A wireless communication device performs DC removal on a received signal using a coarse DC removal unit that removes relatively large DC components and a fine DC removal loop that removes residual DC components. According to various embodiments, a surface mounting system comprises a support assembly which mates with one or more collars positioned above and below the surface to which the mounting system is secured. The frequency of radar signals from the transmitter is adjusted according to a velocity of the aircraft calculated using the error in ground speed estimate or using the error in ground speed estimate. A number of entities are sampled from the named entity candidates. The protruding portion of the sample protrudes above the mount and is grinded by the grinder.