The sophisticated systems at large airports consist of two different radar systems , the `` primary '' and the `` secondary '' surveillance radar . The sophisticated systems at large airports consist of two different radar systems , the `` primary '' and `` secondary '' surveillance radar .
Sistem canggih di lapangan terbang besar terdiri daripada dua sistem radar yang berbeza, iaitu "primary" 'dan "secondary"'surveillance radar. Sistem canggih di lapangan terbang besar terdiri daripada dua sistem radar yang berbeza, iaitu "primary" 'dan "second"'surveillance radar.