id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
223	Possible error in linearisation in ropp_pp_geometric_optics	Ian Culverwell	Ian Culverwell	"User João Francisco Galera Monico has uncovered a potential error in the linearisation of eqns 2.18-2.21, ROPP user guide III, in ropp_geometric_optics.f90.

He writes:

Hello Kristian...



I have been studying several topics realted with ROPP. In the subroutine ropp_pp_bending_angle_go, which call ropp_pp_geometric_optics, I found that maybe we have a problem.



In the linearization we have:



     A(1,1:3) = -v_leo/(c_light - DOT_PRODUCT(v_leo,U_leo))



but from my derivation it is



A(1,1:3) = -v_leo/(c_light - DOT_PRODUCT(v_gns,U_gns)).



Could you verify that?



Thank you



J F Galera Monico

 
I think he's right, but need to investigate further. 

"	defect	closed	normal	5.1	ropp_pp	4.1	fixed	Geom optics pre-processing, linearisation	Ian Culverwell