gas mixing and dispersion are major areas of interest in these experiments, and for this reason, we are Antenna setting up measurementstations (Fig. 7) Specifically designed to measure these effects. We are equipping the turbulence stations with fast, infrared gas sensors, temperature sensors, and fast-response 10 E . c bivane anemometers positioned 1, 3, and 8m above the ground. The development of a fast infrared gas sensor has been a majorproject for us this year.° This instrument, capable of measuring methane, ethane, and propane concentrations, is portable, fast (0.2 s cycle time), and able to operate in the fog. We developed it because no satisfactory commercial instruments were available. Bivane anemometer 3 . mm 3 Thermocouple Qa = oO _ co mp In the 40-m” tests, we are imag- ct) I 5 Humidity ‘ sensor ° Radiometer Battery acauiai 0 Heat flux sensor ISHHONn unit s Solar P anel BiG “i One of six turbulence stations being used in the 40-m?spill exuf Meese Y periments currently being performed at China Lake. The entire tower, excluding its base, weighs only about 22 kg and caneasily be moved from one base to another by two men in about a half an hour. The gas stations are similar, except that they do not include the fast-response bivane anemometers. ing the cloud from above by means of a helicopter-mountedinfrared imaging system with opticalfilters centered on a band in the infrared strongly absorbed by methane. This allows us to trace the cloud downwind long after it has become invisible to the naked eye and will be of great help in reconstructing cloud movements for comparison with the computer simulation. Weplan 10 or more 40-m? spills under a variety of wind-speed and spill-rate conditions. We would like to measure spills at very low wind speeds (1 to 2 m/s), but such con- ditions are rare at China Lake. Whendata from the current tests are analyzed, we should have enough information to proceed with the larger spils. Summary We have conducted 4 series of 5-m" spills of LNG to evaluate gas 36