Search

Your search keyword '"SINGLE-STATION"' showing total 14 results
Start Over Descriptor "SINGLE-STATION"
14 results on '"SINGLE-STATION"'

1. Early Peak Ground Acceleration Prediction for On-Site Earthquake Early Warning Using LSTM Neural Network

Author

T.Y. Hsu and A. Pratomo

Subjects
PGA (peak ground acceleration), LSTM (long short-term memory networks), on-site earthquake early warning, single-station, Chi-Chi earthquake, Science
Abstract

On-site earthquake early warning techniques, which issue alerts based on seismic waves measured at a single station, are promising, and have performed quite successfully during some damaging earthquakes. Conventionally, most existing techniques extract several P-wave features from the first few seconds of seismic waves after the trigger to predict the intensity or destructiveness of an incoming earthquake. This type of technique neglects the behavior of temporal varying features within P waves. In other words, the characteristics of data sequences are not considered. In this study, a long short-term memory (LSTM) neural network, which is capable of learning order dependence in seismic waves, is employed to predict the peak ground acceleration (PGA) of the coming earthquake. A dense LSTM architecture is proposed and a large data set of earthquakes is used to train the LSTM model. The general performance of the LSTM model indicated that the predicted PGA values are quite promising but are generally overestimated. However, the predicted PGA of the Chi-Chi earthquake data set, whose fault rupture is complex and long, using the proposed LSTM model is more accurate than the PGA predicted in a previous study using a support vector regression approach. In addition, an alternative alert criterion, which issues alerts when the predicted PGA exceeds the threshold in successive time windows, is presented, and the performance of the proposed LSTM model when different PGA thresholds are considered is also discussed.

Published
2022
Full Text
View/download PDF

2. Locating surface deformation induced by earthquakes using GPS, GLONASS and Galileo ionospheric sounding from a single station.

Author

Zedek, Florian, Rolland, Lucie M., Mikesell, T. Dylan, Sladen, Anthony, Delouis, Bertrand, Twardzik, Cédric, and Coïsson, Pierdavide

Subjects
*INDUCED seismicity, *GLOBAL Positioning System, *IONOSPHERIC disturbances, *EARTHQUAKE prediction, *SEISMIC networks
Abstract

• One single GNSS station can locate the origin of a coseismic TEC perturbation. • A dual-frequency multi-GNSS station acts as an array of ionospheric receivers. • Increasing the number of GNSS satellites increases the precision of the localization. Monitoring earthquakes to rapidly forecast their consequences remains a challenging task, especially in areas far from seismic and geodetic networks. Large and shallow earthquakes induce disturbances in the ionospheric Total Electron Content (TEC). These disturbances are commonly detected using Global Navigation Satellite Systems (GNSS) stations that can sound the ionosphere at great distances. To address this instrumentation sparsity issue, we assess a single GNSS station's ability to constrain the origin location of a coseismic ionospheric disturbance (CID) using observations of TEC. We develop a grid-search method that explores different trial origins (i.e. source locations) to determine which synthetic CID signal best matches the observed TEC time series. We confirm that a larger number of monitoring satellites enhances the opportunity to have the favorable geometrical coverage of satellites needed to resolve CID origins. We use TEC data acquired during two earthquakes having different moment magnitudes: a Mw 7.1 from Turkey and a Mw 7.8 from New Zealand. Using a well-placed multi-GNSS station we are able to retrieve the CID origin with an accuracy of 50 km and a theoretical precision of the same order. We conclude that a very sparse network of multi-GNSS stations can provide an independent estimate of the spatial distribution of large scale coseismic motions, including offshore areas 200–300 km from the coastline. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

3. Structural total least squares algorithm for locating multiple disjoint sources based on AOA/TOA/FOA in the presence of system error.

Author

Chen, Xin, Wang, Ding, Liu, Rui-rui, Yin, Jie-xin, and Wu, Ying

Abstract

Single-station passive localization technology avoids the complex time synchronization and information exchange between multiple observatories, and is increasingly important in electronic warfare. Based on a single moving station localization system, a new method with high localization precision and numerical stability is proposed when the measurements from multiple disjoint sources are subject to the same station position and velocity displacement. According to the available measurements including the angle-of-arrival (AOA), time-of-arrival (TOA), and frequency-of-arrival (FOA), the corresponding pseudo linear equations are deduced. Based on this, a structural total least squares (STLS) optimization model is developed and the inverse iteration algorithm is used to obtain the stationary target location. The localization performance of the STLS localization algorithm is derived, and it is strictly proved that the theoretical performance of the STLS method is consistent with that of the constrained total least squares method under first-order error analysis, both of which can achieve the Cramér-Rao lower bound accuracy. Simulation results show the validity of the theoretical derivation and superiority of the new algorithm. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

