▁ 0 . 2 ▁and ▁F ▁would ▁be ▁ 1 . 2 5 . ▁The ▁observer ▁should ▁have ▁seen ▁ 2 5 % ▁more ▁met e ors , ▁therefore ▁multiply ▁by ▁F ▁= ▁ 1 . 2 5 . ▁ ▁This ▁represents ▁the ▁limit ing ▁magnitude ▁correction ▁factor ▁( Pop ulation ▁index ). ▁For ▁every ▁change ▁of ▁ 1 ▁magnitude ▁in ▁the ▁limit ing ▁magnitude ▁of ▁the ▁observer , ▁the ▁number ▁of ▁met e ors ▁observed ▁changes ▁by ▁a ▁factor ▁of ▁r . ▁Therefore , ▁this ▁must ▁be ▁taken ▁into ▁account . ▁ ▁Example : ▁If ▁r ▁is ▁ 2 , ▁and ▁the ▁observer ' s ▁limit ing ▁magnitude ▁is ▁ 5 . 5 , ▁the ▁hour ly ▁rate ▁is ▁multip lied ▁by ▁ 2 ▁( 2 ▁to ▁the ▁power ▁ 6 . 5 – 5 . 5 ), ▁to ▁know ▁how ▁many ▁met e ors ▁they ▁would ▁have ▁seen ▁if ▁their ▁limit ing ▁magnitude ▁was ▁ 6 . 5 . ▁ ▁This ▁represents ▁the ▁correction ▁factor ▁for ▁the ▁alt itude ▁of ▁the ▁radi ant ▁above ▁the ▁horizon ▁( h R ). ▁The ▁number ▁of ▁met e ors ▁seen ▁by ▁an ▁observer ▁changes ▁as ▁the ▁s ine ▁of ▁the ▁radi ant ▁height . ▁▁ ▁Example : ▁If ▁the ▁radi ant ▁was ▁at ▁an ▁average ▁alt itude ▁of ▁ 3 0 ° ▁during ▁the ▁observation ▁period , ▁the ▁observer ' s ▁hour ly ▁rate ▁will ▁need ▁to ▁be ▁divided ▁by ▁ 0 . 5 ▁( sin ▁ 3 0 ° ) ▁to ▁know ▁how