The Joint Surveillance Target Attack Radar System (Joint STARS) is a long-range, air-to-ground surveillance system designed to locate, classify and track ground targets in all weather conditions. While flying in friendly airspace, the joint Army-Air Force program can look deep behind hostile borders to detect and track ground movements in both forward and rear areas. It has a range of more than 150 miles (250 km). These capabilities make Joint STARS effective for dealing with any contingency, whether actual or impending military aggression, international treaty verification, or border violation.

The program was initially known as JSTARS, and subsequently designated Joint STARS. With the transition of the system to operational status with Air Combat Command, systems names currently under consideration include Sentinel II [aircraft previously named Sentinel include the World War II vintage Army Air Forces Stinson L5 and the Marine Corps Convair OY-1 and OY-2 light observation aircraft, and the unbuilt Lockheed P-3 airborne early warning and control aircraft proposal of 1984], Excalibur [a name once considered for the B-1B Lancer], and Night Owl.

Joint STARS consists of an airborne platform--an E-8C aircraft with a multi-mode radar system--and U.S. Army mobile Ground Station Modules (GSMs).

The E-8C, a modified Boeing 707, carries a phased-array radar antenna in a 26-foot canoe-shaped radome under the forward part of the fuselage. The radar is capable of providing targeting and battle management data to all Joint STARS operators, both in the aircraft and in the ground station modules. These operators, in turn, can call on aircraft, missiles or artillery for fire support. With a reported range in excess of 155 miles, this radar can cover an estimated 386,100 square miles in a single eight-hour sortie.

Wide Area Surveillance and Moving Target Indicator (WAS/MTI) are the radar's fundamental operating modes. WAS/MTI is designed to detect, locate and identify slow-moving targets. Through advanced signal processing, Joint STARS can differentiate between wheeled and tracked vehicles. By focusing on smaller terrain areas, the radar image can be enhanced for increased resolution display. This high resolution is used to define moving targets and provide combat units with accurate information for attack planning.

Synthetic Aperture Radar/Fixed Target Indicator (SAR/FTI) produces a photographic-like image or map of selected geographic regions. SAR data maps contain precise locations of critical non-moving targets such as bridges, harbors, airports, buildings, or stopped vehicles.

The FTI display is available while operating in the SAR mode to identify and locate fixed targets within the SAR area. The SAR and FTI capability used in conjunction with MTI and MTI history display allows post-attack assessments to be made by onboard or ground operators following a weapon attack on hostile targets.

Joint STARS operates in virtually any weather, on-line, in real-time, around the clock. The augmented Army-Air Force mission crew can be deployed to a potential trouble spot within hours and provide valuable data on ground force movements.

Major advanced technological elements of the program include the software-intensive radar with several operating modes; the unique antenna with three receive ports; four high-speed processors capable of performing more than 600 million operations per second; and the associated software.

JSTARS, supported by maritime patrol aircraft from Patrol Reconnaissance Force, SEVENTH Fleet, helped to fill in the tactical picture ashore for the Navy-Marine Corps team during Combined Exercise Foal Eagle `97 in Korea. For FE97, a JSTARS ground station was temporarily installed for evaluation in the Supporting Arms Coordination Center (SACC) aboard USS Belleau Wood (LHA-3). With its ability to scan an area over 20,000 square kilometers for any and all signs of movement, JSTARS gave the embarked amphibious warfare commanders a remarkably accurate tactical picture of what was happening in the exercise area. JSTARS flew several missions during Foal Eagle 97 from a safe standoff distance of up to 250 kilometers. Using the "tipper" indications provided by JSTARS, the U.S. Navy P-3 aircraft, using prototype imagery transfer capabilities, could then provide a "soda straw" close-up optical view of any desired area using its high resolution video camera. The P-3's video output was downlinked to the ship and fed into a TV system that displayed the picture at key command locations, including the SACC.


Production Plans
There has been considerable variation in the total number of aircraft planned during the course of the program's history.

