Robust mean estimation for real-time blanking in radioastronomy
Résumé
Radio astronomy observations suffer from strong interferences that need to be blanked both in the time and frequency domains. In order to achieve real?time computations, interference detection is made by simple thresholding. The threshold value is linked to the mean estimation of the power of clean observed data that follows a chi2 distribution. Spurious values insensitivity is obtained by replacing mean by robust mean. A theoretical study of the variance of three estimators of the mean is presented. The study leads to a practical trimmed percentage that is chosen for the robust mean.