I don't think the AMDAR plot is working yet. But AMDAR is similar to ACARS (Aircraft Communication and Reporting System) It allows you to obtain weather reports from airborne aircraft, decode their message and produce a graphical output.
I do not think Tim has got it working as yet in this release. However I have placed a question about this in this forum, take a look at the Digital Atmosphere Testing Laboratory Index and look for a topic whihc mentions ACARS and AMDAR in the title.
