The report consists of notes that have been used in a course on search, detection, and localization modeling. In signal detection theory, the decision making portion of a detection system is called the receiver and a detection experiment is the observation by a receiver of input data accumulated during some time interval. The data that is related to a target is called signal. THe data that is not related to the target is called noise. In general, the target data is associated with a localization region that in some cases is called a resolution cell. Keywords: Search modeling; Detection modeling; Localization modeling. (JHD)