Robust correlators

Context. Radio frequency interference (RFI) already limits the sensitivity of existing radio telescopes in several frequency bands and may prove to be an even greater obstacle for future generation instruments to overcome. Aims. I aim to create a structure of radio astronomy correlators which will be statistically stable (robust) in the presence of interference. Methods. A statistical analysis of the mixture of system noise + signal noise + RFI is proposed here which could be incorporated into the block diagram of a correlator. Order and rank statistics are especially useful when calculated in both temporal and frequency domains. Results. Several new algorithms of robust correlators are proposed and investigated here. Computer simulations and processing of real data demonstrate the efficacy of the proposed algorithms.