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Published byJudith Stafford Modified over 8 years ago
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SLODAR Turbulence Profilers Richard Wilson, Tim Butterley, James Osborn Durham University, UK
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SLODAR (SLOpe Detection And Ranging) Shack-Hartmann wavefront sensor Observe double stars Recover C n 2 (h) from the time- averaged cross-covariance of the WFS data
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hh SLODAR Altitude Sampling h d/ d (WFS sub-aperture size)
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hh Higher Altitude Total SLODAR Altitude Sampling: Ground-Layer profiling
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SLODAR Turbulence Profile Sequence, Paranal
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SLODAR: Turbulent Layer Velocities Movie shows the spatial cross- covariance with increasing time offset. Motion of peaks => layer velocity (with altitude). Altitude
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SLODAR at ESO Paranal: Ground-Layer Characterization
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SLODAR Turbulence Profile Sequence, Paranal
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All quiet in the ‘gray zone’… Surface layer not resolved SLODAR Turbulence Profile Sequence: Paranal
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SLODAR at Paranal Mean Ground-Layer Turbulence Profile Free-Atmosphere Total ~ 45% of optical turbulence within ~70m of the ground
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SLODAR Cross-Verification Compare with MASS and DIMM Cannot use the same targets for SLODAR and MASS-DIMM * SLODAR -- DIMM SLODAR MASS-DIMM
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SLODAR Cross-Verification: Total Seeing versus DIMM (Paranal) SLODAR DIMM
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SLODAR Cross-Verification: Total Seeing versus DIMM (Paranal) Subtract 7x10 -14 m 1/3 for the first 5m ??? Need ~5m resolution to confirm this …
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SLODAR Cross-Verification: Free Atmosphere Seeing versus MASS (Paranal)
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SLODAR-LOLAS at Mauna Kea: Ground-Layer Characterization Campaign
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Ground-Layer Turbulence: Mauna Kea
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SLODAR at SALT: Generalized Profiler - High Altitudes (~15km) Characterize SALT site for AO SLODAR Automation
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Correlating surface layer turbulence speed with physical ground wind speed (Mauna Kea data, first try …) : Meteorology: Turbulence Wind Speed UT (hours) Physical Wind Speed (m/s) Turbulence Speed (m/s) Wind Speed
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MM5 Model, C n 2 (h) and Wind Velocity Mauna Kea Weather Center Optical Turbulence Forecasting: Model Verification ? Wind Vw(h) C n 2 (h) ?
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