4. Planetary Seismology using Single-Station and Small-Aperture Arrays: Implications for Mars and Ocean Worlds

Author

Marusiak, Angela Giuliano and Marusiak, Angela Giuliano

Abstract

Studying geophysical station deployment on Earth is essential preparation for future geophysical experiments elsewhere in the solar system. Here, I investigated how single-station seismometers and small-aperture seismic arrays in analog settings can quantify instrument capabilities, develop methodologies to detect and locate seismicity, and constrain internal structure. First, I used a single-station seismometer in Germany to study how the NASA InSight mission could constrain core depth. I showed that InSight could recover the Martian core within ±30 km if ≥ 3 events are located within an epicentral distance uncertainty of < ±1 degree. Increasing the number of detected events reduces core depth uncertainty, and higher signal-to-noise events will not affect core depth uncertainty or recovery rate. Next, I used environmental analogs in Earth's cryosphere to quantify how seismometer placement on a mock-lander would affect instrument performance and seismic science results for a future surface mission to an icy ocean world. If mock-lander instruments were unprotected from the wind, noise levels were 50 dB higher than those on the ground. However, once seismometers were shielded via burial, noise performances were similar to the ground-coupled seismometers, although spacecraft resonances were found at frequencies ~100 Hz. For icy ocean worlds lacking atmospheres, I showed that deck-mounted flight-candidate seismometers recorded ground motion comparably to surface-deployed instrumentation, with responses similar to terrestrial seismometers at frequencies > 0.1 Hz. Finally, I investigated seismicity detection capabilities of single-station and small-aperture seismic arrays. Small-aperture arrays were more effective at distinguishing low-frequency seismic events from noise and had fewer false positive events than a single-station. The Greenland site detected a higher percentage of teleseismic and regional tectonic events while the Gulkana Glacier, Alaska site observed more

Published
2020

5. A single-station multi-tasking 3D coordinate measurement method for large-scale metrology based on rotary-laser scanning.

Author

Zhexu Liu, Jigui Zhu, Linghui Yang, Haiqing Liu, Jun Wu, and Bin Xue

Subjects
METROLOGY, COORDINATES, OPTICAL scanners, ELECTRONIC probes, TRANSMITTERS (Communication)
Abstract

This paper presents a novel 3D coordinate measurement method based on the rotary-laser scanning technique for large-scale metrology. The method is implemented by a rotary-laser transmitter and a probe integrated with several photoelectric receivers. Measurement is accomplished with the tip of the probe contacting the measured point. The receivers capture the scanning angles of the laser planes emitted by the transmitter to calculate their corresponding equations. Then, we can establish the multi-plane constraint that the receiver points are in the corresponding planes. Subsequently, the coordinates of the measured point can be obtained through an optimization calculation method. In a 480 mm x 480 mm x 480 mm measurement volume that is 6 m away from the transmitter, the distance measurement accuracy of the proposed method is better than 0.40 mm and repeatability remains within 0.17 mm. For coordinate measurement, the accuracy and repeatability exceed 0.46 mm and 0.12 mm respectively. Experimental results show that the method is feasible and valid with good accuracy. [ABSTRACT FROM AUTHOR]

