Automated detection of solar radio burst and plasma structure observed with WIND/WAVES

Multi-spacecraft space science missions such as CLUSTER (launch 2000) and Magnetospheric Multi Scale (launch 2008) carry radio receivers that operate below the ionospheric limit of 10-15 MHZ down to a few kHz and produce large amounts of in situ and remote observations of a great variety of Solar System phenomena. Radio signatures of the plasma in the immediate vicinity of the spacecraft contain information about important plasma parameters such as the local temperature and density that characterize structures in the space plasma and can be used to calibrate other instruments. The large data rates are a great challenge for both control and communication, which may be addressed by moving some traditionally ground-based science data processing and analysis to the spacecraft. One way to assess space physics radio data is to construct dynamic spectra which show the time evolution of radio intensity across a large number of frequencies. These data are displayed as images on which the bursts, noise storms, and local plasma noise each display their own characteristic features. Type II Solar radio bursts due to interplanetary shocks are characterized by a fairly slow and steady decrease in frequency over time. Type III bursts due to high-speed beams of electrons drop rapidly and eventually smear or spread out. Finally, the local plasma noise often shows up as a linear feature at fairly low frequencies. Irregularities in emission intensity can challenge automated detection and tracking. However, detection and tracking are important because radio bursts corresponding to disturbances traveling through the interplanetary medium can lead to geomagnetic storms and other hazards should they encounter the Earth. In this paper we analyze dynamic spectra from the Thermal Noise Receiver of the WAVES experiment on board the WIND spacecraft to determine contours of local plasma emission and Type II and III Solar Radio Bursts.