In April 1988 the Defense Acquisition Board increased the number of planned production aircraft from 10 to 22 [with some Air Force planners arguing at the time for as many as 35 production aircraft].
On 19 September 1990 the DOD Joint Requirements Oversight Council [JROC] reduced the total inventory requirement from 22 to 20 JSTARS production aircraft, in addition to the three pre-production aircraft. Of the 20 E-8s, 17 were classified as Primary Aircraft Authorization (PAA), 2 as Backup Aircraft Inventory (BAI), and 1 as a test aircraft.
On 25 September 1996 the Under Secretary of Defense for Acquisition approved Joint STARS full-rate production with a total planned quantity of 19 production aircraft.
As of 1996 the Air Force planned that by 2004 the Joint STARS program would include a 19-plane fleet outfitted with advanced technology in radar and computer data systems.
The May 1997 Quadrennial Defense Review directed that the planned buy of 19 production aircraft be reduced to 13 -- 10 PAA, 2 BAI, and 1 Test for a total of 13, contingent on NATO buying 6 Joint STARS aircraft.
JSTARS aircraft deployments require four aircraft to maintain one continuous orbit. Planners initially believed that 3 continuous orbits would cover the theater of a Major Theater War. But experience in Bosnia's mountainous terrain suggests even smaller operation might require more than three continuously orbiting aircraft. Other assessments suggest that more than 30 JSTARS might be needed to meet existing two Major Theater War requirements, assuming that six orbits were required, with five aircraft needed to maintain a single orbit.

Improvements and Upgrades
The Radar Technology Insertion Program (RTIP) is a Pre Planned Product Improvement (P3I) effort where the contractor will be required to design, develop, install, test, and integrate advanced radar systems in the Joint STARS system. An option for a cooperative development of common radar technology with the United Kingdom, including risk reduction prototyping, ground and flight testing is possible. The RTIP Engineering Manufacturing Development (EMD) program will design, integrate and test an advanced RTIP sensor subsystem for the E-8C, sufficient to enable a production decision, and transition into a production, retrofit program. The program will explore wide band data link and anti-tamper security considerations. The E-8C Joint STARS System baseline resulting from the Computer Replacement Program and TADIL-J Upgrade baseline merge effort, under Contract F19628-90-C-0197, will be the starting baseline. On 30 November 1998 Northrop Grumman Corporation's Electronic Sensors and Systems Sector (ES3) and Raytheon Systems Company announced an agreement calling for an equal "50-50" work share on the radar sensor portion of RTIP. The Northrop Grumman Integrated Systems and Aerostructures (ISA) Sector will continue as the RTIP prime contractor with Raytheon as a subcontractor to Northrop Grumman ES3. Northrop Grumman's Integrated Systems and Aerostructures Sector, which is the RTIP prime contractor, will design, develop, install, test and integrate advanced radar systems into Joint STARS at its Airborne Surveillance and Battle Management Systems unit in Melbourne, FL. The Improved Data Modem (IDM) connected to four radios and the concurrent installation of a SINCGARS radio with the IDM and an additional SINCGARS hot spare provides an interoperable, full duplex, direct targeting support data link to the US Army’s Army Aviation Command and Control System (A2C2S) and Apache attack helicopters. This installation will be accessible from any E-8 Operator Work Station (OWS), will be fully logistically supportable and includes associated C2 and attack support messages. Joint STARS E-8 does not have the capability to provide direct data-link targeting information to A2C2S and Apaches. The E-8 communications suite does not have fully compatible and interoperable VHF voice and data capable radios with US Army aviation and ground forces. This capability emulates the initiative to provide Joint STARS data to fighter aircraft. This vastly improves targeting support primarily to Army aviation by providing a fully interoperable data link to C2 and attack helicopters. This capability will also increase Army Joint STARS Common Ground Station (CGS) communications capabilities through the E-8 to Army aviation when helicopters are Beyond-Line-Of-Sight (BLOS) of the CGS. This also has potential to support USMC aviation and USAF IDM equipped fighters and to decrease fratricide. The IDM can also pass Apache sensor information back to the E-8, increasing situational awareness and improving target correlation capability.
The JT3D-7 Engine Upgrade modification will allow the E-8 to operate between FL340 to FL 420 with a climb to altitude within one hour. It will increase the capablity of flying a ten hour sortie without air refueling (two our transit time, eight hours in tactical orbit). It will also increase the capablity of flying a 20 hour sortie with an air refueling (two hours transit time, one hour for air refueling, 17 hours in the tactical orbit). Low engine thrust limits deployment of Joint STARS to only those airfields with long runways. The E-8 can operate at maximum gross weight on only the longest runways (10,000 ft) under optimum weather conditions. Any crosswind, gust, or wet runway conditions severely limits takeoff gross weight. Low thrust engines limit capability to meet required operating altitudes between FL340 and FL420. At heavy gross weights the E-8 cannot meet climb and on station requirements. Higher thrust engines will provide faster climb to higher operational altitude. This improvement increases sensor coverage, on orbit time, communications reach, survivability, and decreases sensor screening. E-8 engines are being purchased from available commercial stocks which include many JT3D-7 engines. The JT3D-7 engines will have to be down scoped to match the existing JT3D-3B engines if this upgrade is not funded. The total requirement of 80 operational engines plus spares is not reflected in the schedule and cost because some JT3D-7 engines have already been purhcased but not yet down scoped.

