DOI: 10.48322/3tvk-m667
title: Cluster-Tango Wideband (WBD) High Time Resolution Dynamic Spectrogram Plot
title: C4_CG_WBD_GIFPLOT

description: This dataset contains 30 s duration survey spectrogram plots from the WBD instrument on the Cluster spacecraft. The spectrograms are created by 1024 point FFTs and plotted with frequency on the vertical axis, increasing time on the horizontal, and color indicating power spectral density, in relative dB. 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. 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. The time resolution of the data shown in the plots is determined from the WBD instrument mode. 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). Above the spectrogram plot are a line plot panel, followed by four status lines. The line plot panel at the top provides the gain state (0 to 75 dB, in 5 dB steps) of the instrument. The four status lines provide the following information according to the color code in the upper right corner: Data mode - whether from DSN mode (real time telemetry), or from BM2 mode (recorded onboard in Burst Mode 2) as digitally filtered or duty cycled. Antenna - the electric field (Ey or Ez) or the magnetic field (Bx or By) antenna used. Resolution - the data digitization level, which can be 1 bit, 4 bit or 8 bit. Translation - the translation from base frequency of 0 kHz. In the lower right-hand corner are the ephemeris values applicable to the start time of the plot. At the middle right-hand side are given the date and start time of the plot as well as the spacecraft number. The University of Iowa repository maintains two types of high time resolution spectrogram plots in GIF format: a ten minute (PT10M Display Cadence) and a 30 second time span (PT30S Display Cadence). Both types of files provide information on WBD gain and operational mode, the spectral data from one spacecraft, the start date and time and ephemeris data. Overview spectrograms are also available. The availability of these files depends on times of DSN and Pansak Ves ground station telemetry downlinks. 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 Science Archive (https://www.cosmos.esa.int/web/csa/documentation). Details on Cluster WBD Interpretation Issues can be found at http://www-pw.physics.uiowa.edu/cluster/interpretation_issues/interpretation.html 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.