Data Set Overview : This data set consists of electric field spectrum analyzer data from the Voyager 2 Plasma Wave Subsystem obtained during the entire mission. Data after 2019-01-02 will be added to the archive on subsequent volumes. The data set encompasses all spectrum analyzer observations obtained in the cruise mission phases before, between, and after the Jupiter and Saturn encounter phases as well as those obtained during the two encounter phases. The Voyager 2 spacecraft travels from Earth to beyond 75 AU over the course of this data set. To provide some guidance on when some key events occurred during the mission, the following table is provided. Date Event 1977-08-20 Launch 1979-07-02 First inbound bow shock crossing at Jupiter 1979-08-03 Last outbound bow shock crossing at Jupiter 1981-08-24 First inbound bow shock crossing at Saturn 1981-08-31 Last outbound bow shock crossing at Saturn 1982-04-26 10 AU 1983-08-30 Onset of first major LF heliospheric radio event 1986-01-24 First inbound bow shock crossing at Uranus 1986-01-29 Last outbound bow shock crossing at Uranus 1986-05-26 20 AU 1989-08-07 30 AU 1989-08-24 First inbound bow shock crossing at Neptune 1989-08-28 Last outbound bow shock crossing at Neptune 1992-07-06 Onset of second major LF heliospheric radio event 1993-05-08 40 AU 1996-10-10 50 AU 2000-01-27 60 AU 2002-11-01 Onset of third major LF heliospheric radio event 2003-04-21 70 AU 2006-07-01 80 AU 2007-08-31 Termination shock crossing 2009-09-03 90 AU 2012-11-04 100 AU 2016-01-01 110 AU Data Sampling : This data set consists of average and peak wave electric field intensities accumulated over 1-hour intervals from the Voyager 2 Plasma Wave Receiver spectrum analyzer obtained during the entire mission. For each 1-hour time interval squares of the calibrated electric field measurements obtained during each hour-long interval in each of the 16 spectrum analyzer channels are summed and then divided by the number of measurements. The square root of the resulting value is obtained and stored as the average electric field strength for the respective channel. During the same hour-long interval, the maximum electric field strength acquired in each of the 16 channels is also recorded and stored as the peak electric field strength for the respective channel. Hence, for each hour, an average and peak electric field spectrum from 10 Hz to 56.2 kHz is obtained. The 16 spectrum analyzer channels have center frequencies that range from 10 Hertz to 56.2 kiloHertz and are logarithmically spaced in frequency, four channels per decade. The time associated with each peak and average spectrum is the time of the beginning of the averaging interval. Given variations in the sweep rate of the instrument (from a minimum of 4 seconds/sweep to a maximum of 96 seconds/sweep) the maximum number of samples in an hour-long interval can range from 900 to 38. Data gaps within the interval can further reduce the number of samples. During data gaps where complete spectra are missing, no entries exist in the file, that is, the gaps are not zero-filled or tagged in any other way. Data Processing : The spectrum analyzer data are a continuous (where data are available) low resolution data set which provides wave intensity as a function of frequency (16 log-spaced channels) and time (one spectrum per time intervals ranging from 4 seconds to 96 seconds in the full-resolution data set, depending on telemetry mode.) This data set includes one-hour average and peak values for each channel. The data are typically plotted as amplitude vs. time for one or more of the channels in a strip-chart like display, or can be displayed as a frequency-time spectrogram using a gray- or color-bar to indicate amplitude. With only sixteen channels, it is usually best to stretch the frequency axis by interpolating from one frequency channel to the next either linearly or with a spline fit. One must be aware if the frequency axis is stretched that more resolution may be implied than is really present. The measurements provided in the average and peak electric field spectra included in this data set are in units of electric field (volts/meter). Spectral density units may be obtained by dividing the square of the electric field value by the nominal frequency bandwidth of the corresponding spectrum analyzer channel. specdens : (efield(ichan))**2 / bandwidth(ichan) Finally, power flux may be obtained by dividing the spectral density by the impedance of free space in ohms: pwrflux : (efield(ichan))**2 / bandwidth(ichan) / 376.73 The center frequencies and bandwidths of each PWS spectrum analyzer channel for each Voyager spacecraft are given below: VOYAGER 2 PWS SPECTRUM ANALYZER Voyager-2 Channel Center Frequency Bandwidth 1 10.0 Hz 2.16 Hz 2 17.8 Hz 3.58 Hz 3 31.1 Hz 4.50 Hz 4 56.2 Hz 10.7 Hz 5 100. Hz 13.8 Hz 6 178. Hz 28.8 Hz 7 311. Hz 39.8 Hz 8 562. Hz 