@techreport {louboutin2020SEGtwri,
	title = {Time-domain Wavefield Reconstruction Inversion in a TTI medium},
	number = {TR-CSE-2020-1},
	year = {2020},
	month = {4},
	institution = {Georgia Institute of Technology},
	abstract = {We introduce a generalization of time-domain wavefield reconstruction inversion to anisotropic acoustic modeling. Wavefield reconstruction inversion has been extensively researched in recent years for its ability to mitigate cycle skipping. The original method was formulated in the frequency domain with acoustic isotropic physics. However, frequency-domain modeling requires sophisticated iterative solvers that are difficult to scale to industrial-size problems and more realistic physical assumptions, such as tilted transverse isotropy, object of this study. The work presented here is based on a recently proposed dual formulation of wavefield reconstruction inversion, which allows time-domain propagator that are suitable to both large scales and more accurate physics.},
	keywords = {anisotropy, FWI, TTI, WRI},
	url = {https://slim.gatech.edu/Publications/Public/TechReport/2020/louboutin2020SEGtwri/louboutin2020SEGtwri.html},
	url2 = {https://arxiv.org/pdf/2004.07355.pdf},
	author = {Mathias Louboutin and Gabrio Rizzuti and Felix J. Herrmann}
}
@conference {louboutin2018SEGeow,
	title = {Effects of wrong adjoints for RTM in TTI media},
	booktitle = {SEG Technical Program Expanded Abstracts},
	year = {2018},
	note = {(SEG, Anaheim)},
	month = {10},
	pages = {331-335},
	abstract = {In order to obtain accurate images of the subsurface, anisotropic modeling and imaging is necessary. However, the twenty-one parameter complete wave-equation is too computationally expensive to be of use in this case. The transverse tilted isotropic wave-equation is then the next best feasible representation of the physics to use for imaging. The main complexity arising from transverse tilted isotropic imaging is to model the receiver wavefield (back propagation of the data or data residual) for the imaging condition. Unlike the isotropic or the full physics wave-equations, the transverse tilted isotropic wave-equation is not not self-adjoint. This difference means that time-reversal will not model the correct receiver wavefield and this can lead to incorrect subsurface images. In this work, we derive and implement the adjoint wave-equation to demonstrate the necessity of exact adjoint modeling for anisotropic modeling and compare our result with adjoint-free time-reversed imaging.},
	keywords = {Adjoint, anisotropy, finite-differences, Imaging, RTM, SEG, TTI},
	doi = {10.1190/segam2018-2996274.1},
	url = {https://slim.gatech.edu/Publications/Public/Conferences/SEG/2018/louboutin2018SEGeow/louboutin2018SEGeow.html},
	presentation = {https://slim.gatech.edu/Publications/Public/Conferences/SEG/2018/louboutin2018SEGeow/louboutin2018SEGeow_pres.pdf},
	author = {Mathias Louboutin and Philipp A. Witte and Felix J. Herrmann}
}
@techreport {witte2015TRoam,
	title = {Overview on anisotropic modeling and inversion},
	number = {TR-EOAS-2015-6},
	year = {2015},
	month = {08},
	institution = {UBC},
	abstract = {This note provides an overview on strategies for modeling and inversion with the anisotropic wave equation. Since linear and non-linear inversion methods like least squares RTM and Full Waveform Inversion depend on matching observed field data with synthetically modelled data, accounting for anisotropy effects is necessary in order to accurately match waveforms at long offsets and propagation times. In this note, the two main strategies for anisotropic modelling by solving either a pseudo acoustic wave equation or a pure quasi-P-wave equation are discussed and an inversion workflow using the pure quasi-P-wave equation is provided. In particular, we derive the exact adjoint of the anisotropic forward modelling and jacobian operator and give a detailled describtion of their implementation. The anistropic FWI workflow is tested on a sythetic data example.},
	keywords = {anisotropy, full waveform inversion, Modeling},
	url = {https://slim.gatech.edu/Publications/Public/TechReport/2015/witte2015TRoam/witte2015TRoam.html},
	author = {Philipp A. Witte and Mathias Louboutin and Felix J. Herrmann}
}
