▁App lications ▁The ▁ult imate ▁goal ▁of ▁sensor ▁array ▁signal ▁processing ▁is ▁to ▁estimate ▁the ▁values ▁of ▁parameters ▁by ▁using ▁available ▁temporal ▁and ▁spatial ▁information , ▁collected ▁through ▁sampling ▁a ▁wave field ▁with ▁a ▁set ▁of ▁anten nas ▁that ▁have ▁a ▁precise ▁geometry ▁description . ▁The ▁processing ▁of ▁the ▁captured ▁data ▁and ▁information ▁is ▁done ▁under ▁the ▁assumption ▁that ▁the ▁wave field ▁is ▁generated ▁by ▁a ▁finite ▁number ▁of ▁signal ▁sources ▁( emit ters ), ▁and ▁contains ▁information ▁about ▁signal ▁parameters ▁character izing ▁and ▁describing ▁the ▁sources . ▁There ▁are ▁many ▁applications ▁related ▁to ▁the ▁above ▁problem ▁form ulation , ▁where ▁the ▁number ▁of ▁sources , ▁their ▁directions ▁and ▁locations ▁should ▁be ▁specified . ▁To ▁motiv ate ▁the ▁reader , ▁some ▁of ▁the ▁most ▁important ▁applications ▁related ▁to ▁array ▁processing ▁will ▁be ▁discussed . ▁▁ ▁Rad ar ▁and ▁Son ar ▁Systems : ▁array ▁processing ▁concept ▁was ▁closely ▁linked ▁to ▁rad ar ▁and ▁son ar ▁systems ▁which ▁represent ▁the ▁classical ▁applications ▁of ▁array ▁processing . ▁The ▁anten na ▁array ▁is ▁used ▁in ▁these ▁systems ▁to ▁determine ▁location ( s ) ▁of ▁source ( s ), ▁cancel ▁inter ference , ▁suppress ▁ground ▁cl utter . ▁Rad ar ▁systems ▁used ▁basically ▁to ▁detect ▁objects ▁by ▁using ▁radio ▁waves . ▁The ▁range , ▁alt itude , ▁speed ▁and ▁direction ▁of ▁objects ▁can ▁be ▁specified . ▁Rad ar ▁systems ▁started ▁as ▁military ▁equip ments ▁then ▁entered ▁the ▁civil ian ▁world . ▁In ▁rad ar ▁applications , ▁different ▁modes ▁can ▁be ▁used , ▁one ▁of ▁these ▁modes ▁is ▁the