HELINA, K.S.Varaprasad, DRDL, DRDO
NAG - For Mechanised Infanry with 4km range, LOAL – fully autonomous after launch
Helina – Use existing technogy on Nag with some additional LRU's (radio link or fiber optic link)and increase range to reduce development cycle time and achieve immediate time compatibility with LCH. Parallel effort develop an indigenous high-rez seeker with 7+km stand-off range.
Making Nag compatible for 7.5Km range:
Improve propulsion – either sustainer or booster
Guidance aid – with current seeker not possible to see beyond 3km, so we need a guidance aid. So decided on a two-way, secure,jam-proof RF datalink. Command & guidance upwards, video & health monitoring downwards,
LOAL scheme using RF link:
1.WSO acquires target through EOp
2. Align Helo to the required Azimuth & put the TAS in auto-tracker mode; LRF fired to get target ranging, seeker slaved to TAS
3. Based on range determined from LRF, the onboard computer decides the trajectory – top-attack or flat trajectory (WSO has the authority to override if required)
4. WSO places a target-gate and fires the missile
5. Missile maintains a course +/-1deg in azimuth while the seeker maintains a FOV of 3deg (to be later reduced to 2deg). As the missile closes in the pilot gets a clear video of the target through downlink.
6. Based on the video feed he gets, WSO can adjust the target-gate to give mid-course guidance.
7. The WSO can guide the missile all the way through OR choose to put it in "LOCK" mode and let the auto-guidance take over
The auto-jam features of the RF-link and the resolution of the video play a major role. Only these two are developed for HELINA, everything else is same as in NAG.
FCS provides interface with the Helicopter through launcher interface unit (LIU). 4 launchers with 4 launcher interface units each capable of controlling 2missiles = 8 HELINA max possible for each LCH. Each launcher is autonomous by itself. There is one RF-data transmission system on each side of the helicopter. Each LIU has its own cooling system with a time of 2hrs for 2missiles (as per the sortie time specified by the user)
Launcher has to be isolated from the vibration of the Helicopter frame. Within the required weight limits the launcher has been developed and captive flight tested – no worries on this part.
After the sortie only the two missiles (within their tubes) per launcher have to be changed. The launcher need not be changed. It will take only 2mins to change the two missiles housed in the tubes.
Has multi-carrier CDMA & multi-code CDMA to make sure the command guidance of two Helo's flying together (300m apart and so on) doesn't get mixed up (this was in response to a question).
Tandem warhead able to defeat 800mm thick (ERA) armour - great success with NAG.
Future growth potential:
Non-LOS targets
Weaponization of UAV's for BVR targets
From BR