The TAO project
Research on meteorological condition in the atmosphere with satellite data
Meteorological condition including a cloud coverage has been researched based on data by a weather-monitoring satellite (1993 - 1999). Around Chajnantor, a rate of photometric night is 70 % and a precipitable water vapor is extremely low, which means that the site is suitable for infrared observations.
Research on topographical features by field works
Carried out 8 field works until 2004
Research on meteorological condition near the ground with a weather monitor
Direction and speed of wind and temperature, humidity, and pressure of the air are always monitoring. Desired good results have been obtained in the flat area around Chajnantor. From April 2006, the weather observations have been started at the summit of Chajnantor.
Research on seeing condition with a seeing monitor
Atmospheric turbulence affects to observations because it causes vibration and expansion of stellar images. So, a stellar size (angle) spreaded by the turbulence, so called seeing size, has been measured and its effect has been evaluated. Very sharped stellar images with a seeing size of about 0.5 arcsec have been obtained around Chajnantor.
Research on meteorological condition in the atmosphere with an infrared cloud monitor
A cloud coverage in the all sky is always monitored by measuring thermal radiation from the cloud. It has been confirmed that good weather condition is very often obtained around Chajnantor. The meteorological observations have been carried out at the summit of Chajnantor since April 2006.