Published
2013
Full Text
View/download PDF

6. Preparing for InSight: Evaluation of the Blind Test for Martian Seismicity

Author

Swiss National Science Foundation, Centre National D'Etudes Spatiales (France), Swiss National Supercomputing Centre, Schimmel, Martin [0000-0003-2601-4462], van Driel, M., Ceylan, S., Clinton, John F., Giardini, Domenico, Alemany, H., Allam, A., Ambrois, David, Balestra, J., Banerdt, B., Becker, D., Böse, M., Boxberg, M. S., Brinkman, N., Casademont, T., Chèze, Jérôme, Daubar, I., Deschamps, Anne, Dethof, F., Ditz, M., Drilleau, M., Essing, D., Euchner, F., Fernando, B., García, Raphael, Garth, T., Godwin, H, Golombek, M. P., Grunert, Klaus G., Hadziioannou, C., Haindl, C., Hammer, C., Hochfeld, I., Hosseini, K., Hu, Hao, Kedar, S., Kenda, B., Khan, A., Kilchling, T., Knapmeyer‐Endrun, Brigitte, Lamert, A., Li, J. X., Lognonné, P., Mader, S., Marten, L., Mehrkens, F., Mercerat, D., Mimoun, D., Moller, T., Murdoch, N., Neumann, P., Neurath, R., Paffrath, M., Panning, M.P., Peix, F., Perrin, L., Rolland, L., Schimmel, Martin, Schroer, C., Spiga, A., Stahler, S. C., Steinmann, R., Stutzmann, E., Szenicer, A., Trumpik, N., Tsekhmistrenko, M., Twardzik, C., Weber, R., Werdenbach-Jarklowski, P., Zhang, S., Zheng, Y. C., Swiss National Science Foundation, Centre National D'Etudes Spatiales (France), Swiss National Supercomputing Centre, Schimmel, Martin [0000-0003-2601-4462], van Driel, M., Ceylan, S., Clinton, John F., Giardini, Domenico, Alemany, H., Allam, A., Ambrois, David, Balestra, J., Banerdt, B., Becker, D., Böse, M., Boxberg, M. S., Brinkman, N., Casademont, T., Chèze, Jérôme, Daubar, I., Deschamps, Anne, Dethof, F., Ditz, M., Drilleau, M., Essing, D., Euchner, F., Fernando, B., García, Raphael, Garth, T., Godwin, H, Golombek, M. P., Grunert, Klaus G., Hadziioannou, C., Haindl, C., Hammer, C., Hochfeld, I., Hosseini, K., Hu, Hao, Kedar, S., Kenda, B., Khan, A., Kilchling, T., Knapmeyer‐Endrun, Brigitte, Lamert, A., Li, J. X., Lognonné, P., Mader, S., Marten, L., Mehrkens, F., Mercerat, D., Mimoun, D., Moller, T., Murdoch, N., Neumann, P., Neurath, R., Paffrath, M., Panning, M.P., Peix, F., Perrin, L., Rolland, L., Schimmel, Martin, Schroer, C., Spiga, A., Stahler, S. C., Steinmann, R., Stutzmann, E., Szenicer, A., Trumpik, N., Tsekhmistrenko, M., Twardzik, C., Weber, R., Werdenbach-Jarklowski, P., Zhang, S., and Zheng, Y. C.

Abstract

In December 2018, the National Aeronautics and Space Administration (NASA) Interior exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission deployed a seismometer on the surface of Mars. In preparation for the data analysis, in July 2017, the marsquake service initiated a blind test in which participants were asked to detect and characterize seismicity embedded in a one Earth year long synthetic data set of continuous waveforms. Synthetic data were computed for a single station, mimicking the streams that will be available from InSight as well as the expected tectonic and impact seismicity, and noise conditions on Mars (Clinton et al., 2017). In total, 84 teams from 20 countries registered for the blind test and 11 of them submitted their results in early 2018. The collection of documentations, methods, ideas, and codes submitted by the participants exceeds 100 pages. The teams proposed well established as well as novel methods to tackle the challenging target of building a global seismicity catalog using a single station. This article summarizes the performance of the teams and highlights the most successful contributions.

