Classical space-time adaptive processing (STAP) detectors are strongly limited when facing highly heterogeneous environments. Indeed, in this case, representative target free data are no longer available. Single dataset algorithms, such as the MLED algorithm, have proved their efficiency in overcoming this problem by only working on primary data.These methods are based on the APES algorithm which removes the useful signal from the covariance matrix. However, a small part of the clutter signal is also removed from the covariancematrix in this operation. Consequently, a degradation of clutter rejection performance is observed.We propose two algorithms that use deterministic aided STAP to overcome this issue of the single dataset APESmethod. The results on realistic simulated data and real data show that these methods outperform traditional single dataset methods in detection and in clutter rejection.