Systems and methods are disclosed to receive a plurality of samples of an ultrasound beam, each of the plurality of samples associated with a tissue depth, determine, for each of a plurality of candidate depths, a difference between the sum of each of the plurality of samples which is associated with a tissue depth from the candidate depth to a predetermined distance below the candidate depth, and the sum of each of the plurality of samples which is associated with a tissue depth from the candidate depth to the predetermined distance above the candidate depth, determine the largest determined difference, and determine the one of the plurality of candidate depths associated with the largest determined difference.
