DOI: 10.48322/becc-dm24
title: Cluster Wideband (WBD) Survey Dynamic Spectrogram Plot
title: CM_CG_WBD_SPECPLOT_OVERVIEW_PNG

description: This dataset contains survey spectrogram plots of varying time durations from the WBD Plasma Wave Receivers on the four Cluster spacecraft. Due to the nature of the WBD real-time operations at the DSN, data from all four spacecraft are not always available. The time span of these plots varies based on the time span of the telemetry received in real-time from the DSN and Panska Ves ground stations and can range from 30 minutes to 8 hours, 2 hours being typical. Panels are included in the overview plots for all of the spacecraft for which WBD data are available at any given time. The spectrograms are created by 1024 point FFTs and plotted with frequency in kHz on the vertical axis, increasing time on the horizontal, and color indicating the power spectral density. The AC electric field data are obtained by using one of the two 88m spin plane electric field antennas of the EFW instrument as a sensor. The AC magnetic field data are obtained by using one of the two search coil magnetometers (one in the spin plane, the other along the spin axis) of the STAFF instrument as a sensor. When the data shown in the overview plot are from an electric field antenna, the power spectral density is given in units of V^2/m^2/Hz. When the data shown in the overview plot are the WBD magnetic field measurements, the power spectral density is given in relative dB. The WBD antenna used is marked on the left-hand side of each plot panel, and the spacecraft name and number are provided on the right-hand side of each panel. Below the time labels on the horizontal axis, are the ephemeris values applicable to the times marked on the horizontal axis. The ephemeris values are provided for the spacecraft whose data are shown in the bottom panel of the plot, just above the time axis labels. These ephemeris values are provided only as an indication of the general location of the Cluster quartet within the magnetosphere. Due to varying spacecraft separations, the ephemeris values for the spacecraft shown in the other plot panels may be considerably different from the values given for the spacecraft in the bottom panel. At the very bottom of the page are given the date and start time of the plots. At the top of the page, the WBD mode is noted, along with the FFT length and overlap. The WBD data are obtained in one of three filter bandwidth modes: (1) 9.5 kHz, (2) 19 kHz, or (3) 77 kHz. The minimum frequency of each of these three frequency bands can be shifted up (converted) from the default 0 kHz base frequency by 125.454, 250.908 or 501.816 kHz. There will typically be a separate survey spectrogram plot for each operating mode. The time resolution of the data shown in the plots is determined from the WBD instrument mode and FFT length. The highest time resolution data are sampled at 4.6 microseconds in the time domain, 4.7 milliseconds in the frequency domain (generally the 77 kHz bandwidth mode). The lowest time resolution data are sampled at 36.5 microseconds in the time domain, 37.3 milliseconds in the frequency domain (generally the 9.5 kHz bandwidth mode). When data from multiple spacecraft are shown in the overview plots, the time span in which WBD data are available for each spacecraft may be different. Periods when no data were available will appear white on the overview plots. On the lower right-hand corner of the page, UIowa appears next to the date on which the plot was generated in the format YYMMDD. Please note that during operations in certain magnetospheric regions, the WBD Plasma Wave Receiver may cycle between electric and magnetic field antennas or through the 125.454 kHz, 250.908 kHz, and 501.816 kHz conversion frequencies. When the instrument cycles through different modes, separate ps overview plots are generated for each antenna or conversion frequency used over the entire duration of the operation. In these plots, only data from one mode are shown on each plot, and the data are dilated across the intervals when another mode was used. The modes used and the length of the cycling intervals are provided on the left-hand side of the ps overview plot, along with a note that the plot is not intended for publication. Please contact the WBD PI if you wish to publish or present data from periods with cyclical switching between instrument modes. Higher time resolution spectrograms are also available for each spacecraft separately. These data are presented as ten minute time span and 30 second time span GIF image files. Details on Cluster WBD Interpretation Issues can be found at http://www-pw.physics.uiowa.edu/cluster/interpretation_issues/interpretation.html A list of the status of the WBD instrument on each spacecraft, the telemetry time spans, operating modes and other details are available under Science Data Availability on the University of Iowa Cluster WBD web site at (http://www-pw.physics.uiowa.edu/cluster/) and through the documentation section of the Cluster Active Archive (http://caa.estec.esa.int/caa). For further details on the Cluster WBD data products see Pickett, J.S., et al., "Cluster Wideband Data Products in the Cluster Active Archive" in The Cluster Active Archive, 2010, Springer-Verlag, pp 169-183.