J/A+A/565/A102 Mesospheric sodium properties (Pfrommer+, 2014)
High resolution mesospheric sodium properties for adaptive optics applications.
Pfrommer T., Hickson P.
<Astron. Astrophys. 565, A102 (2014)>
=2014A&A...565A.102P 2014A&A...565A.102P
ADC_Keywords: Earth
Keywords: atmospheric effects - instrumentation: adaptive optics -
site testing - methods: observational
Abstract:
The performance of laser guide star adaptive optics (AO) systems for
large optical and infrared telescopes is acted by variability of the
sodium layer, located at altitudes between 80 and 120km in the upper
mesosphere and lower thermosphere. The abundance and density structure
of the atomic sodium found in this region is subject to local and
global weather ects, planetary and gravity waves and magnetic storms,
and is variable on time scales down to tens of milliseconds, a range
relevant to AO.
It is therefore important to characterize the structure and dynamical
evolution of the sodium region on small, as well as large spatial and
temporal scales. Parameters of particular importance for AO are the
mean sodium altitude, sodium layer width and the temporal power
spectrum of the centroid altitude.
We have conducted a three-year campaign employing a high-resolution
lidar system installed on the 6-m Large Zenith Telescope (LZT) located
near Vancouver, Canada. During this period, 112 nights of useful data
were obtained.
Description:
UBC Lidar Data Conversion Programs
This software may be freely distributed and used by anyone. No
warranty or representations are made concerning this software, and no
liability of any kind will be accepted in connection with its use.
Please report any bugs to
To install, cd to the directory containing this file and the source
code and run
$ make
The binary files 'centroid', 'density' and 'fileinfo' will
be generated. You can move them to a more convenient directory (eg.
/usr/local/bin).
Information on the lidar data format, and the use of these programs
can be found in the data_format.pdf document.
P. Hickson, 2014
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fits.dat 59 134 List of FITS files
fits/* . 134 Individual FITS files (total is 125Gbytes)
data_format.pdf 512 927 LIDAR data format and software explanations
LZTlidar-1.0f.tar 1056 1429 All files needed to read the fits files
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Byte-by-byte Description of file: fits.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- FileName Name of the fits file in subdirectory fits
19- 23 I5 --- N [420/29545] Number of "blocks" of 50 shots
of data
25- 34 A10 "YYYY-MM-DD" Start.date UTC date of observation
36- 43 A8 "h:m:s" Start.time Starting time of observation
45- 52 A8 "h:m:s" End Ending time of observation
54- 59 F6.1 Mibyte Size Size of the FITS file
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Acknowledgements:
Thomas Pfrommer, tpfromme(at)eso.org
(End) Patricia Vannier [CDS] 09-May-2014