Gakona radar
EAS graduate students Aaron Kirchman and Germain Vega, together with advisor David Hysell, installed a new VHF radar in Gakona, Alaska this August. The radar, designed and fabricated at Cornell, is intended to observe so-called "polar summer mesospheric echoes" or PMSE. These radar echoes arise from turbulence in the mesosphere between about 80--90 km altitude. The turbulence appears in the tenuous electrons in the mesosphere which are created by solar ionization. The scattering cross-section of the turbulence is increased by the presence of charged ice grains which form in the polar summer mesosphere, the coldest place on earth. These ice grains make up polar mesospheric clouds, the highest clouds on earth. The radar will be used to study the complex physics of so-called "dusty plasmas" in the mososphere together with mesospheric chemistry, dynamics, and transport.
The radar employs software-defined receivers and solid-state transmitters and can be operated remotely and autonomously over the internet. The radar uses multiple, spaced antennas for reception and utilizes aperture synthesis imaging techniques familiar to radio astronomers to create three-dimensional images of the mesospheric scatterers. Animated sequences of images give a vivid account of mesospheric dynamics which can be combined with optical images and other in situ and remote sensing datasets, yielding an incisive picture of mesospheric phenomenology. The radar is situated nearby the HF heater which can modify the charging processes in the D region that affect the backscatter signal-to-noise ratio.
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