Abstract This paper presents a method to estimate the covariances of the inputs in a factor-graph formulation for localization under non-line-of-sight conditions. A general solution based on covariance estimation and M-estimators in linear regression problems. is presented that is shown to give unbiased estimators of multiple variances and are robust against outliers. An iteratively r... https://www.eleanorscholz.com/product-category/egg-vibrators/