Core Processor
Hosting the mission systems software is the JSF's electronic brain, the ICP. Packaged in two racks, with 23 and eight slots, respectively, this computer consolidates functions previously managed by separate mission and weapons computers, and dedicated signal processors. At initial operational capability, the ICP data processors will crunch data at 40.8 billion operations/ sec (giga operations, or GOPS); the signal processors, at 75.6 billion floating point operations (gigaflops, or GFLOPS); and the image processors at 225.6 billion multiply/accumulate operations, or GMACS, a specialized signal processing measure, reports Chuck Wilcox, Lockheed's ICP team lead. The design includes 22 modules of seven types:
Four general-purpose (GP) processing modules,
Two GPIO (input/output) modules,
Two signal processing (SP) modules,
Five SPIO modules,
Two image processor modules,
Two switch modules, and
Five power supply modules.
The ICP also will have� "pluggable growth" for eight more digital processing modules and an additional power supply, Wilcox adds. It uses commercial off-the-shelf (COTS) components, standardizing at this stage on Motorola G4 PowerPC microprocessors, which incorporate 128-bit AltiVec technology. The image processor uses commercial field programmable gate arrays (FPGAs) and the VHDL hardware description language to form a very specialized processing engine.The ICP employs the Green Hills Software Integrity commercial real-time operating system (RTOS) for data processing and Mercury Computer Systems' commercial Multi-computing OS (MCOS) for signal processing. Depending on processing trades still to be made in the program, the JSF also could use commercial RTOSs in sensor front ends to perform digital preprocessing, according to Baker. The display management computer and the CNI system also use the Integrity RTOS. COTS reduces development risk and� ensures an upgrade path, according to Ralph Lachenmaier, the program office's ICP and common components lead.
Tying the ICP modules together like a backplane bus and connecting the sensors, CNI and the displays to the ICP is the optical Fibre Channel network. Key to this interconnect are the two 32-port ICP switch modules. The 400-megabit/sec IEEE 1394B (Firewire) interconnect is used externally to link the ICP, display management computer and the CNI system to the vehicle management system.
Low-level processing will occur in the sensor systems, but most digital processing will occur in the ICP. The radar, for example, will have the smarts to generate waveforms and do analog-to-digital conversion. But the radar will send target range and bearing data to the ICP signal processor, which will generate a report for the data processor, responsible for data fusion. Radar data, fused with data from other onboard and offboard systems, then will be sent from the ICP to the display processor for presentation on the head-down and helmet-mounted displays.
EW System
The electronic warfare suite, integrated by BAE Systems, includes:
All-aspect radar warning capability, supporting analysis, identification, tracking, mode determination and angle of arrival (AOA) of mainbeam emissions, plus automatic direction finding for correlation with other sensors, threat avoidance and targeting information;
Defensive threat awareness and offensive targeting supportacquisition and tracking of� main beam and side lobe emissions, beyond-visual-range emitter location and ranging, emitter ID and signal parameter measurement;
A multispectral countermeasures suite with countermeasures response manager function, standard chaff and flare rounds; and
Passive EW apertures.
The EW suite complements the field-of-view and frequency coverage of the radar by providing complete coverage around the aircraft at a wider frequency range. Passive radar warning system aperturesat three different frequency ranges are embedded in the skin of leading and trailing wing edges and horizontal tail surfaces. The EW system also can use the radar antenna for electronic support measures (ESM). Expected mean time between failure (MTBF) is 440 hours.
The radar warning system is active all of the time, providing both air and surface coverage. Packaged in two electronics racks, it includes cards for radar warning, direction finding and ESM. The system uses DAS inputs directly, as well as fused inputs from the ICP. Digital processing allows reprogramming and increases reliability.
Vehicle Management System
One of the most important non-ICP processing functions is the vehicle management system, which handles flight control and utility systems such as fuel management and electrical and hydraulic system controls. BAE Systems designed the vehicle management computer (VMC), three of which are connected together via an IEEE 1394B bus. About the size of a shoe box, each computer contains a processor card, I/O card and power supply card.
All three VMCs process data simultaneously, constantly comparing results across channels to assure data integrity. In the case of divergent data, two processors can "vote" one processor or signal out, explains Bill Dawson, JSF program manager for BAE Systems Aerospace Controls.
Interfacing to the VMCs are remote I/O units provided by Smiths. These devices10 per aircraftare an integral part of the vehicle management network, receiving flight control and other inputs from hundreds of digital, analog and discrete sources, processing� the data and outputting the results to the VMCs over the 1394 bus.
Head-Down and Helmet Displays
The Joint Strike Fighter's flight deck display moves beyond the F/A-22's multifunction display-type layout to a single, panoramic, 8-by-20-inch� viewing area, the largest ever in a fighter aircraft. Developed by Rockwell Collins (Kaiser Electronics), the multifunction display system (MFDS) comprises two adjacent 8-by-10-inch projection displays, each with a resolution of 1280-by-1024 pixels. Each half is fully functional, so the system can continue to operate if one half fails.
