We present an estimator of the bispectrum, a measure of three-wave couplings. It is evaluated directly in the wave number domain using a limited number of detectors. The ability of the bispectrum estimator is examined numerically and then it is applied to fluctuations of magnetic field and electron density in the terrestrial foreshock region observed by the four Cluster spacecraft, which indicates the presence of a three-wave coupling in space plasma.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science