program lin

	implicit none

	integer choice	
	real a,r5,b
	real g,theta,atheta
	
 1	write(*,*)'Rain rate (mm/hr)- avg over 5 minutes?'
	read(*,*)r5
	write(*,*)'a,b coeffs?'
	read(*,*)a,b
	write(*,*)'elevation angle (Deg)?'
	read(*,*)theta
 2	write(*,*)'Ground terminal ht above sea level (Km)?'
	read(*,*)g
	
 10	atheta=a*r5**b*2636/(r5-6.2+2636*sind(theta)/(4-G))
	write(*,*)'Attenuation:',atheta
	
	write(*,*)'0=quit, 1=change rain rate 2=change a,b'
	write(*,*)'3=change theta, 4=change g 5=change all'
	read(*,*)choice
	if (choice.eq.5) goto 1
	if (choice.eq.4) goto 2
	if (choice.eq.3) then 
	  write(*,*)'elevation angle (Deg)?'
	  read(*,*)theta 
	  goto 10
	endif
	if (choice.eq.2) then
	  write(*,*)'a,b coeffs?'
	  read(*,*)a,b
	  goto 10
	endif
	if (choice.eq.1) then
 	  write(*,*)'Rain rate (mm/hr)- avg over 5 minutes?'
	  read(*,*)r5
	  goto 10
	endif
	end