Published
2019

7. SEIS: Insight’s Seismic Experiment for Internal Structure of Mars

Author

L. Perrin, C. Bonjour, N. Toulemont, Jean-Luc Berenguer, G. Perez, James Wookey, A. G. Mukherjee, Hallie Gengl, Edward A. Miller, Delphine Faye, Antoine Mocquet, J. Sicre, B. Vella, D. Dilhan, C. Larigauderie, John C. Bousman, M. Nonon, Y. Bennour, Véronique Dehant, Jeffrey W. Umland, T. Nebut, D. Hernandez, M. Eberhardt, Vincent Conejero, Rudolf Widmer-Schnidrig, Philippe Lognonné, G. de los Santos, S. A. D’Agostino, Savas Ceylan, Justin N. Maki, G. Aveni, P. Revuz, S. de Raucourt, C. Aicardi, Clément Perrin, A. K. Delahunty, Constanza Pardo, Domenico Giardini, L. Pou, Robert J. Calvet, D. Savoie, O. Robert, V. Gharakanian, S. Ben Charef, Constantinos Charalambous, Kerry Klein, S. M. Madzunkov, J. M. Desmarres, Sue Smrekar, S. B. Calcutt, F. Grinblat, Nicholas A Teanby, I. M. Standley, Naomi Murdoch, Brigitte Knapmeyer-Endrun, M. Deleuze, C. Doucet, William T. Pike, Tom L. Hoffman, F. Mialhe, Cecily M. Sunday, J. Paredes-Garcia, Matthew P. Golombek, P. Bhandari, Huafeng Liu, B. Pouilloux, E. Blanco, Gabriel Pont, Simon Stähler, M. E. Johnson, Nicolas Verdier, L. Luno, Ned W. Ferraro, R. Perez, Mélanie Drilleau, F. Ijpelaan, B. Lecomte, M. van Driel, A. Sauron, I. Estève, Mark P. Panning, David Mimoun, P. A. Dandonneau, B. Kenda, T. Gabsi, W. Raff, P. Boutte, T. Warren, Joan Ervin, Fabian Euchner, S. Tillier, K. J. Hurst, Stephen Larson, Davor Mance, Mark A. Wieczorek, J. A. Rodriguez-Manfredi, Justin Lin, Jaime Singer, M. Monecke, Robert W. Denise, E.-P. Miettinen, Maren Böse, E. Locatelli, I. Savin de Larclause, J. Gagnepain-Beyneix, L. Khachikyan, Philippe Laudet, T. Carlier, Alexander E. Stott, Neil Bowles, Brian Bone, C. Imbert, Sharon Kedar, A. Rosak, Fred Calef, O. Pot, O. M. Avalos, P. Labrot, Jeroen Tromp, Lucile Fayon, C. Moreau, J. Baroukh, William B. Banerdt, M. Bierwirth, Ranah Irshad, M. André, Christopher T. Russell, S. L. Marshall, M. Parise, J.-R. Meyer, P. Pasquier, N. Faye-Refalo, Ingrid Daubar, M. A. Balzer, R. Gonzalez, M. Hetzel, K. Brethomé, Y. Pahn, Raphaël F. Garcia, J. tenPierick, U. R. Christensen, Farah Alibay, Renee Weber, Robert G. Deen, Eléonore Stutzmann, J. Temple, Don Banfield, A. Bouisset, D. B. Klein, A. Borrien, Ashitey Trebi-Ollennu, R. Llorca-Cejudo, L. J. Facto, J. M. Mouret, Alexis Paillet, Peter Zweifel, P. Bruneau, Catherine L. Johnson, C. Brysbaert, J. E. Feldman, A. Kramer, Luigi Ferraioli, Jane Hurley, Taichi Kawamura, Nicholas Onufer, W. Kühne, Eric Beucler, Amir Khan, M. Sodki, L. Kerjean, A. Sylvestre-Baron, C. Desfoux, C. Yana, John Clinton, J. R. Willis, Juan Villalvazo, Pierre Delage, Mihail P. Petkov, M. C. Wallace, T. Camus, Ioannis G. Mikellides, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Institute of Geophysics [ETH Zürich], Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Mechanical Engineering [Imperial College London], Imperial College London, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Centre National d'Études Spatiales [Toulouse] (CNES), Geological Institute (ETHZ), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), University of Oxford, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), NASA Marshall Space Flight Center (MSFC), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire de Mecanique des Fluides et d'Acoustique (LMFA), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), Advanced Technology and Research, Space Science and Technology Department [Didcot] (RAL Space), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), Clarendon Laboratory [Oxford], Huazhong University of Science and Technology [Wuhan] (HUST), Kinemetrics, Cornell University [New York], Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), University of California [Los Angeles] (UCLA), University of California (UC), Institut of GeophysicsETHZ, Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Swiss Seismological Service, Royal Observatory of Belgium [Brussels] (ROB), Géotechnique (cermes), Laboratoire Navier (navier umr 8205), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of British Columbia (UBC), Planetary Science Institute [Tucson] (PSI), Laboratoire national de métrologie et d'essais - Systèmes de Référence Temps-Espace (LNE - SYRTE), Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), University of Bristol [Bristol], Department of Geosciences [Princeton], Princeton University, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Universität Stuttgart [Stuttgart], School of Earth Sciences [Bristol], Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), University of Oxford [Oxford], Max Planck Institute for Solar System Research (MPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of California, INSTITUT OF GEOPHYSICS ETHZ, Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Karlsruhe Institute of Technology and Stuttgart University, Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), California Institute of Technology (CALTECH)-NASA, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Département Electronique, Optronique et Signal (DEOS), Department of Earth Sciences [ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Cornell University, Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA), Royal Observatory of Belgium [Brussels], PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), School of Earth Sciences University of Bristol, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Seismometer, DISSIPATIVE FACTOR, 010504 meteorology & atmospheric sciences, FREE OSCILLATIONS, BULK COMPOSITION, Mars, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Astronomy & Astrophysics, 01 natural sciences, Transfer function, Article, NETWORK SCIENCE, Autre, 0103 physical sciences, 0201 Astronomical and Space Sciences, INTERIOR STRUCTURE, ddc:530, Ground segment, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, InSight, Data processing, Science & Technology, Physics, Bandwidth (signal processing), Mars seismology, Astronomy and Astrophysics, Moment magnitude scale, SINGLE-STATION, THERMAL EVOLUTION, Mars Exploration Program, Geodesy, Space and Planetary Science, Physical Sciences, WAVE PROPAGATION, ELYSIUM PLANITIA, [SDU.OTHER]Sciences of the Universe [physics]/Other, Robotic arm, SEIS, Geology, METEORITE IMPACTS
Abstract

