C. Desoer, Electronics Letters, vol.6, issue.11, pp.339-340, 1970.
DOI : 10.1049/el:19700239

M. Freedman and G. Zames, Logarithmic Variation Criteria for the Stability of Systems with Time-Varying Gains, SIAM Journal on Control, vol.6, issue.3, pp.487-507, 1968.
DOI : 10.1137/0306031

L. Ljung, System Identification: Theory for the User, 1987.

A. H. Sayed, Fundamentals of Adaptive Filtering, 2003.

Y. Li, H. Wei, and S. A. Billings, Identification of Time-Varying Systems Using Multi-Wavelet Basis Functions, IEEE Transactions on Control Systems Technology, vol.19, issue.3, pp.656-663, 2011.
DOI : 10.1109/TCST.2010.2052257

R. Zou, H. Wang, and K. H. Chon, A Robust Time-Varying Identification Algorithm Using Basis Functions, Annals of Biomedical Engineering, vol.31, issue.7, pp.840-853, 2003.
DOI : 10.1114/1.1584683

Z. Qizhi and L. Li, Identification of Time-Varying System Based on Fourier Series, 2009 WRI Global Congress on Intelligent Systems, pp.44-47, 2009.
DOI : 10.1109/GCIS.2009.374

M. Niedzwiecki and T. Klaput, Fast recursive basis function estimators for identification of time-varying processes, IEEE Transactions on Signal Processing, vol.50, issue.8, pp.1925-1934, 2002.
DOI : 10.1109/TSP.2002.800390

M. Verhaegen and X. Yu, A class of subspace model identification algorithms to identify periodically and arbitrarily time-varying systems, Automatica, vol.31, issue.2, pp.201-216, 1995.
DOI : 10.1016/0005-1098(94)00091-V

K. Liu, IDENTIFICATION OF LINEAR TIME-VARYING SYSTEMS, Journal of Sound and Vibration, vol.206, issue.4, pp.487-505, 1997.
DOI : 10.1006/jsvi.1997.1105

K. Liu, EXTENSION OF MODAL ANALYSIS TO LINEAR TIME-VARYING SYSTEMS, Journal of Sound and Vibration, vol.226, issue.1, pp.149-167, 1999.
DOI : 10.1006/jsvi.1999.2286

K. Liu and L. Deng, Experimental verification of an algorithm for identification of linear time-varying systems, Journal of Sound and Vibration, vol.279, issue.3-5, pp.1170-1180, 2005.
DOI : 10.1016/j.jsv.2004.01.040

P. Van-overschee, B. De, and . Moor, Subspace Identification for Linear Systems: Theory, Implementation, Applications, 1996.
DOI : 10.1007/978-1-4613-0465-4

M. Majji, J. Juang, and J. L. Junkins, Time-Varying Eigensystem Realization Algorithm, Journal of Guidance, Control, and Dynamics, vol.41, issue.1, pp.13-28, 2010.
DOI : 10.1201/9780203509128.ch3

K. Josic and R. Rosenbaum, Unstable Solutions of Nonautonomous Linear Differential Equations, SIAM Review, vol.50, issue.3, pp.570-584, 2008.
DOI : 10.1137/060677057

É. Mathieu, Mémoire sur le mouvement vibratoire d'une membrane de forme elliptique, Journal de mathématiques pures et appliquées 2e série, pp.13-1868

G. Floquet, Sur les ??quations diff??rentielles lin??aires ?? coefficients p??riodiques, Annales scientifiques de l'??cole normale sup??rieure, vol.12, pp.47-88, 1883.
DOI : 10.24033/asens.220

J. A. Richards, Analysis of Periodically Time-varying Systems, 1983.
DOI : 10.1007/978-3-642-81873-8

P. Montagnier, C. C. Paige, and R. J. Spiteri, Real Floquet factors of linear time-periodic systems, Systems & Control Letters, vol.50, issue.4, pp.251-262, 2003.
DOI : 10.1016/S0167-6911(03)00158-0

S. Bittanti and P. Colaneri, Periodic Systems: Filtering and Control, 2009.

L. Sanches, G. Michon, A. Berlioz, and D. Alazard, Instability zones for isotropic and anisotropic multibladed rotor configurations, Mechanism and Machine Theory, pp.1054-1065, 2011.

L. Sanches, G. Michon, A. Berlioz, and D. Alazard, Parametrically excited helicopter ground resonance dynamics with high blade asymmetries, Journal of Sound and Vibration, vol.331, issue.16, pp.3897-3913, 2012.
DOI : 10.1016/j.jsv.2012.03.029

URL : https://hal.archives-ouvertes.fr/hal-00772189

C. C. Ross, Differential Equations: An Introduction with Mathematica s, 2004.
DOI : 10.1007/978-1-4757-3949-7

S. C. Sinha and E. Butcher, SYMBOLIC COMPUTATION OF FUNDAMENTAL SOLUTION MATRICES FOR LINEAR TIME-PERIODIC DYNAMICAL SYSTEMS, Journal of Sound and Vibration, vol.206, issue.1, pp.61-85, 1997.
DOI : 10.1006/jsvi.1997.1079

E. A. Butcher, H. Ma, E. Bueler, V. Averina, and Z. Szabo, Stability of linear time-periodic delay-differential equations via Chebyshev polynomials, International Journal for Numerical Methods in Engineering, vol.59, issue.7, pp.895-922, 2004.
DOI : 10.1002/nme.894

M. S. Allen, M. W. Sracic, S. Chauhan, and M. H. Hansen, Output-only modal analysis of linear time-periodic systems with application to wind turbine simulation data, Mechanical Systems and Signal Processing, vol.25, issue.4, pp.1174-1191, 2011.
DOI : 10.1016/j.ymssp.2010.12.018

M. Allen and J. H. Ginsberg, Floquet modal analysis to detect cracks in a rotating shaft on anisotropic supports, 24th International Modal Analysis Conference (IMAC XXIV), 2006.

