21. One is where the radar has bounced microwave energy off the skin of a plane and recorded an echo, called primary radar . 22. As in all primary radar systems, the radiation reflected off a target is analyzed to produce a radar map on a screen. 23. "Controllers at NEADS located an unknown primary radar track [ Flight 77 ], but " it kind of faded " over Washington. 24. The lack of any authentication within the standard makes it mandatory to validate any received data by use of the primary radar . 25. ""'Controllers at NEADS located an unknown primary radar track "'[ Flight 77 ], but " it kind of faded " over Washington. 26. The bearing derived from the main primary radar would enable a reading of the height to be sent back to the operator. 27. In Olathe, FAA officials said they took the primary radar display system down for maintenance every Saturday night, a relatively slow period. 28. These primary radar hits might be indicative-- and I emphasize might be indicative-- of something coming off Flight 261 near this point, 29. In the late nineties, the installation became remote operation, and the primary Radar was replaced with the British Aerospace ( BAe ) Type 101. 30. These primary radar hits might be indicative _ and I emphasize might be indicative _ of something coming off Flight 261 near this point,
