- Research Topics
- Department Optical Soundings and Sounding Rockets
- Department Radar Remote Sensing
- Department Modelling of Atmospheric Processes
- Cross-departmental Collaborations
The IAP metal lidar system is designed for the observation of layers of metal atoms in the upper mesosphere and lower thermosphere (roughly 75-140 km). The lidar utilizes resonant backscatter of the metal atoms after emission of laser radiation from two separately tunable dye lasers. The dye laser allows the easy change of the sounded metals. The metal lidar system complements the K lidar system by observation of density profiles of different metals like Fe, Ca, Ca+, Na and Ni. Furthermore the dye laser provides backscatter profiles at additional wavelengths for the examination of NLC.
The dye laser is pumped by the energy of an excimer laser beam. It is tuned with 0.1 pm resolution, using either the atmospheric backscatter or the signal of a metal vapour cell in the lab as a wavelength reference.
The dye laser was built in the 1980ies, the excimer laser in 1999. The whole system is very rugged and has also been used during different field campaigns outside a laboratory.
The detection system of the metal lidar uses a single 80-cm-mirror (focal length 3.2 m). The backscattered photons are guided by a glas fiber to a wavelength dependent mirror. Interference filters suppress the largest part of the background light before a photomultiplier detects the transmitted photons. The typical altitude resolution for the detection is 200 m.
The metal lidar is actually not in routine operation but can easily be activated if appropriate science questions are upcoming.
- M. Gerding, S. Daly und J. M. C. Plane, Lidar soundings of the mesospheric nickel layer using Ni(^3$F) and Ni($3D) transitions, Geophys. Res. Lett., 46, 408-415, doi:10.1029/2018GL080701, 2019.
- J. M. C. Plane, S. M. Daly, W. Feng, M. Gerding und J. C. G. Martín, Meteor-ablated aluminum in the mesosphere-lower thermosphere, J. Geophys. Res., doi:10.1029/2020JA028792, 2021.