a method for target detection includes : receiving input data via an input signal ; generating a histogram from the received data by a processor ; rank - ordering the received data based on power or amplitude of the received input signal ; comparing the ranked data received in a current time period to the ranked data received in a previous time period to calculate a bivariate conditional exceedance function ; utilizing the calculated bcef to estimate a gumbel copula parameter ; accumulating a log - likelihood statistic from the estimated gumbel copula parameter and the generated histogram ; comparing the log - likelihood statistic with a threshold value ; and determining a detection of the target , when the log - likelihood statistic is below the threshold value .