hello, i want to navigate P3AT (in USARSim @windows PC1) from ROS (Fuerte @UBUNTU PC2). i am using ros navigation stack for auto navigation. but facing an issue with rviz,

1. No transform from "[/base_GroundTruth]" to frame "[/map]" , click here to seen the problem snapshot

2. No transform from "[/GroundTruth]" to frame "[/map]"

question: how to get ride of this status warning.