAutoresFil.CodigoInstitucion IS NOT NULL;]
SELECT PublicObrasAutores.NumeroEmpleado, PublicObrasAutores.ApellidoPaterno, PublicObrasAutores.ApellidoMaterno, PublicObrasAutores.Nombre, PublicObrasAutores.NombreCompleto FROM PublicObrasAutores LEFT JOIN PublicObrasAutoresFil ON PublicObrasAutores.RefPublicacion = PublicObrasAutoresFil.RefPublicacion WHERE PublicObrasAutores.RefPublicacion = '693988' AND PublicObrasAutores.NumeroEmpleado IS NULL AND PublicObrasAutoresFil.CodigoInstitucion IS NOT NULL;

ERROR:SQLSTATE[HY000]: General error: 20018 Invalid column name 'CodigoInstitucion'. [20018] (severity 16) [SELECT PublicObrasAutores.NumeroEmpleado, PublicObrasAutores.ApellidoPaterno, PublicObrasAutores.ApellidoMaterno, PublicObrasAutores.Nombre, PublicObrasAutores.NombreCompleto FROM PublicObrasAutores LEFT JOIN PublicObrasAutoresFil ON PublicObrasAutores.RefPublicacion = PublicObrasAutoresFil.RefPublicacion WHERE PublicObrasAutores.RefPublicacion = '693988' AND PublicObrasAutores.NumeroEmpleado IS NULL AND PublicObrasAutoresFil.CodigoInstitucion IS NULL;]
SELECT PublicObrasAutores.NumeroEmpleado, PublicObrasAutores.ApellidoPaterno, PublicObrasAutores.ApellidoMaterno, PublicObrasAutores.Nombre, PublicObrasAutores.NombreCompleto FROM PublicObrasAutores LEFT JOIN PublicObrasAutoresFil ON PublicObrasAutores.RefPublicacion = PublicObrasAutoresFil.RefPublicacion WHERE PublicObrasAutores.RefPublicacion = '693988' AND PublicObrasAutores.NumeroEmpleado IS NULL AND PublicObrasAutoresFil.CodigoInstitucion IS NULL;

ERROR:SQLSTATE[HY000]: General error: 20018 Invalid column name 'Institucion'. [20018] (severity 16) [SELECT Institucion FROM PublicObrasAutoresFil WHERE RefPublicacion = '693988']
SELECT Institucion FROM PublicObrasAutoresFil WHERE RefPublicacion = '693988'

ERROR:SQLSTATE[HY000]: General error: 20018 Invalid column name 'Institucion'. [20018] (severity 16) [SELECT Institucion FROM PublicObrasAutoresFil WHERE RefPublicacion = 693988 AND InstitucionPropia = 'S' UNION SELECT Adscripciones.Entidad FROM PublicacionesObras JOIN PublicObrasAutores ON PublicacionesObras.Identificador = PublicObrasAutores.RefPublicacion JOIN Adscripciones ON PublicObrasAutores.NumeroEmpleado = Adscripciones.NumeroEmpleado WHERE (PublicacionesObras.FechaPublicacion BETWEEN Adscripciones.FechaDesde AND Adscripciones.FechaHasta OR (PublicacionesObras.FechaPublicacion >= Adscripciones.FechaDesde AND Adscripciones.FechaHasta IS NULL)) AND PublicacionesObras.Identificador= 693988]
SELECT Institucion FROM PublicObrasAutoresFil WHERE RefPublicacion = 693988 AND InstitucionPropia = 'S' UNION SELECT Adscripciones.Entidad FROM PublicacionesObras JOIN PublicObrasAutores ON PublicacionesObras.Identificador = PublicObrasAutores.RefPublicacion JOIN Adscripciones ON PublicObrasAutores.NumeroEmpleado = Adscripciones.NumeroEmpleado WHERE (PublicacionesObras.FechaPublicacion BETWEEN Adscripciones.FechaDesde AND Adscripciones.FechaHasta OR (PublicacionesObras.FechaPublicacion >= Adscripciones.FechaDesde AND Adscripciones.FechaHasta IS NULL)) AND PublicacionesObras.Identificador= 693988

Título del libro:
Título del capítulo: High accuracy localization of acoustic perturbation on a 60-km bidirectional coherent transmission system using a frequency-locked DFB laser

Autores UNAM:
RAMON GUTIERREZ CASTREJON;

---

Autores externos:

---

Idioma:

---

Año de publicación:
2025

---

Palabras clave:

Acoustic noise; Distributed feedback lasers; Fiber lasers; Fiber optic sensors; Gas dynamic lasers; High modulus textile fibers; Laser excitation; Laser mode locking; Light transmission; Photonics; Acoustic perturbations; Coherent detection; Coherent transmission systems; DFB-lasers; Fiber sensing; Instantaneous phase; Localisation; Narrow linewidth lasers; Perturbation localization; Transmitted light; Linewidth

---

Resumen:

Fiber sensing is attracting more and more research interest, and it brings new opportunities to the optical telecom network. Here, we employ a 60 km bidirectional coherent transmission system to realize distributed vibration sensing. A vibration, positioned at 20 km from the east and 40 km from the west terminals, induces length fluctuation of the fiber which transduces into phase fluctuations on the transmitted light. The instantaneous phase of the beating of the transmitted light and LO lasers is obtained in the digital domain. The position of the vibration is resolved by locating the peak in the cross-correlation of the measured instantaneous phase at both ends. Through comparison experiments of four narrow linewidth semiconductor lasers following a statistical approach, it is found that the localization accuracy strongly depends on the laser frequency noise level. We obtained the best localization accuracy using a DFB semiconductor laser electrically locked on an optical reference, both packaged in a common 14-pin butterfly. Its frequency noise is 35 Hz2/Hz at 2 kHz and it has a linewidth of 0.1 kHz. Employing this low-noise laser, we successfully detected an acoustic perturbation with a localization error of only 23 meters for a vibration at 2 kHz with a bandwidth of 400 Hz. In contrast, a free-running DFB laser and two external cavity lasers proved too noisy to obtain a localization error better than a few kilometers using the same excitation. © 2025 SPIE.

---

Entidades citadas de la UNAM:

---

Fuente:


ISBN:
9781510685086
Editorial:
SPIE

Tipo de producto:
Conference Paper

DOI:
10.1117/12.3041323