70 likes | 165 Vues
Astronomical Site Monitoring System. Adverse condition protection Take advantage of really good conditions Long term weather trends and predictions. Dan Klinglesmith 08/16/2002. ASMS. Sky conditions r 0 , τ 0 and θ 0 Extinction Meteorological conditions Wind speed & direction
E N D
Astronomical Site Monitoring System • Adverse condition protection • Take advantage of really good conditions • Long term weather trends and predictions Dan Klinglesmith 08/16/2002
ASMS • Sky conditions • r0, τ0 and θ0 • Extinction • Meteorological conditions • Wind speed & direction • Temperature, Relative Humidity, Pressure • Dew Point • Environmental conditions • Cloud cover • Particle density • Lightning detection • Seismic activity
Sky Conditions • Differential Image Motion Monitoring System • r0 • Sarazin & Roddier (1990, A&A, 227, 294) • 5 to 10 ms exposures • τ0 and Θ0 • Sarazin & Tokovinin ( Venice 2001, Beyond Conventional Adaptive Optics) • 1 to 5 ms exposures plus forecasts of winds aloft from NCAR
DIMM System • 16-inch Cassegrain telescope, DFM • 3rd magnitude and brighter stars ( 46 to choose from) • DIMM instrument inside telescope • 2 sub apertures • B, V, R and I filters • High Speed CCD outside telescope • 1 to 20 ms exposures • Sub frame rates > 500 Hertz • Fully automated operations • Star finding and tracking • Data collection and reduction • Data archiving
DIMM System • Automated operations continued • Operator displays and alerts • Broad band photometry • Extinction coefficients • Photometric stability
Meteorological sub system • Weather history • Long term history of weather conditions at MRO • Telescope protection • Stop operations when wind speed > “X” meters/second
Environmental sub system • Lightning detection • Working with Langmuir to determine proper lightning detection • Seismic activity • Working with IRAS/PASCAL to provide long term seismic detectors at each end and middle of the array • 1 – 1000 hertz frequencies and amplitudes • All sky camera • IR camera looking for general cloud cover and faint cirius • Westpfahl Turbulence monitor • Turbulence measured at 3 levels above ground • Correlate with DIMM measurements