215 GHZ VLBI OBSERVATIONS - DETECTION OF FRINGES ON THE 1147 KM BASE-LINE PICO-VELETA - PLATEAU-DE-BURE

In a VLBI test experiment between the IRAM 30-m telescope at Pico Vele ta, Spain, and one 15-m telescope of the IRAM interferometer on Platea u de Pure, France, we detected fringes at 215 GHz with signal to noise ratios between 6.8 and 10.2. On this 1147 km long distance, of 0.28 - 0.43 milli arcseconds projected fringe spacing at 215 GHz, we have 8 independent detections of the sources 3C273, 3C279 and 2145+067. The c lock and fringe rates at 215 GHz are consistent with those derived fro m VLBI measurements at 86 GHz made at the beginning or end of the 215 GHz observations. The coherence times at 215 GHz were of the order of 10 seconds, most probably limited by the atmosphere.