The radar has a long range of sight and was used in Desert Storm and in drug surveillance in the Gulf of Mexico. This is especially true about the user interface. The screens are large and graphical. The aircraft itself is a modified Boeing 707 with a radar dish mounted on top. This aircraft was developed in the 1960's and 70's to overcome limitations in conventional ground-based radar systems.
Radar works by sending out a radio signal which is reflected back by any airborne object.
The radar system listens for this reflection and by computing the time that the signal took to return, the information can be plotted on a monitor or computer screen. Unfortunately, ground based radar has some limitation. One major factor is the fact that the earth is round. One solution is to mount the radar transmitter and receiver higher. The higher you can get your radar dish, the farther you can see.