The Programmable Signal Processor (PSP) Replacement replaces four PSPs with two Commercial-Off-The-Shelf (COTS) processors with five additional SHARC processor cards for a total of eight. The solution replaces the four PSPs with two COTS processors with five additional SHARC processor cards, replaces the existing PSP/GPC LAN with a fiber ring, redesigns the PSP code from microcode to HOL, redesigns the PSP rack configuration from a four rack to a two rack design to include installation, power, cooling, and cabling and improved diagnostics and Shop Replaceable Unit (SRU) maintainability. The aircraft currently uses four PSPs which work at maximum processing capacity providing adequate mission support. The E-8 has little growth capability for increased processing required for sensor upgrades. Current processors incorporate inefficient sensor idle time when processing Synthetic Aperture Radar (SAR). The current PSPs also have a high potential for becoming a Diminishing Manufacturing Source (DMS). Currently there is no sensor or processing growth potential and no open architecture capability. This upgrade provides improved radar timeline by eliminating the sensor idle time. It is required to provide growth processing and memory capacity for sensor upgrades (ESAR, ISAR, ATR). It improves supportability of both hardware and software components of the PSPs, and provides an open architecture base and limited weight and space reductions.

The Enhanced Synthetic Aperture Radar (SAR) and Inverse Synthetic Aperture Radar (SAR) upgrades allow for target classification and identification through a six-fold enhancement of current SAR resolution with ESAR and the ability to image moving targets and perform mensuration with ISAR. This upgrade assumes the PSP replacement is already implemented. The upgrade also increases both range and azimuth resolution. ESAR and ISAR are concurrent upgrades to reduce cost of Non-Reoccurring Engineering (NRE) and testing. ESAR requires 27.5K Software Lines Of Code (SLOC) and 34.5K SLOC for ISAR. The E-8 SAR resolution does not provide for classification or identification. The E-8 SAR resolution provides some target situational awareness and terrain mapping. ESAR and ISAR will contribute to more accurate targeting data and supports potential growth to Automatic Target Recognition. ISAR also supports maritime potential by using the translational motion of the targets. The primary applications support Theater Missile Defense (TMD) identification of high value mobile targets such as SCUD Transporter-Erector-Launchers(TELs). This capability also increases targeting capability, location and identification accuracy, and the potential for fratricide reduction.


