New Delhi, Jan. 30 :    New Delhi, Jan. 30:  The Indian navy has been carrying out a series of tests of the Trishul surface-to-air missile off the Kochi coast that began on January 25. At least two anti-missile missiles were fired from INS Dronacharya, a shore establishment, which is also home to the navy's gunnery training school. Naval sources refused to give details on the nature of the test that was monitored by the Defence Research and Development Organisation (DRDO). Though official sources said the testfiring was 'successful', it was not known if more tests would be needed. There has been no claim from the DRDO that the missile was ready for production and induction. Defence sources said: 'The missile was tested in sea-skimming mode against low-flying targets in the anti-sea skimmer role.' This would mean the testfired missile would have flown low and a little above the surface of the water for a small distance before zooming into its target higher up. During testfire, the target would have been a drone. The scientists would also be monitoring the missile's ability to fly as low as possible to avoid radar detection. The tests of the Trishul anti-missile missile under the Integrated Guided Missile Development Programme that began in 1983 are behind schedule. It was mainly because the programme has been behind schedule that the navy has begun importing and inducting the Barak anti-missile system from Israel. The Trishul missile is being developed for use by all three services.