By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars’ surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking’s Mars seismic monitoring by a factor of ∼2500 at 1 Hz and ∼200000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars’ surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of Mw∼3 at 40∘ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution., Space Science Reviews, 215 (1), ISSN:1572-9672, ISSN:0038-6308

Published
2019
Full Text
View/download PDF

8. Preparing for InSight: Evaluation of the Blind Test for Martian Seismicity

Author

Franziska Mehrkens, Lucie Rolland, Claudia Haindl, Christoph Schröer, Andre Lamert, Ingrid Daubar, Jiaxuan Li, Katharina Grunert, David Ambrois, Marc S. Boxberg, Thomas Möller, Paul Neumann, Harriet Godwin, Mélanie Drilleau, Raphaël F. Garcia, Sarah Mader, Martin van Driel, Mark P. Panning, Sharon Kedar, Titus Casademont, Matthew P. Golombek, Domenico Giardini, Amir Allam, Bruce Banerdt, Jérôme Chèze, Diego Mercerat, Simon Stähler, Dirk Becker, Lorenz Marten, Hector Alemany, John Clinton, Philippe Lognonné, Eléonore Stutzmann, Savas Ceylan, Balthasar Kenda, Isabell Hochfeld, Kasra Hosseini, Hao Hu, Fabrice Peix, David Essing, Fabian Dethof, T. Garth, Benjamin Fernando, Aymeric Spiga, Robert Neurath, Fabian Euchner, Shane Zhang, Tabea Kilchling, Julien Balestra, Nienke Brinkman, Marcel Paffrath, Brigitte Knapmeyer-Endrun, Martin Schimmel, Maren Böse, Yingcai Zheng, Manuel Ditz, Cedric Twardzik, Alexandre Szenicer, Céline Hadziioannou, Naomi Murdoch, Renee Weber, Anne Deschamps, David Mimoun, René Steinmann, Noah Trumpik, Philipp Werdenbach‐Jarklowski, Maria Tsekhmistrenko, Amir Khan, Conny Hammer, Ludovic Perrin, Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement - Equipe-projet MOUVGS (Cerema Equipe-projet MOUVGS), Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement (Cerema), INSIGHT, Swiss National Science Foundation, Centre National D'Etudes Spatiales (France), Swiss National Supercomputing Centre, Schimmel, Martin, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), and Schimmel, Martin [0000-0003-2601-4462]

Subjects
Seismometer, Outreach, 010504 meteorology & atmospheric sciences, Computer science, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Location, Polarization analysis, Mars, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Mission, Induced seismicity, 010502 geochemistry & geophysics, 01 natural sciences, 7. Clean energy, Synthetic data, Autre, Models, Single-station, Blind test, Seismology, 0105 earth and related environmental sciences, Quake (natural phenomenon), Martian, Fault zone, Inversion, Single station, Mars Exploration Program, Data science, Geophysics, 13. Climate action, [SDU]Sciences of the Universe [physics], Seismograms, Insight, Noise
Abstract

In December 2018, the National Aeronautics and Space Administration (NASA) Interior exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission deployed a seismometer on the surface of Mars. In preparation for the data analysis, in July 2017, the marsquake service initiated a blind test in which participants were asked to detect and characterize seismicity embedded in a one Earth year long synthetic data set of continuous waveforms. Synthetic data were computed for a single station, mimicking the streams that will be available from InSight as well as the expected tectonic and impact seismicity, and noise conditions on Mars (Clinton et al., 2017). In total, 84 teams from 20 countries registered for the blind test and 11 of them submitted their results in early 2018. The collection of documentations, methods, ideas, and codes submitted by the participants exceeds 100 pages. The teams proposed well established as well as novel methods to tackle the challenging target of building a global seismicity catalog using a single station. This article summarizes the performance of the teams and highlights the most successful contributions., This work was jointly funded by Swiss National Science Foundation and French Agence Nationale de la Recherche (SNF-ANR project 157133 "Seismology on Mars"); Swiss State Secretariat for Education, Research and Innovation (project "MarsQuake Service-Preparatory Phase"); and ETH Zurich (project "Preparatory phase for Mars InSight Ground Segment Support"). Additional support came from the Swiss National Supercomputing Centre (CSCS) under Project ID s682. Some of the research described in this article was supported by the Interior exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) project, Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA). The Houston team was partially funded by EAR-1621878. A. Spiga and L. Rolland acknowledge funding by Centre National d'Etudes Spatiales (CNES). This article constitutes InSight Contribution Number 93.

