OPTRONIC MISSILE GUIDANCE SYSTEMS: ACCURACY, LOW SIGNATURE AND SIMPLICITY

Victor Solunin, Director and Chief Designer of the Central Research Institute of Automatics and Hydraulics
Boris Gursky, Deputy Director and Deputy Chief Designer of the Central Research Institute of Automatics and Hydraulics
 

The Central Research Institute of Automatics and Hydraulics (TsNIIAG) is one of Russia’s leading developers of high-precision guidance systems for long-range missiles.

Optical homing head

One of the ways to increase the accuracy of missile guidance systems against ground-based targets with a low signal/noise ratio (in contrast to air and sea targets) includes the integration of inertial guidance systems with terrain-comparison and map-matching (TCMM) systems operating in the optical, infrared and RF bands of the electromagnetic spectrum.

Advantages of these optronic missile guidance systems over radar guidance systems include high resolution, the use of only passive operating mode (in other words, no signals are emitted), and a compact size and low weight of the onboard equipment. To sum up, they feature high accuracy, low signature to radar systems, and overall simplicity. TsNIIAG began work on these optronic TCMM missile guidance systems in the mid-1960s. When the system’s architecture and data handling concepts were being developed, it was decided that, unlike high-yield nuclear missiles, high-accuracy conventional-tipped missiles must include three prominent features: an operational target reconnaissance system, a precision target designation system, and a reference data gathering system. The target reconnaissance system must be capable of operating in the entire spectrum of missile firing ranges, and also include segments of space and aerial reconnaissance. The target designation system, on the basis of reconnaissance video data obtained, sends precise target coordinates to the missile’s inertial navigation system, while the reference data gathering system furnishes land-surface images to the TCMM system.

To create an optronic guidance system, it was necessary to develop highly-sensitive small-size sensors and ground-based information systems for receiving and processing images, generating target designation and reference data, and finally, to promptly transmit the data to the missile launch sites.

In the 1970s, TsNIIAG carried out research to determine the possibility of developing an optronic guidance system for ballistic missiles in service with the land forces. The institute’s specialists conducted research into the image recognition and processing theories, and laid the foundation of systems engineering and software for the development of ground-based data gathering equipment and onboard real-time land-surface imaging equipment.

Their efforts resulted in the development of an optronic terrain-comparison and map-matching guidance system which was tested on board a flying laboratory. The system showed notable accuracy over various landscapes. Finally, a series-produced ballistic missile equipped with an optronic guidance system was launched. The deviation of the point of impact of the re-entry projectiles from the target was only a few meters, which fully confirmed the great potential of these optronic missile guidance systems.

In the 1980s, the Institute began to develop an optronically-guided re-entry vehicle for the R-17 ballistic missile. TsNIIAG specialists developed software, an optronic guidance system, onboard equipment for the re-entry vehicle control system, ground-based data gathering equipment, and re-entry vehicle targeting equipment. To ensure the reliability of the guidance system in any weather, and over any terrain, a target/background databank was developed. It contained more than 10,000 images of the Earth’s surface made at different times of day and in different seasons of the year. The mathematical modelling of the system’s work, with the help of the target/background databank, made it possible to evaluate the system’s accuracy and operating characteristics in its entirety. After a series of ground tests the system’s equipment components and software were substantially improved. During hundreds of flights, the system’s accuracy and operating reliability in any weather and over any terrain were assessed.

At the final stage of the tests, missiles fitted with target re-entry vehicles were launched. Their point-of-impact error did not exceed a few dozen meters. The work on the R-17 missile equipped with an optronic guidance system was successfully completed, and the missile was subsequently placed in operational service. Many years have passed since then and we see that our world has changed dramatically. Military doctrines and strategies have changed just as radically. New types of armaments have been developed; components used in electronics and computing systems have been considerably upgraded; and software has become more sophisticated and infinitely more powerful.

At present, the optronic guidance systems are based on state-of-the-art optronic units, high-speed computers and sophisticated software. As we approach the dawn of the 21st century, these systems still hold high prospects for use with various precision guided missile weapons.

In some climatic zones these systems cannot be used with ballistic missiles because of unfavorable weather conditions (low clouds and frequent precipitation), which make the target area marginally discernible from high altitudes. At the same time, weather conditions cease to be a decisive factor for optronic systems mounted on low-altitude air-, ground-, or sea-launched cruise missiles. The use of optronic guidance systems in the U.S.-made Tomahawk cruise missiles provides an excellent example of this concept.

Optronically guided cruise missiles are more efficient in overcoming anti-missile defense zones, and, furthermore, do not deviate from their target by more than a few meters.

Presently, serious attention is being given to the system’s ground-based infrastructure, which is responsible for the data preparation and subsequent launching of missiles equipped with the TCMM guidance systems. Achievements in the development of information technologies, microelectronics, optics, computers, image-processing systems, and communications equipment make it possible to develop powerful reconnaissance image transmitting and processing systems; high-accuracy image-processing and target designation systems, reference data compilation systems; as well as high-speed systems designed to transmit data to missile launch commands. The development of such highly accurate and powerful equipment for onboard and ground-based missile guidance systems makes it possible to combine several launch processes together: reconnaissance, target designation confirmation, battle management, data gathering and preparation of mission profiles, missile launching, missile guidance and target engagement. This, in turn, assists in the overall process of quickly, and efficiently destroying targets with long-range, conventional-tipped missiles.