Abstract
We have started a regular operation of the Sound Detection and Ranging(SODAR) for understanding the observing conditions at the Subaru telescope, Mauna Kea. The element array of SODAR emits audible sounds and then detects doppler shifted echo and its strength from various altitudes. The echo strength is known to be proportional to the temperature structure constant(C 2 T ), and we can obtain the vertical profile of optical turbulence. We adopted REMTECH PA1 SODAR, which is capable of measuring meteorological parameters between 20 m and 1000 m above the ground. Because the echo strength obtained by the PA1 has arbitrary unit, we attempted to determine the conversion factor from the SODAR echo strength to C 2 T value by comparing with the data obtained by micro-thermal sensors simultaneously that were set on a 30 m tower placed near the SODAR. In May 2007, we made a calibration campaign at Okayama Astronomical Observatory(OAO) in Japan. We found the conversion factor is 3.0×10 -7 K 2 m -2/3 , however, the scatter of the correlation between the data of SODAR and micro-thermal sensors were large. We also found a possible artificial enhancement of echo strength in its altitude profile. We report the details of the calibration and preliminary results from the regular operation at the Subaru telescope since Feb 2008.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