The SAR Management upgrade is a software modification that allows for the storing of a nominal mission’s worth of SAR images in a centralized retrievable database. The estimated Software Lines Of Code (SLOC) count for this is 6K. The E-8 Operator Work Station (OWS) can only hold 16 SAR images in the local memory. This is basically a screen store and recall capability. This upgrade would provide the capability to store all SAR imagery collected during a nominal mission. The system will have a master SAR file with all the SARs saved as well as individual save files with OWS unique entries (a subset of the master file). When the Radar Management Officer (RMO) receives a request for SAR, the system automatically searches the SAR imagery database to determine if images have already been taken of the area. If imagery exists, the RMO will be notified and also be provided the option of satisfying the Radar Service Requests (RSR) with the existing imagery rather than tasking the sensor again. The database will be accessible from all OWS, include date/time and position data for each image, a search engine capability to recall images, and provide a SAR-to-SAR comparison capability.

There are four phases to the Joint STARS Link 16 Upgrade programs: Current Capability, TADIL J Upgrade (TJU), Theater Missile Defense (TMD), and Attack Support Upgrade. When added to the current capability, TJU provides a basic, rudimentary Link 16 capability for passing ground tracks to link participants. TJU is partially funded and will be operational by 4qtr FY99. TMD will add three messages and part of another message to provide Joint STARS the capability to identify, monitor and report Transporter Erector Launchers (TELs), TEL reload locations, and TEL hide locations. The ASU will add 25 Link 16 messages to the Joint STARS data base. The upgrades will allow Joint STARS to realize its attack support role by passing sensor to shooter information for target assignment, target sorting, target/track correlation, and various command and platform managemant taskings. The implementation of these messages will give Joint STARS a robust, command and control, full up battle management capability. Software development and implementation will occur concurrent with each program software annual release. The Link 16 upgrades will provide Joint STARS with the capability to contribute heavily to TMD, interdiction, SEAD, and CAS mision areas. The current Joint STARS Link 16 capability is very limited. The E-8 can transmit and receive airborne link participant location and identification (PPLI) messages, receive air track and track management messages, and transmit part of a ground track message. Without this upgrade, Joint STARS can not effectivly contribute to its attack support mission as called for in the Joint STARS ORD, CONOPS and theater employment documents. Primary communications between Joint STARS and fighter aircraft will remain voice radio, and without the upgrades, Joint STARS will realize only a small portion of its potential as a sensor to shooter platform for the Air Force. Concurrent rather than sequential development and implementation of these upgrades will provide substantial cost savings. This upgrade directly enhances TMD targeting mission execution. TJU is funded (except for $3.8M for ground support). TMD, ASU and Future enhancements are totally unfunded.

Joint STARS Intelligence Broadcast System initially provides receive-only capability the TRAP, TADIX, and TIBS broadcast nets. These nets provide near-real time updates from multiple intelligence sources at the SECRET level to support situational awareness, intelligence preparation of the battlefield, cross-cueing, radar scope interpretation assistance, battle management and mission planning. This upgrade improves Theater Missile Defense (TMD) support, Order of Battle (OB) databases, self defense awareness, situation assessment and attack planning. The broadcast information would be integrated into all the E-8 workstations to allow the individual operators to conduct overlay and comparison of Joint STARS sensor data and broadcast system data. Current intelligence broadcast capability is a limited receive only contingency enhancement which is not fully supported through program life cycle and will increase CLS costs if kept as the de-facto baseline capability. The contingency system is hardwired into a single worksattion and is not availble to all mission crew members. Without a robust intelligence broadcast system the mission crew must heavily rely upon other sensor platforms to provide this data over voice communications increasing voice net traffic and operator work load.

