Calculated curves for groundwave propagation over inhomogeneous earth with pronounced topographical features

S~~';:~l numerical examples are prese nte d for radio propagation over a three s ec tio n pa th. These are base d on formulas whic h were d erive d ea rli e r [ Fu rut s u, 1957a[ Fu rut s u, , 1957b[ Fu rut s u, , 1959[ Fu rut s u, , 1963 ; ; Furutsu , Wilkerso n, and Hart m ann, 1964J in whic h the he ight a nd the e lec trical properties of eac h sec ti on may be d iffe ren t. F irs t the path is assumed to be a land-sea-Iand path an d a sea-lan d-sea path wi th no he ight difference; t he atten u atio n using this model is obtained bot h for the fl a t earth a nd the sp he ri ca l earth and the val ues are compa red to s how th e asy m ptoti c approach of these two value s at sho rt distances. Seco nd , the e ffec t of th e he ight a nd width of a mesa is illu s trated and th e att e nuat icn valu es a re co m pared to the va lu es obtained wh e n the obs tac le is a knife-e dge of the s ame he ight. Next th e effec t of vary ing the rece iv e r he ight is prese nte d wh en the pat h is eit he r a sea-land-sea path or a la nd-sea-la nd path . F inall y, examp les of th e atten ua ti on ca use d by both a c ha nne l and an is land having bluffs are given whi c h illu s trate t he recove ry effect as we ll as the diffract ion loss in th e vic inity of the coastlin es.