Laser Science and Technology Centre (LASTEC), Delhi, has designed and developed an Optical Target Locater (OTL), a laser-based portable surveillance device, for detection of passive or active optical threats. The system functions in the cat’s eye effect. Any optical system, when illuminated by a laser beam, returns some back-scattered energy. This retro-reflected energy helps in locating optical targets against a static background. The system is an important tool for detection of any active or passive surveillance

A device using the retro-reflected signal from their front-end optics. Any surveillance device with front-end optics and a sensor at the focal plane, whether biological, i.e., eye or passive sensors like binoculars, day sight
or night vision device (NVD), or electronic sensors as in Laser Range Finders (LRFs) can be detected by this approach. The threat could be in terms of a sniper equipped with a day sight or an NVD, or any other optical/electro-optical surveillance device, viz., binoculars, surveillance cameras, LRF, designators, etc. Two variants of the OTL are being developed.

The development of short range version, OTL 300, for 300 m range has been completed. OTL 1500, the long-range version, is presently undergoing test and optimization process. OTL 300 finds application in active scanning and monitoring of specific areas, VIP security and detection of pointed optics. The equipment has been demonstrated
to potential users like Delhi Police, National Security Guards and Indian Army and was recently deployed for area sanitation and security on several occasions. Delhi Police is procuring OTL 300.