The U.S. Air Force has updated the software for its E-8C Joint STARS (JSTARS) ground surveillance aircraft radar. The improved JSTARS radar can now spot and track UAVs and ultralight aircraft over water. This LSS (Low, Slow, Small) airborne targets upgrade also included a new receiver for the JSTARS, enabling the radar to get a good image of these small aircraft and make identification possible. This is one of several recent radar upgrades. Back in 2007, JSTARS software was upgraded so the radar could spot ships and small boats at sea and, in general, be useful to naval forces operating in crowded coastal waters (like the Persian Gulf). This upgrade took into account the wave movement, which had previously created a lot of false hits until new signal processing software was developed which, in effect, prevented moving water from messing up the JSTARS view of what was on the surface.
The E-8C aircraft are old and undergoing as many upgrades as the air force can afford. The air force has already determined that it will not be able to build a new model JSTARS aircraft (based on a smaller two engine jet like the Boeing 737). It is now believed that the next version of JSTARS will be a large UAV, like the Global Hawk, with all the human operators working from the ground.
The current plan is to upgrade and refurbish the existing JSTARS as much as possible, so they will last until about 2030. To that end, in 2010, the air force ordered replacement engines for two of its E-8Cs, at a cost of $112 million per aircraft. The new JT8D engines are modern designs similar to those used on commercial aircraft. The new engines will enable the E-8C to maintain the most effective altitude and burn less fuel doing it. The new engines also require less maintenance.
The air force is spending nearly $100 million on upgrading each of the 16 E-8Cs operated by reservists (the Air National Guard). The Internet type comms proved too expensive, so the JSTARS will have to get along with satellite data links it already has. Over the last three years the air force has tested or installed several upgrades for its 16 JSTARS aircraft. This included successfully testing a MS-177 very-high-resolution digital camera. The MS-177 enables the JSTARS to identify details of a vehicle its radar has spotted on the ground. The MS-177 is similar to a camera carried in U-2 reconnaissance aircraft since the 1990s. The MS-177 can distinguish a car from a van up to 80 kilometers away, while the JSTARS is at an altitude of 11,200 meters (35,000 feet). The MS-177 was linked to the JSTARS navigation system, thus providing precise location of whatever it saw and enabling targets to be confirmed in a minute or so, rather than waiting for an aircraft with a targeting pod to get close enough to clearly identify the target. Without the MS-177 the JSTARS radar merely indicates something down there is moving and what size it is. Despite the successful test, the air force was unable to equip more than one of the E-8Cs with the 591 kg (1,300 pound) camera. That's because the camera costs $15 million, and installing it in the aircraft costs another $4 million. Another alternative is to modify several E-8Cs to handle the MS-177, so that one or two of the cameras can be used on whatever aircraft are available.
The E-8 is a militarized Boeing 707. This is a 1950s design, also used for the KC-135 aerial tanker and other U.S. Air Force electronics warfare aircraft. The JSTARS ground search radar has two modes, wide area (showing a 25 by 20 kilometer area) and detailed (4,000 by 5,000 meters). The radar can see out to several hundred kilometers and each screen full of information could be saved and brought back later to compare to another view (to see what has moved). In this manner operators can track the movement of ground vehicles or ships. Operators can also use the detail mode to pick out specific details of what's going on down there, like tracking the movement of many small missile boats trying to rush an American warship. JSTARS can stay up there for over 12 hours at a time, and two or more JSTARS can operate in shifts to provide 24/7 coverage. JSTARS first proved its worth during the 1991 Gulf War, where it accurately, and in real time, tracked the movement of Coalition and Iraqi ground forces.