Demonstration of a High-Rate Tactical Reconnaissance System with Real-Time Airborne Image Exploitation

J.N. Lee, D.C. Linne von Berg, M.R. Kruer, and M.D. Duncan
Optical Sciences Division

Introduction: The NRL Optical Sciences Division has been at the forefront of reconnaissance system development. The division has not only developed basic technology, such as large focal plane arrays, but has also designed, implemented, and demonstrated complete prototype systems. NRL demonstrated the first all-digital tactical reconnaissance system for the Navy, TARPS-CD (Tactical Air Reconnaissance Pod System—Completely Digital). In 2001, NRL demonstrated a prototype of the SHAred Reconnaissance Pod (SHARP) system for the F/A-18 Super Hornet; virtually all the features of this prototype have carried over into the Engineering and Manufacturing Development (E&MD) phase of the SHARP program. In the meantime, activity on the TARPS-CD effort for the F-14 has continued as risk reduction for advanced capabilities being considered for inclusion into the SHARP system. As part of the TARPS-CD effort, we have produced an upgraded digital reconnaissance pod payload to address fleet user responses to the original TARPS-CD system. The resultant pod system, denoted as Full-Capability (F-CAP), is based on the SHARP prototype architecture and is a test bed for advanced technology for SHARP. Figure 4 is a view of the F-CAP pod and its payload. Among the improvements we have implemented are:

• The NRL-developed Airborne Real-time Image Exploitation System (ARIES), with a new cockpit control box that allows the aircrew to examine and select imagery in real time;
• A high-performance Inertial Navigation System (INS), tightly coupled to GPS, mounted internal to the pod to provide accurate sensor attitude and position data for target geolocation;
• A solid state digital recorder that allows rapid access of imagery for routing and processing;
• Automated mission execution, system debug, and mission review via mission and maintenance PCMCIA memory cards; and
• A directional antenna for increased Common Data Link (CDL) transmission range.

FIGURE 4
F-CAP payload components and their location within the TARPS pod.

Special Cockpit Control Panel: One key improvement we have made with F-CAP is the incorporation of the ARIES circuit card into the Reconnaissance Management System (RMS) for in-cockpit display, processing, and geolocation of images obtained from the TARPS-CD digital framing camera. We designed and built a special cockpit control panel to allow the aircrew to quickly manipulate the image data on the cockpit display (e.g., pan, zoom, and roam) and create an image segment. This image segment can be a full-sized camera image reduced in resolution or it can be a smaller area of the full image, but with higher, or even full, resolution. Images are automatically annotated with useful information such as latitude and longitude. The annotated image segment can then be transmitted via the Fast Tactical Imagery (FTI) low-bandwidth (10 kbps) radio link to either an aircraft carrier, a strike aircraft, or ground special forces for target prosecution. FTI can also relay images from aircraft to aircraft, allowing transmission over the horizon. This capability enables an entirely new way to identify and prosecute time-critical targets. Figure 5 is an example of an image that was captured by air crew and transmitted by FTI.

The current TARPS-CD system uses knowledge of sensor attitude and location to perform aero-triangulation to determine the latitude and longitude of targets within an image. The original TARPS-CD design relied on the aircraft's INS data to determine sensor attitude; such an approach is inadequate for the precision targeting needed by new, GPS-guided weapons. The improved F-CAP design uses a separate, high-performance INS in the pod. This improved design uses GPS to augment the INS and has been shown to operate successfully in early flights of the F-CAP pod, although measurements of the increased precision using this approach have not yet been completed. This new design will allow the insertion of new technology in passive aero-triangulation techniques as they are developed. In addition to INS improvements, digital terrain elevation data are being incorporated into the ARIES system to allow more accurate geo-location in mountainous terrain.

Improved F-CAP: We have also improved the F-CAP system over the original TARPS-CD system by replacing the older, mechanically based digital tape recorder with a solid-state recorder. The solid-state recorder in F-CAP has over 30 GB of nonvolatile flash memory and records data at up to 40 MB/s. Because such a recorder has random access memory, any data stored in the system can be retrieved very quickly. When operated by the F-CAP RMS, the solid-state recorder allows near-instantaneous retrieval of previously recorded full-resolution imagery. This imagery can be sent to the cockpit by the ARIES card and can be transmitted to the ground or to ships via the 274-Mbps CDL link.

The transmission of real-time and recorded imagery to the ground is an important function of the TARPS-CD system. The original TARPS-CD system used an omnidirectional antenna in a small rf enclosure for CDL transmission in the X-band. We placed a small horn antenna within the same rf enclosure for the F-CAP pod. Using input navigational data, the CDL hardware automatically steers the horn in the azimuthal direction at a fixed depression angle to point toward a designated latitude and longitude position. This design allows 274-Mbps CDL to be received at up to 180 nautical miles, ~2.5x the range of the original antenna. We have demonstrated the successful downlink of imagery with this new design.

"Automode": The original TARPS-CD system was able to record image data only when commanded to do so by a pilot operating the pod control panel in the F-14 cockpit. This meant that a busy pilot might leave the system on continually, resulting in a huge amount of extraneous data, or that targets might be missed. To help solve this problem, we implemented an automatic mission mode for the F-CAP system. This "automode" can be programmed onto a PCMCIA memory card using a laptop computer and graphically based mission-planning software we developed. The automode information can include the location of point targets, area targets, and strip targets, as well as the location of the CDL receiver. The automode information is read into the RMS prior to an actual mission. If the pod is switched to automode, then the entire mission can be executed automatically, with the camera, recorder, and CDL data link turned on and operated automatically as the aircraft approaches the appropriate locations. In addition to storing the automode program, the PCMCIA card is used to store the sequence of events that actually occurs during the execution of a mission, even when the mission is run completely manually. Finally, in the F-CAP pod another PCMCIA card records every operator action and anomaly report during a mission, allowing mission review and identification or any hardware, software, or operator errors.

Evaluation: The F-CAP pod was evaluated in operational exercises by F-14 squadron VF-32 at NAS Fallon in July 2002 and aboard the carrier USS Harry S. Truman (CVN-75) in September and November 2002. The F-CAP pod and spare electronic components accompanied VF-32 and the Truman on its deployment in December 2002.

[Sponsored by NAVAIR]