The MFDS will present sensor, weapons and aircraft status data, plus tactical and safety information. The viewing area can be presented as a large tactical horizontal situation display or be divided into multiple windows.
Functions are accessed and activated by touchthe first touch screen on a large-format displayor by hands-on-throttle-and stick (HOTAS) commands. Each 8-by-10-inch area has an integrated display processor for low-level data crunching and a "projection engine" to cast the image onto the screen. The MFDS uses micro-active matrix liquid crystal display (LCD) image sourcesthree per projection engineilluminated by arc lamps. Collins will provide the display drivers and the first layer of services software, which Lockheed Martin will use to implement display applications.
Collins will procure glass commercially, tempering it with proprietary chemical processes. The Collins display processor _circuit card assembly design also is used for the display management computer-helmet (DMC-H). The assembly uses Collins application-specific integrated circuits (ASICs), as well as commercial processors, memory and graphics chips. Flight qualification and safety testing will begin once initial display systems are delivered in the second quarter of 2004. Standby 3-by-3-inch active matrix LCD flight displays are provided by Smiths Aerospace.�
The F-35's helmet-mounted display system (HMDS) will replace the traditional head-up display (HUD), "allowing for a tremendous cost savings and, more importantly, weight reduction," asserts Louis Taddeo, director of business development with HMDS designer, Vision Systems International (VSI). VSI is a joint venture partnership between Collins and EFW Inc., an Elbit Systems Ltd. subsidiary.
The HMDS uses a combination of electro-optics and head position and orientation tracking software algorithms to present critical flight, mission, threat and safety symbology on the pilot's visor. The system allows the pilot to direct aircraft weapons and sensors to an area of interest or issues visual cues to direct the pilot's attention, Taddeo explains. The HMDS comprises the helmet-mounted display, DMC-H, and helmet tracking system. VSI also supplies the joint helmet-mounted cueing systems used on the F-15 and F/A-18E/F aircraft.
Fundamental requirements for the HMDS include visor-projected, binocular, wide field-of-view, high-resolution, near real-time imagery and symbology; equivalent accuracy to head-up display systems; 24-hour usability; and fit, comfort and safety during ejection. Proper weight and balance are crucial in minimizing pilot fatigue resulting from high-g maneuvers and reducing head and neck loads in ejections, Taddeo stresses. The F-35 helmet is expected to weigh 4.2 pounds (1.9 kg).
The F-35's HMDS employs a flat panel, active matrix LCD, coupled with a high-intensity back light, as its image source. The partially overlapped display provides a binocular image 50 degrees wide by 30 degrees high.
The digital image source provides both symbol writing and video capability. The system includes a clear, optically coated visor for night operations and a shaded visor for daylight operations. Imagery is provided via the distributed aperture system (DAS) or a helmet-mounted day/night camera. F-35 pilots can select imagery and symbology via HOTAS commands.
F-35's CNI System
The two-rack communications, navigation and identification (CNI) system processes waveforms internally, sending high-level status data to the core processor. The CNI system is designed to provide functions such as beyond-visual-range identification friend-or-foe (IFF); secure, multichannel, multiband voice communications; and intraflight data link (IFDL) exchanges, synchronizing the displays of multiple aircraft. The CNI suite will support 35 different com, nav and identification waveformsabout 5 pounds (2.26 kg) per waveform function, compared with the legacy black box approach of 10 to 30 pounds (4.54 to 13.6 kg), or more, per waveform, according to Frank Flores, JSF program director for Northrop Grumman Radio Systems.
Software-defined radio technology means that the suite can provide numerous radio functionsranging in frequency from VHF to K bandfrom a set of more general-purpose module types, including:
Wideband RF module, performing analog-to-digital conversion, waveform processing and digital signal processing.
Dual-channel transceiver module, which can receive and digitize waveforms over a wide frequency band and generate� waveforms for transmission, driving ��� power amplifiers. This module supports most of the 35 waveforms.
Frequency-dependent power amplifiers, including L-band, VHF/UHF, and higher-frequency units.
Power supply module.
CNI processor module, which performs signal processing, data processing and comsec processing.
And an interface module.
Northrop Grumman developed middleware, located between the operating system and the applications. This layer of software is designed to allow smooth system growth and compatibility with Joint Tactical Radio System (JTRS) waveforms.
The CNI suite uses Green Hills Software's Integrity commercial real-time operating system, PowerPC processors, field programmable gate arrays and digital signal processors. Radio Systems is streamlining the design to minimize footprint.
Some of the suite's baseline functions include: VHF/UHF voice, HaveQuick I/II, Saturn (HQ IIA), satcom T/R, IFF/SIF (selective ID feature) transponder, IFF Mode IV interrogator, ILS/MLS/MLS/Tacan, IFDL, Link 16 T/R, Link 4A, tactical data information link (TADIL-K), 3-D audio, TACFIRE/Air Force applications program development (AFAPD), and ADS-B.