M. Allen, Floquet Experimental Modal Analysis for System Identification of Linear Time-Periodic Systems, Volume 5: 6th International Conference on Multibody Systems, Nonlinear Dynamics, and Control, Parts A, B, and C, 2007.
DOI : 10.1115/DETC2007-34790

N. M. Wereley and S. R. Hall, Frequency response of linear time periodic systems, 29th IEEE Conference on Decision and Control, pp.3650-3655, 1990.
DOI : 10.1109/CDC.1990.203516

A. Benveniste and J. Fuchs, Single sample modal identification of a nonstationary stochastic process, IEEE Transactions on Automatic Control, vol.30, issue.1, pp.66-74, 1985.
DOI : 10.1109/TAC.1985.1103787

T. Soderstrom and P. Stoica, System Identification, International Series in Systems and Control Engineering, 1989.
DOI : 10.1115/1.2899207

B. Peeters and G. De-roeck, REFERENCE-BASED STOCHASTIC SUBSPACE IDENTIFICATION FOR OUTPUT-ONLY MODAL ANALYSIS, Mechanical Systems and Signal Processing, vol.13, issue.6, pp.855-878, 1999.
DOI : 10.1006/mssp.1999.1249

M. Basseville, A. Benveniste, M. Goursat, L. Hermans, and L. Mevel, Output-Only Subspace-Based Structural Identification: From Theory to Industrial Testing Practice, Journal of Dynamic Systems, Measurement, and Control, vol.34, issue.4, pp.668-676, 2001.
DOI : 10.1016/S0005-1098(98)00086-7

M. Goursat and L. , Algorithms for covariance subspace identification: a choice of effective implementations, Proceedings of the IMAC XXVII, 2009.
URL : https://hal.archives-ouvertes.fr/hal-00784554

M. Basseville, M. Abdelghani, and A. Benveniste, Subspace-based fault detection algorithms for vibration monitoring, Automatica, vol.36, issue.1, pp.101-109, 2000.
DOI : 10.1016/S0005-1098(99)00093-X

J. J. Dacunha and J. M. Davis, A unified Floquet theory for discrete, continuous, and hybrid periodic linear systems, Journal of Differential Equations, vol.251, issue.11, pp.2987-3027, 2011.
DOI : 10.1016/j.jde.2011.07.023

P. Skjoldan, Aeroelastic Modal Dynamics of Wind Turbines Including Anisotropic Effects, 2011.

R. Meyer and C. Burrus, A unified analysis of multirate and periodically time-varying digital filters, IEEE Transactions on Circuits and Systems, vol.22, issue.3, pp.162-168, 1975.
DOI : 10.1109/TCS.1975.1084020

A. Jhinaoui, L. Mevel, and J. Morlier, Subspace Identification for Linear Periodically Time-varying Systems*, Proceedings of the 16th IFAC Symposium on System Identification (SYSID), pp.1282-1287, 2012.
DOI : 10.3182/20120711-3-BE-2027.00148

URL : https://hal.archives-ouvertes.fr/hal-00695991

A. Jhinaoui, L. Mevel, and J. Morlier, Extension of subspace identification to lptv systems: application to helicopters, in: Topics in Modal Analysis I, pp.425-433, 2012.

L. Sanches, G. Michon, A. Berlioz, and D. Alazard, Instability zones identification in multiblade rotor dynamics, 11th Pan-American Congress of Applied Mechanics, 2010.

J. Wang and I. Chopra, Dynamics of helicopters in ground resonance with and without blade dissimilarities, Dynamics Specialists Conference, pp.273-291, 1992.
DOI : 10.2514/6.1991-192

G. Bir, Multi-Blade Coordinate Transformation and its Application to Wind Turbine Analysis, 46th AIAA Aerospace Sciences Meeting and Exhibit, 2008.
DOI : 10.1002/we.79

D. Tcherniak, S. Chauhan, M. Rossetti, I. Font, J. Basurko et al., Output-only modal analysis on operating wind turbines: application to simulated data, 2010.

K. Stol, H. Moll, G. Bir, and H. Namik, A Comparison of Multi-Blade Coordinate Transformation and Direct Periodic Techniques for Wind Turbine Control Design, 47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition, p.47, 2009.
DOI : 10.1115/1.3140706

L. Sanches, Helicopter Ground Resonance: Dynamical Modeling, Parametric Robustness Analysis and Experimental Validation, 2011.

M. Döhler, X. Lam, and L. , Uncertainty quantification for modal parameters from stochastic subspace identification on multi-setup measurements, Mechanical Systems and Signal Processing, vol.36, issue.2, pp.562-581, 2013.
DOI : 10.1016/j.ymssp.2012.11.011

D. L. Kunz, Influence of Elastomeric Damper Modeling on the Dynamic Response of Helicopter Rotors, AIAA Journal, vol.35, issue.2, pp.349-354, 1997.
DOI : 10.2514/6.1995-1449

D. L. Kunz, Nonlinear analysis of helicopter ground resonance, Nonlinear Analysis: Real World Applications, vol.3, issue.3, pp.383-395, 2002.
DOI : 10.1016/S1468-1218(01)00037-2

L. Pang, G. M. Kamath, and N. M. Wereley, Analysis and testing of a linear stroke magnetorheological damper, 39th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference and Exhibit, pp.2841-2856, 1998.
DOI : 10.1115/1.2823349

URL : http://www.enae.umd.edu/AGRC/faculty/Wereley/published/Abstracts/C1998aPangetal.pdf