75.9 Hz 9 1.00 kHz 75.9 Hz 10 1.78 kHz 151. Hz 11 3.11 kHz 324. Hz 12 5.62 kHz 513. Hz 13 10.0 kHz 832. Hz 14 17.8 kHz 1260 Hz 15 31.1 kHz 2400 Hz 16 56.2 kHz 3800 Hz A failure in the Voyager 2 Flight Data System which occurred about 3 months after launch has adversely affected the calibration of PWS channels 9 through 16. Details of this algorithm may be found in the associated full-resolution description file FULL1_DS.CAT. All suggested data correction steps outlined in the Data Processing section of that file have been applied to the input values prior to calculating the averages and peaks for this reducted resolution dataset. In an attempt to remove many of the noise spikes caused by telemetry bit errors, raw data numbers are compared to the maximum thresholds given in: DATA/HOUR2/FILTER.CSV have been eliminated from the average. Data numbers are compared to the threshold *after* any data corrections. Near planetary encounters raw values were not subject to elimiation when exceeding maximum threshold values. This is represented by using the maximum possible 8-bit value, 255 as the cutoff. Threshold filter values may be changed in the future. Additional information about this data set and the instrument which produced it can be found elsewhere in this catalog. A complete instrument description can be found in [SCARF&GURNETT1977]. Data : The average and peak spectrum analyzer data are a continuous (where data are available) low resolution data set which provides wave intensity as a function of frequency (16 log-spaced channels) and time (one spectrum per hour). Each sample is a floating point electric field strength in units of volts/meter. Ancillary Data : None Coordinates : The electric dipole antenna detects electric fields in a dipole pattern with peak sensitivity parallel to the spacecraft x-axis. However, no attempt has been made to correlate the measured field to any particular direction such as the local magnetic field or direction to a planet. This is because the spacecraft usually remains in a 3-axis stabilized orientation almost continuously. Furthermore, even during the rare times when the spacecraft is turned, the hour-long averages in this data set would almost completely mask any modulation caused by the rotating dipole antenna pattern.

Overview : This data set includes all available spectrum analyzer data acquired during the Voyager 2 mission to date. The data set near planetary encounters has been cleaned prior to averaging for periodic noise spikes due to a stepper motor operating on the LECP and a modulated grid within the PLS. Other spikes of noise below 1 kiloHertz due to the operation of attitude control thrusters have not been removed. Telemetry errors appear in the full resolution data set as randomly-occurring spikes over the entire frequency range. No attempt has been made to remove such spikes because of the difficulty of differentiating between them and valid data, i.e. real bursts of wave activity. The spikes, therefore, can adversely affect the averaged values. The 17.8-Hz channel is sometimes contaminated by interference from the PRA instrument, depending on that instrument's mode. This interference is at a relatively constant level. A failure in the Voyager 2 flight data system on September 24, 1977 has decreased the sensitivity and the calibration accuracy of the upper 8 spectrum analyzer channels (i.e. 1 kiloHertz and higher). One aspect of this failure is that voltages on other inputs to a multiplexer shared by the PWS upper 8 channels can affect the PWS data. Hence, if all 8 upper channels move up and down together, it is likely this is a side effect of the failure and not a real effect in the PWS data. An intermittent failure appeared in the Voyager 2 17.8 Hz channel beginning on November 6, 1995. The channel now exhibits three states. In the original failed state, the channel becomes very noisy, outputting an abnormally large signal. In a second failed state, the output goes to zero. However, for the majority of the time since the failure, the channel outputs credible measurements in the correct amplitude range. Beginning in May 2001 the Voyager 2 wideband receiver began to display degraded operation and by September of 2002, the receiver showed virtually no response. Attempts to playback wideband data from Voyager 2 have ceased. Review : This archival data set was examined by a peer review panel prior to its acceptance by the Planetary Data System (PDS). The peer review was conducted in accordance with PDS procedures. Prior to creation of the final version of the archival data set, key elements of the archive were distributed for preliminary review. These included electronic versions of example PDS labels, CATALOG files, and Software Interface Specifications. These materials were distributed to PDS personnel, the experiment investigator, and others, as appropriate.