Joint STARS Automatic Target Recognition (ATR) provides Joint STARS operators with automated surface target recognition/identification. This enhances operator efficiency in high density situations and exponentially increases current capabilities for surface target identification. ATR provides higher mission crew situational awareness and increases support to battle management and attack support. In support of TMD, the system will be able to locate, track, and identify missile Transporter Erector Launchers (TELS) vehicles upon cueing from off-board sensors/sources. The ATR concept is based upon algorithms using processed radar data (Enhanced Synthetic Aperture Radar [ESAR] and Inverse SAR [ISAR]) and applying Radar Cross Section (RCS) or templating techniques to classify/identify ground and maritime targets. ATR is a computational technique which compares the SAR imagery with imagery templates of high value targets to quickly identify and locate those targets in the image. This requires a large detailed data base of potential target image templates and the processing capability to do comparisons with Joint STARS sensor data. This capability includes integration into all the E-8 operator work stations and assumes implementation of first the Programmable Signal Processor (PSP) and then secondly the ESAR and ISAR upgrades. The initial effort is to develop and demonstrate an ATR capability on Joint STARS. ATR is not yet at a stage for insertion into Joint STARS production models or retrofit of existing aircraft. The is no automated target recognition or identification capability on the E-8. Currently, mission crew must cognitively fuse off board sensor information, current situation awarness, and on board sensors to make any type of recognition call. This type of analysis produces a low confidence level and requires a level of training which is nor provided to operational mission crew members. ATR would allow for more timely and accurate target support and battle management decisions. The PSP replacement and ESAR/ISAR upgrades must be acomplished prior to development of the ATR capability

JSTARS Tagging is an unfunded requirement to develop and implement a Joint STARS Radar Responsive (R2) Tag System comprised of two types of R2 Tags and corresponding functionality on board Joint STARS aircraft. The Joint STARS radar has two primary modes of operation, Moving Target Indicator (MTI) and Synthetic Aperture Radar (SAR). The R2 Tags are designed to work with the rapid revisit, MTI mode of the radar, providing positive identification of targets equipped with the tag. The tagged targets will be visible to the radar operator whether they are moving or stationary, as long as they are located within the radar field of view. The R2 Tags are also designed to interface with Unattended Ground Sensors (UGS) to provide data collected by the UGS to Joint STARS operators on-board the E-8 aircraft. This data could be a frame of video image, time/date of acoustic sensor activation, or other data provided by an UGS sensor suite. The Radar Responsive Tag will allow the Joint STARS aircraft to positively identify any tagged vehicle, person, or structure. This capability addresses the need for wide area surveillance capability to Detect, Locate, Track and Identify time critical targets and correlate and fuse data.

Enhanced Joint STARS ATR is an unfunded requirement to provide an enhanced means of targeting critical mobile ground targets. The technical objective is to accelerate the transition of targeting enhancements to the Joint STARS system. These enhancements enable more effective targeting against Time Critical Targets (TCTs). There are two primary goals: (1) demonstrate the robustness of using Hi-Resolution Synthetic Aperture Radar (SAR) based Automatic Target Recognition (ATR) technology for improved identification of Time Critical Targets (TCTs) and; (2) demonstrate the effectiveness of using Hi-Resolution Moving Target Indication (MTI) sorting of targets in a scan mode to pick out target areas of interest in a non-cooperative mode. The approach is to upgrade software capability on-board Joint STARS to take advantage of available hardware and processing to allow for Enhanced Synthetic Aperture Radar (ESAR) and High Range Resolution (HRR) MTI. The ESAR capability will provide a resolution 6X the baseline resolution. The HRR/MTI provides target vehicle range extents and integrating this with a tracker capability provides vehicle target length measurements. Conceptually, the HRR/MTI is being used as a cueing mechanism for the detection of TCTs by length measurements. This cue is handed off to the ESAR algorithm for imaging the long length vehicles for the ATR to perform non-cooperative target ID of Tactical Erector Launchers (TEL). The current system performs ATR of TEL type targets in the clear (no obscurations of the target).

As early as 1992, the Boeing Company proposed putting the system on newer Boeing 767-200 Extended Range aircraft, but this proposal was not accepted at that time as cost-effective. Given the current 707 airframe procurement, refurbishment, and modification cost and a 1996 price for a commercial version Boeing 767-200 Extended Range aircraft of between $82 million and $93 million, it may now be more cost-effective for the Air Force to buy that or some other new, more capable aircraft. Such an aircraft could provide a longer life, greater room for growth, greater flight range, greater fuel efficiency, higher operational availability, and lower program life-cycle costs.