High Resolution Direct Detection and Position Determination of Sources With Intermittent Emission

This paper presents our research findings on the direct detection and position determination (DDPD) problem, which is to estimate the positions and the total number of multiple sources with intermittent emission, using the received signals intercepted by a moving antenna array at multiple observation slots. We combine the direct position determination (DPD) concept and the Minimum Variance Distortionless Response (MVDR) criterion to solve the DDPD problem without the prior knowledge of the effective number of sources (the number of sources at every observation slot). We find out that the parallel combination of the MVDR spectrum in the cost function results in its own sensitivity to the missing emission, which makes the location estimator bias. Therefore, we use the K-means clustering algorithm to identify the sources with intermittent emission and their emitting slots adaptively, based on the MVDR spectrum values over all observation slots. Then, we use the spectrum values of the identified emitting slots to reconstruct the MVDR spectrum. Finally, we find the peaks of the reconstructed MVDR spectrum, which are corresponding to the source positions. The results of the simulations demonstrate that the proposed method gets asymptotic performance with the signal to noise ratio (SNR), both in the aspects of the root mean square error (RMSE) and the bias error, and high resolution as a generalized MVDR based method.