Question about Polarization loss of RHC antenna

In page 17 and 18 of the article in the link:

http://www.antentop.org/009/files/tr009.pdf

There are two RHC antenna and the transmitting antenna is at the origin and the receiving antenna is in far field facing the origin. The link gave

But the article said the receiving antenna has it"s own coordinates

, and said the propagation direction from the transmitting antenna is in direction of

and

1) Is the change from -ve to +ve sign in the

due to the propagation direction of

referencing to the receiving antenna?