Systems and methods for determining ranges to a target disposed behind a transparent surface are described. A target acquisition system receives a plurality of lidar returns, at least some of which are from a target and at least some of which are from a transparent surface. The lidar returns correspond to a portion of a lidar signal generated by a lidar, directed toward the target, and reflected back to the lidar from either the target or the transparent surface. A range measurement for each of the plurality of lidar returns is determined. The target acquisition system generates a histogram of the range measurements. The histogram includes an array including a plurality of range bins. Each range bin defines a unique portion of a predetermined distance out from the lidar. The histogram further includes a count associated with each respective range bin. The count corresponds to a number of range measurements falling within the unique portion of the predetermined distance corresponding to that respective range bin. In some implementations of the invention, the target acquisition system determines which of the range measurements correspond to the target based on the histogram. In some implementations of the invention, the target acquisition system determines which of the range measurements correspond to the transparent surface based on the histogram.