Published
2019
Full Text
View/download PDF

9. Magnitude Scales for Marsquakes

Author

Domenico Giardini, Maren Böse, Fabian Euchner, John Clinton, Amir Khan, Philippe Lognonné, Martin van Driel, Simon Stähler, Savas Ceylan, William B. Banerdt, Swiss Fed Inst Technol, Swiss Seismol Serv, Sonneggstr 5, CH-8092 Zurich, Switzerland, Swiss Fed Inst Technol, Inst Geophys, Sonneggstr 5, CH-8092 Zurich, Switzerland, Swiss Fed Inst Technol, Swiss Seismol Serv SED, Sonneggstr 5, CH-8092 Zurich, Switzerland, Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), CALTECH, Jet Prop Lab, M-S 321-B60,4800 Oak Grove Dr, Pasadena, CA 91109 USA, and Swiss National Science Foundation-Agence Nationale Recherche (SNF-ANR) 157133 Swiss National Supercomputing Center (CSCS) sm682

Subjects
010504 meteorology & atmospheric sciences, MODELS, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Magnitude (mathematics), BULK COMPOSITION, MARS SEISMICITY, 010502 geochemistry & geophysics, 01 natural sciences, NOISE, Background noise, Geochemistry and Petrology, EARTH, LOCATION, ENERGY-RELEASE, Seismogram, 0105 earth and related environmental sciences, SEISMOGRAMS, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Attenuation, SINGLE-STATION, Mars Exploration Program, INSIGHT MISSION, Geodesy, Geophysics, Amplitude, 13. Climate action, [SDU]Sciences of the Universe [physics], Seismic moment, Noise (radio), Geology
Abstract

International audience; In anticipation of the upcoming 2018 InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) Discovery mission to Mars, we calibrate magnitude scales for marsquakes that incorporate state-of-the-art knowledge on Mars interior structure and the expected ambient and instrumental noise. We regress magnitude determinations of 2600 randomly distributed marsquakes, simulated with a spectral element method for 13 published 1D structural models of Mars' interior. The continuous seismic data from InSight will be returned at 2 samples per second. To account for this limited bandwidth as well as for the expected noise conditions on Mars, we define and calibrate six magnitude scales: (1) local Mars magnitude M-L(Ma) at a period of 3 s for marsquakes at distances of up to 10 degrees; (2) P-wave magnitude m(b)(Ma); (3) S-wave magnitude m(bS)(Ma) each defined at a period of 3 s and calibrated for distances from 5 degrees to 100 degrees; (4) surface-wave magnitude M-s(Ma) defined at a period of 20 s, as well as (5) moment magnitudes M-FB(Ma); and (6) M-F(Ma) computed from the low-frequency (10-100 s) plateau of the displacement spectrum for either body waves or body and surface waves, respectively; we calibrate scales (4)-(6) for distances from 5 degrees to 180 degrees. We regress stable calibrations of the six scales with respect to the seismic moment magnitude at M-w 5.5 by correcting filtered phase amplitudes for attenuation with distance and source depth. Expected errors in epicentral distance and in source depth (25% and 20 km, respectively) translate into magnitude errors of 0.1-0.3 units. We validate our magnitude relations with an independent test dataset of 2600 synthetic marsquakes (1.0 15 degrees are expected to be hidden in the Mars background noise and will likely not be detectable.

Published
2018
Full Text
View/download PDF

10. On the Detectability and Use of Normal Modes for Determining Interior Structure of Mars

Author

Philippe Lognonné, Domenico Giardini, Simon Stähler, Mélanie Drilleau, Tamara Gudkova, Felix Bissig, V. N. Zharkov, Amir Khan, Ana-Catalina Plesa, Martin van Driel, William B. Banerdt, Mark P. Panning, Swiss Fed Inst Technol, Inst Geophys, Sonneggstr 5, CH-8092 Zurich, Switzerland, Institute of Geophysics [ETH Zürich], Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS), Bolshaya Gruzinskaya Str. 10-1, 123242 Moscow, Russia, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA, and Swiss National Science Foundation (SNSF) 200021_172508 Swiss National Supercomputing Centre (CSCS) s830

