It's a loaded question since we don't have all the details yet. We all know that, and short of a video of someone making the map the radical skeptics can always claim we're just mindless FBI apologists (or something). However, and it was Hominid who first came up with this, we can tell a lot about the map just by giving it a close examination. The map has red markings corresponding to exact lat/long positions. The marks are perfectly perpendicular, meaning the markings were done on a set up like a drafting table with a square and triangle. Likely, this marks were made from a single source, most likely a readout of the radar data. The map has a military GEOREF connotation on it, suggesting it was made by someone familiar with the system. We have documentation that the map came from the military, so this fits. The heavy grease pen (or felt tip pen, I can't tell) was made by someone else much later. Probably the FBI since they would be concerned with a continuous flight path. There, not difficult. The map is significant and likely tells us the actual radar data from the night of the skyjacking.
