MASS

MASS was installed at Paranal in February 2003 (test night) under the guidance of A. Tokovinin (Assembly and Check-up). It is located at ground level close to the automated DIMM (West and East views). Mass is protected during daytime by a reflective blanket.

Description of the graphs

The central thumbnail is a hardcopy of the user configurable real-time MASS display showing, from top to bottom: the average flux in aperture D, the scintillation indices in apertures A, D, and differential A-B, the 0.5-25km seeing, tau0, teta0 and a false colour representation of Cn2 vertical distribution as a function of time.
The post-processing graphs are obtained using scripts developped by A. Tokovinin:
-The floating layer reconstruction assumes 3 layers of unknown altitude and intensity.
-The fixed layer reconstruction assumes 6 layers of known altitude (0.5, 1, 2, 4, 8, 16 km) but of unknown intensity.
-The integrated seeing of the Paranal DIMM is compared to the sum of the turbulence detected by MASS in the layers 0.5-25km and 2-25km
-The coherence time computed from the Paranal DIMM (using local and ECMWF high altitude wind speed) is compared to the MASS tau0. The floating and fixed layer representations include cloudy sky periods while the boundary layer and free-atm. seeing plots are built only from data filtered along:
i) relative background < 3% ii) Chi2 < 50 and iii) seeing error < 0.1.

MASS Campaign February '03 : 09-11 February 2003

Night beginning	Graphic data	Operations log Report
2003-02-10	Floating Layers, Fixed Layers, Seeing, Tau0	Test night
2003-02-11	Floating Layers, Fixed Layers, Seeing, Tau0	Test night