May. A third was built for the LSA project. ESO installed it at Pajonales in 1997 April and will move it to Chajnantor in 1998 June. From the phase time series, we obtain the r. m. MMA Memo 129 describes the site test interferometer data reduction in detail, and MMA Memo 130 illustrates the agreement between two different methods of deriving the mean velocity of the turbulent water vapor flow in the atmosphere. The instrument operates autonomously.
Sporadic repair is required.
The data are retrieved on tape about once a month and analysed in Tucson. Summaries are posted monthly. A tipping photometer has been developed in collaboration with Carnegie Mellon University to directly measure the atmospheric transparency at 350 mu m wavelength. This instrument is based on an ambient temperature, pyroelectric detector. The spectral response is defined by a resonant metal mesh.