IEEE 802.15.4 range measurements

In the master’s thesis IEEE 802.15.4 Range measurements I want to find out, whether atmospheric conditions have influence over the quality of communication between two ZigBee modules. I would like found the answer by long-time test, because I can’t found the proper place for the measuring, I must found the answer in the literature. In the second part of the master’s thesis I measuring, whether placing one of the module in the car have influence over the quality of communication. The module was placing in the various places in the car, on a dashboard, on a guest-passenger’s seat, in a pocket before guest-passenger and in luggage compartment. The car for the measuring was used Renaul Scénic my. 2004