Magnetometry with mesospheric sodium.

Atmospheric Sodium Column Density Monitoring

In Laser Guide Star Adaptive Optics (AO), a laser is used to excite the mesospheric (90km altitude) sodium (Na) layer and thereby creates an artiicial star that can be used as reference for the AO wavefront sensor. The intensity of the created star depends strongly on the amount of Na present in the atmosphere. Experiences to measure the column density and details of excitation of scattering pr...

A System for the Monitoring of the Mesospheric Sodium Layer Using a Magneto-optical Filter

A general use of the adaptive optics require an artiicial guide star created by focusing a laser beam tuned to the sodium D 2 line. We propose here a system to monitor the column density of the mesospheric sodium layer which is based on the sodium magneto-optical lter (MOF) already widely used in solar observations. The principal characteristics of this system are high transmission and high spe...

A new time-resolved model of the mesospheric Na layer: constraints on the meteor input function

Advanced mesospheric temperature mapper for high-latitude airglow studies.

Over the past 60 years, ground-based remote sensing measurements of the Earth's mesospheric temperature have been performed using the nighttime hydroxyl (OH) emission, which originates at an altitude of ∼87  km. Several types of instruments have been employed to date: spectrometers, Fabry-Perot or Michelson interferometers, scanning-radiometers, and more recently temperature mappers. Most of th...

Measuring the Absolute Height and Profile of the Mesospheric Sodium Layer using a Continuous Wave Laser

We have developed and tested a novel method, based on LIDAR, of measuring the height and profile of the mesospheric sodium layer using a continuous wave laser. It is more efficient than classical LIDAR as the laser is on for 50% of the time, and so can in principle be used during laser guide star adaptive optics observations. It also has significant advantages over direct imaging techniques bec...