ili ary ▁equipment ▁( field ▁AG ) ▁Ind ic ates ▁the ▁presence ▁of ▁a ▁to wed ▁son ar ▁array ▁( used ▁exclus ively ▁in ▁the ▁sea ▁surface ▁or ▁sub sur face ▁battle ▁dimensions ). ▁It ▁s its ▁below ▁the ▁frame , ▁like ▁field ▁R ▁( see ▁A ux ili ary ▁equipment , ▁below ). ▁Area ▁of ▁uncertainty ▁( field ▁A H ) ▁Ind ic ates ▁the ▁area ▁where ▁an ▁object ▁is ▁most ▁likely ▁to ▁be , ▁based ▁on ▁the ▁object ' s ▁last ▁report ▁and ▁the ▁reporting ▁accuracy ▁of ▁the ▁sensor ▁that ▁detected ▁it . ▁This ▁can ▁take ▁various ▁forms , ▁such ▁as ▁an ▁el lipse , ▁a ▁bound ing ▁box , ▁or ▁lines ▁indicating ▁probable ▁bearing ▁and ▁distance . ▁Dead ▁reck oning ▁tra iler ▁( field ▁A I ) ▁Ident ifies ▁where ▁an ▁object ▁should ▁be ▁located ▁at ▁present , ▁given ▁its ▁last ▁reported ▁course ▁and ▁speed . ▁This ▁can ▁take ▁the ▁form ▁of ▁a ▁d otted ▁line ▁( ext ending ▁from ▁the ▁symbol ▁to ▁the ▁dead - reck oned ▁position ) ▁or ▁a ▁d otted ▁circle ▁( bound ing ▁the ▁zone ▁the ▁object ▁may ▁have ▁reached ▁since , ▁when ▁the ▁direction ▁of ▁movement ▁is ▁unknown ▁or ▁uncertain ). ▁Speed ▁leader ▁( field ▁A J ) ▁Dep ict s ▁the ▁speed ▁and ▁direction ▁of ▁movement ▁of ▁an ▁object . ▁It ▁is ▁identical ▁to ▁the ▁D irection ▁of ▁Mov ement ▁indicator ▁except ▁that ▁its ▁length ▁is ▁variable ▁( and ▁there ▁is ▁no ▁arrow ▁head ). ▁P air ing ▁line ▁( field ▁A K