Marin M. Anderson, Andrew P. V. Siemion, William C. Barott, Geoffrey C. Bower, Gregory T. Delory, Imke de Pater, Dan Werthimer
The Allen Telescope Array was used to monitor Mars between 9 March and 2 June
2010, over a total of approximately 30 hours, for radio emission indicative of
electrostatic discharge. The search was motivated by the report from Ruf et al.
(2009) of the detection of non-thermal microwave radiation from Mars
characterized by peaks in the power spectrum of the kurtosis, or kurtstrum, at
10 Hz, coinciding with a large dust storm event on 8 June 2006. For these
observations, we developed a wideband signal processor at the Center for
Astronomy Signal Processing and Electronics Research (CASPER). This
1024-channel spectrometer calculates the accumulated power and power-squared,
from which the spectral kurtosis is calculated post-observation. Variations in
the kurtosis are indicative of non-Gaussianity in the signal, which can be used
to detect variable cosmic signals as well as radio frequency interference
(RFI). During the three month period of observations, dust activity occurred on
Mars in the form of small-scale dust storms, however no signals indicating
lightning discharge were detected. Frequent signals in the kurtstrum that
contain spectral peaks with an approximate 10 Hz fundamental were seen at both
3.2 and 8.0 GHz, but were the result of narrowband RFI with harmonics spread
over a broad frequency range.
View original:
http://arxiv.org/abs/1111.0685
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