also ▁known ▁as ▁all - we ather ▁f ighter ▁or ▁all - we ather ▁inter ceptor ▁for ▁a ▁period ▁of ▁time ▁after ▁World ▁War ▁II ) ▁is ▁a ▁f ighter ▁aircraft ▁adapted ▁for ▁use ▁at ▁night ▁or ▁in ▁other ▁times ▁of ▁bad ▁visibility . ▁Night ▁f igh ters ▁began ▁to ▁be ▁used ▁in ▁World ▁War ▁I ▁and ▁included ▁types ▁that ▁were ▁specifically ▁modified ▁to ▁operate ▁at ▁night . ▁ ▁During ▁World ▁War ▁II , ▁night ▁f igh ters ▁were ▁either ▁purpose - built ▁night ▁f ighter ▁designs , ▁or ▁more ▁commonly , ▁heavy ▁f igh ters ▁or ▁light ▁bom bers ▁adapted ▁for ▁the ▁mission , ▁often ▁employ ing ▁rad ar ▁or ▁other ▁systems ▁for ▁providing ▁some ▁sort ▁of ▁detection ▁cap ability ▁in ▁low ▁visibility . ▁Many ▁W W ▁II ▁night ▁f igh ters ▁also ▁included ▁instrument ▁landing ▁systems ▁for ▁landing ▁at ▁night , ▁as ▁turning ▁on ▁the ▁run way ▁lights ▁made ▁run ways ▁into ▁an ▁easy ▁target ▁for ▁oppos ing ▁intr ud ers . ▁Some ▁experiments ▁tested ▁the ▁use ▁of ▁day ▁f igh ters ▁on ▁night ▁miss ions , ▁but ▁these ▁t ended ▁to ▁work ▁only ▁under ▁very ▁favor able ▁circumstances ▁and ▁were ▁not ▁widely ▁successful . ▁ ▁Av ion ics ▁systems ▁were ▁greatly ▁mini atur ized ▁over ▁time , ▁allowing ▁the ▁addition ▁of ▁rad ar ▁alt imeter , ▁terrain - follow ing ▁rad ar , ▁improved ▁instrument ▁landing ▁system , ▁mic row ave ▁landing ▁system , ▁Do pp ler ▁weather ▁rad ar , ▁L OR AN ▁rece ivers , ▁G EE ,