True-amplitude imaging based on least-squares reverse time migration

Conventional reverse time migration (RTM) has disadvantages such as low frequency imaging, heavy noise, high requirements for acquisition, lack of compensating transmission losses and etc. In this paper, we propose a method for true-amplitude imaging based on least-squares reverse time migration. We treat the true-amplitude imaging as a linear inversion problem. Firstly, we derive the linearized wave propagation operator which is also called de-migration operator, and then we do some theoretical derivation on least-squares reverse time migration (LSRTM). Numerical tests on a multi-layer model and Marmousi model prove that LSRTM obtains true-amplitude imaging with higher imaging resolution than conventional reverse time migration, and the noise was also well suppressed.