Subjects
Mars, Seismology, Normal modes, Interior structure, Inverse problems, 010504 meteorology & atmospheric sciences, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], BULK COMPOSITION, Geometry, WAVE-FORMS, 010502 geochemistry & geophysics, 01 natural sciences, Spectral line, Inverse problems KeyWords Plus:FREE OSCILLATIONS, Normal mode, Interior Structure, LUNAR INTERIOR, Range (statistics), EARTH, MARTIAN SEISMICITY, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, TORSIONAL OSCILLATIONS, Series (mathematics), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Autocorrelation, Astronomy and Astrophysics, SINGLE-STATION, Mars Exploration Program, INSIGHT MISSION, MANTLE MINERALS, Data set, Normal Modes, Space and Planetary Science, Surface wave, [SDU]Sciences of the Universe [physics], Author Keywords:Mars
Abstract

The InSight mission to Mars is well underway and will be the first mission to acquire seismic data from a planet other than Earth. In order to maximise the science return of the InSight data, a multifaceted approach will be needed that seeks to investigate the seismic data from a series of different frequency windows, including body waves, surface waves, and normal modes. Here, we present a methodology based on globally-averaged models that employs the long-period information encoded in the seismic data by looking for fundamental-mode spheroidal oscillations. From a preliminary analysis of the expected signal-to-noise ratio, we find that normal modes should be detectable during nighttime in the frequency range 5–15 mHz. For improved picking of (fundamental) normal modes, we show first that those are equally spaced between 5–15 mHz and then show how this spectral spacing, obtained through autocorrelation of the Fourier-transformed time series can be further employed to select normal mode peaks more consistently. Based on this set of normal-mode spectral frequencies, we proceed to show how this data set can be inverted for globally-averaged models of interior structure (to a depth of $\sim 250~\mbox{km}$ ), while simultaneously using the resultant synthetically-approximated normal mode peaks to verify the initial peak selection. This procedure can be applied iteratively to produce a “cleaned-up” set of spectral peaks that are ultimately inverted for a “final” interior-structure model. To investigate the effect of three-dimensional (3D) structure on normal mode spectra, we constructed a 3D model of Mars that includes variations in surface and Moho topography and lateral variations in mantle structure and employed this model to compute full 3D waveforms. The resultant time series are converted to spectra and the inter-station variation hereof is compared to the variation in spectra computed using different 1D models. The comparison shows that 3D effects are less significant than the variation incurred by the difference in radial models, which suggests that our 1D approach represents an adequate approximation of the global average structure of Mars.

Published
2018
Full Text
View/download PDF

11. A Machine‐Learning Approach for Earthquake Magnitude Estimation.

Author

Mousavi, S. Mostafa and Beroza, Gregory C.

Subjects
*MAGNITUDE estimation, *ARTIFICIAL neural networks, *SEISMOGRAMS, *RECURRENT neural networks, *EARTHQUAKE magnitude, *STANDARD deviations
Abstract

In this study, we present a fast and reliable method for end‐to‐end estimation of earthquake magnitude from raw waveforms recorded at single stations. We design a regressor (MagNet) composed of convolutional and recurrent neural networks that is not sensitive to the data normalization, hence waveform amplitude information can be utilized during the training. The network can learn distance‐dependent and site‐dependent functions directly from the training data. Our model can predict local magnitudes with an average error close to zero and standard deviation of ~0.2 based on single‐station waveforms without instrument response correction. We test the network for both local and duration magnitude scales and show a station‐based learning can be an effective approach for improving the performance. The proposed approach has a variety of potential applications from routine earthquake monitoring to early warning systems. Plain Language Summary: The size of an earthquake at its source is measured from the amplitude (or sometimes the duration) of the ground motion recorded on seismic instruments, and is expressed in terms of magnitude. Magnitude is a logarithmic measure and usually is measured based on data recorded by multiple stations after applying some pre‐proccessing and corrections to the raw signals. Here, we introduce the first successful deep‐learning approach to estimate directly the magnitude from raw seismic signals recorded on a single station. Key Points: A deep‐learning approach is presented for earthquake magnitude estimationNetwork consists of both convolutional and recurrent neural networksIt can estimate both ML and Md directly from raw seismograms recorded on a single station [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

12. Adjuvant therapy following induction therapy and surgery improves survival in N2-positive non-small cell lung cancer.

