Polarization based direction of arrival estimation using a radio interferometric array
This enables early DOA estimation for transient sources and radio frequency interference in radio astronomy, but it is an incremental improvement as it adapts existing arrays rather than introducing a new paradigm.
The paper tackles the problem of direction of arrival (DOA) estimation using radio interferometric arrays, which are typically not designed for this purpose, by proposing a low-cost method that uses a subset of the array and data to enable early DOA determination without imaging.
Direction of arrival (DOA) estimation is mostly performed using specialized arrays that have carefully designed receiver spacing and layouts to match the operating frequency range. In contrast, radio interferometric arrays are designed to optimally sample the Fourier space data for making high quality images of the sky. Therefore, using existing radio interferometric arrays (with arbitrary geometry and wide frequency variation) for DOA estimation is practically infeasible except by using images made by such interferometers. In this paper, we focus on low cost DOA estimation without imaging, using a subset of a radio interferometric array, using a fraction of the data collected by the full array, and, enabling early determination of DOAs. The proposed method is suitable for transient and low duty cycle source detection. Moreover, the proposed method is an ideal follow-up step to online radio frequency interference (RFI) mitigation, enabling the early estimation of the DOA of the detected RFI.