#IP 1138 14 - 20 July 2014
" D H V A N I " AN INDIGENOUS LOCATION OF BULLET ON TARGET SYSTEM (LOBOTS) FOR THE INDIAN ARMY
In the era of modern warfare, there is an immediate need to not only equip the Indian soldier with latest weaponry but also to revolutionize the techniques to train him for an efficient battlefield operation. Among the most basic skills of a soldier is marksmanship.
Marksmanship training requires positive and negative reinforcement of shooting techniques immediately after each shot is fired. It is not only essential to provide the marksman with an indication of where a bullet is fired at a target, but also provide a comprehensive statistics of how he/she has performed throughout his/her career as a marksman. Currently, the manual system used by the Indian Army involves the marksman firing shots at the target and subsequently walking up to the target (about 300m!) and identifying whether the shots were a hit or a miss. This primitive type of marksmanship training exhibits not only high turnaround times but is also inconsistent, unreliable, inaccurate and subjective.
Marksmanship training systems available from advanced countries for sale are mostly based on 1980s technology. Further they have exorbitant cost of ownership since they are not customized for the Indian environment and necessitate expensive after-sales service due to the black-box approach of the manufacturers.
The need was to develop a modern indigenous system which is tailor made to meet the requirements of the Indian Army at a cost lower than similar systems available elsewhere without compromising the performance.
Towards this end, the Experimental Aerodynamics Division at National Aerospace Laboratories, Bangalore and the Indian Army's Simulator Development Division, Secunderabad have jointly developed a state-of-the-art Location of Bullet on Target System (LOBOTS) named 'DHVANI' (Detection and Hit Visualization using Acoustic 'N'-wave Identification) for perfecting marksmanship skills by accurately determining the location of bullet impact and providing real-time feedback to the shooter.
The system is based on the basic principles of gas dynamics and aeroacoustics. Essentially, a bullet is a supersonic projectile which generates a shock wave from its leading edge, continuously at every point of its supersonic travel. At any instant along the bullet path, the shock wave envelope propagates in an invisible-cone continuously outward at an angle related to its Mach number.
The pressure wave in air caused due to the passing of the bullet results in a pressure profile known as the 'N' - wave because of its shape. If the rise in pressure and the associated frequencies fall within the range of audibility of human ear, the N-wave can be heard as a distinct sound. This sound is akin to the 'Sonic Boom' – the sound perceived on the ground when an aircraft flying overhead exceeds the speed of sound.
It is possible to determine the hit location of the bullet accurately by using an array of sensors to record the acoustic pressure rise due to the passing shock from the bullet and hence to detect the path of the incoming bullet. Using advanced algorithms developed at CSIR-NAL, the recorded signal from the sensors are analysed for the detection of the 'Nwave' and uses the geometrical shape of the shock wave to determine the co-ordinates of the bullet on the target. These co-ordinates are then wirelessly transmitted to a display at the shooter end. The whole process i.e. firing a shot to displaying at the shooter end takes less than a half a millisecond. At the shooter end, a multi-functional interactive GUI on a MIL grade laptop displays the results. A comprehensive database which will contain personnel details, shots fired and performance statistics ensures comprehensive logging for later analysis.
The entire process from the Indian Army's request to the prototype testing took only 10 months, and a shoestring budget of Rs 40L for two units, demonstrating that all military related R&D need not have protracted delays and costs. Each prototype currently costs Rs 9 lakhs/firer lane, which is significantly lesser than the Rs 15-18 lakhs for each firer lane of older generation wired systems offered to the Indian Army. When the lifecycle costs are added in, this indigenous system works out to only about 40% of the cost of an imported one.
Considering that there are over 2000 firing lanes all over the country, the saving to the national exchequer is significant.
The system has undergone rigorous field trials at Army ranges in Bangalore, Secunderabad and Infantry School Mhow. The formal handing over of DHVANI by Director CSIR-NAL to Commandant SDD Secunderabad took place on July 03, 2014.
SPECIFICATIONS
 A Multi-lane MIL-Standard, highly Ruggedized training System
 Accurate Hit Detection (within ±7mm)
 Immediate and detailed performance data using GUI display at the shooter and range controller levels (multiple lanes)
 Individual Shooter Performance data logging
 Auto triggered
 Lane detection – no credit to shooter if fired from other lane
 No susceptibility to interference from other simultaneous lanes
 Centralized Monitoring of lanes
 Wireless connectivity
 Completely field deployable in existing ranges
 Standard COTS hardware
 Capable of detecting burst mode from machine guns (2000 bullets/min)
 Caters to ranges up to 300m
 Extended to multi-lane ranges without limit or change in algorithm
 Cross-fire and Ricochet Detection
 Composite bar immune to changes in environmental temperature that can affect accuracy in metal bars as well as protection against rusting/oxidation
 Interfaced with Indian Army database of marksmen for improved training practices.
 Proprietary detection algorithm developed at EAD-NAL
 Significantly lesser setup and lifecycle costs(< Rs 0.75 Cr/ 8Lane Range) compared to Rs 2.4 Cr for similar foreign system – saving of nearly 60% in cost