Author

White AA, Lee DN, Mazzola E, Kucukak S, Polhemus E, Jaklitsch MT, Mentzer SJ, Wee JO, Bueno R, and Swanson SJ

Subjects
Carcinoma, Non-Small-Cell Lung pathology, Carcinoma, Non-Small-Cell Lung therapy, Combined Modality Therapy, Female, Follow-Up Studies, Humans, Lung Neoplasms pathology, Lung Neoplasms therapy, Male, Middle Aged, Neoplasm Recurrence, Local pathology, Neoplasm Recurrence, Local therapy, Neoplasm Staging, Retrospective Studies, Survival Rate, Carcinoma, Non-Small-Cell Lung mortality, Induction Chemotherapy mortality, Lung Neoplasms mortality, Neoadjuvant Therapy mortality, Neoplasm Recurrence, Local mortality, Pneumonectomy mortality
Abstract

Background: The purpose of this study was to evaluate treatment strategies and factors influencing overall survival (OS) and disease-free survival (DFS) in resectable, non-small cell lung cancer (NSCLC) with mediastinal (N2) lymph node metastasis., Methods: All patients undergoing surgery for NSCLC with N2 disease between 2006 and 2016 were included. Treatment approaches included surgery only, neoadjuvant therapy followed by surgery, surgery followed by adjuvant therapy, and neoadjuvant therapy followed by surgery and adjuvant therapy (triple therapy). Patient clinical and pathologic data were retrospectively collected., Results: A total of 281 patients were included in the study. In total, 209 patients had neoadjuvant therapy, 47.4% of which went on to received additional adjuvant therapy. The pathologic complete response rate was 12.9%. The treatment strategy which included triple therapy was isolated as a significant contributor to improved OS and DFS. Nodal downstaging (N0) after induction therapy conferred an OS benefit (38.3% vs. 15.6%, p = .03). Patients with single-station N2 disease experienced higher DFS. Video-assisted thoracic surgery (VATS) lobectomy completion rates were higher at the end of the study period compared to the beginning (p < .001)., Conclusions: Patients who undergo neoadjuvant therapy for N2-positive NSCLC may benefit from additional adjuvant therapy. Single-station N2 disease confers higher DFS. VATS completion rates for lobectomy increase as experience increases., (© 2020 Wiley Periodicals LLC.)

Published
2021
Full Text
View/download PDF

14. Surgical outcomes after initial surgery for clinical single-station N2 non-small-cell lung cancer.

Author

Hishida T, Yoshida J, Ohe Y, Aokage K, Ishii G, and Nagai K

Subjects
Adult, Aged, Aged, 80 and over, Carcinoma, Non-Small-Cell Lung drug therapy, Carcinoma, Non-Small-Cell Lung pathology, Female, Follow-Up Studies, Humans, Lung Neoplasms drug therapy, Lung Neoplasms pathology, Lymphatic Metastasis, Male, Middle Aged, Neoplasm Staging, Positron-Emission Tomography, Prognosis, Retrospective Studies, Thoracotomy, Tomography, X-Ray Computed, Carcinoma, Non-Small-Cell Lung surgery, Lung Neoplasms surgery
Abstract

Objective: Single-station N2 (Stage IIIA) non-small-cell lung cancer has been reported to have a relatively favorable prognosis after surgery. However, most previous studies examined surgical outcomes in N2 disease by pathologic nodal status but not by clinical nodal status. The objective of this study was to clarify the surgical outcomes in clinical single-station N2 non-small-cell lung cancer patients., Methods: A total of 125 consecutive patients with clinical single-station N2 non-small-cell lung cancer were treated in our institution between 1992 and 2008. Among them, 97 (78%) patients underwent thoracotomy, and were included in this retrospective study. We defined clinical single-station N2 node as a node measuring 1-2 cm in a single mediastinal station observed on contrast-enhanced computed tomography. The median follow-up period was 5.9 years (range, 1.8-12.6)., Results: Eighty-eight (91%) patients underwent lung resection. Of them, 17 (19%) had true (pathologic) single-station N2 disease. Twenty-eight (32%) had pathologic multistation N2 and 43 (49%) had pN0-1 disease with favorable prognoses. The overall survival of the clinical single-station N2/pathologic N2 patients after initial surgery was unsatisfactory with a 5-year overall survival of 23.6%, but their prognoses were heterogeneous. True single-station pathologic N2 status (hazard ratio = 0.35, P = 0.008) and negative subcarinal node status (hazard ratio = 0.34, P = 0.022) were independent favorable prognostic factors after initial resection for clinical single-station N2/ pathologic N2 patients. The patients with both factors revealed a relatively favorable 5-year overall survival of 43.8%., Conclusion: Clinical single-station N2 status does not always correspond with pathologic true N2 status. From a prognostic point of view, initial surgery for clinical single-station N2 patients is indicated if their true single-station N2 status and negative subcarinal involvement are preoperatively confirmed.

Published
2014
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results