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GO JUPITER PWS EDITED EDR 1KHZ WAVEFORM RECEIVER V1.0 (PDS)

NSSDCA ID: PSFP-00299

Availability: Archived at NSSDC, accessible from elsewhere

Description

This description was generated automatically using input from the Planetary Data System. This data set includes wideband waveform measurements from the Galileo plasma wave receiver obtained during Jupiter orbital operations. These data were obtained during selected observation periods near perijove, satellite encounters and other select times. These measurements are electric waveforms obtained by rapidly sampling the potential at the input to the receiver from the electric dipole antenna. The sample rates are 201,600/s, 25,200/s, or 3,150/s taken through bandpass filters of 80, 10, or 1 kHz, respectively. Each sample is a 4-bit measurement after an automatic gain control (AGC) amplifier designed to keep the signal amplitude in a range commensurate with the optimal analog-to-digital converter dynamic range with a time constant of about 500 msec. As such, the measurements are not absolutely calibrated, although it is possible to determine the approximate AGC gain from a digital performance parameter available every 2.667 seconds, assuming the signal amplitude does not vary appreciably over the 2.667 second interval. Alternately, the sweep frequency receiver (low rate) portion of the instrument can be used to determine the absolute amplitude of waves. In many cases, the waveform data are used without any calibration for the purposes of identifying characteristic frequencies of the plasma via resonances or cutoffs, observing discrete emissions such as chorus or whistlers, or looking at the detailed form of the waveforms. In general, the waveform samples are not continuous over long time periods due to the limited telemetry capability of the Galileo data system and limits on the bandwidth available to the PWS instrument. Instead, sequences of contiguous samples are collected for up to about 67 msec followed by a gap. The number of consecutive samples between gaps is determined by the telemetry format and the bandwidth (instrument mode). Details of the timing, number of consecutive samples in a series, and the effective duty cycle are described in the inst.cat, rowpfx.fmt, and edrhdr.fmt files included with the data set. The data are formatted in files covering no more than 1 RIM (60.667 s) each up to 91 data records, with a record containing 10 or 80 blocks of contiguous waveform samples. The data in any one file are from only a single combination of instrument mode (waveform) and telemetry format, however, the antenna can change within a file; this is noted in the record header information, but is only updated every 2.667 sec, hence, may not be accurate less than 2.667 seconds after a real antenna change. Since the instrument mode information is also updated only once per 2.667 seconds, the last data in a record (less than 2.667 seconds) may actually be in a different mode. The typical uses of the waveform data are to (1) display the waveform of plasma wave and other signals such as dust impacts, and (2) as highly detailed (in time and frequency) spectra through the use of Fourier transforms. To avoid artifacts, we suggest not transforming over the gaps but limiting the input to the Fourier transform to a single contiguous series of samples. Spectra from individual waveform series can be stacked in order to generate frequency-time dynamic spectrograms. This data set is highly discontinuous in time. Because of the severe limitations in the downlink capability of the Galileo spacecraft, LPW rate data were recorded only for targeted observations. Most of these data were acquired near the Galilean moons, although selected observations were made in various locations around the magnetosphere. Table 1 below provides a listing of the start and stop times of the recorded data segments. Even within these time intervals, the data are discontinuous. Data are acquired by using both the electric field and magnetic field antennas. The PDS labels provided contain information about which antenna was used to to generate the data in each file. Most observations were recorded in the LPW tape format with the instrument configured into the PWH5 data format. During the G2 and G7 orbits data were recorded at higher tape speeds in the PWH3 format. ---------------------------------------------------------TABLE 1 ---------------------------------------------------------Start Telemetry PWS Orb Obs-ID* Date Time Range mode format ---------------------------------------------------------J00 IO 1995/12/07 14:52 - 18:26 LPW PWH5 J00 PJOV 1995/12/07 23:25 - 23:56 LPW PWH5 G02 PSX 1996/09/11 02:55 - 02:56 MPP PWH3 C03 TAR 1996/11/05 07:04 - 07:44 LPW PWH5 G07 PSX 1997/03/30 18:50 - 19:35 LPW PWH5 G07 1997/04/01 13:00 - 13:02 MPP PWH3 C09 DSK1 1997/07/04 14:09 - 16:08 LPW PWH5 C09 DSK2 1997/07/14 10:03 - 10:49 LPW PWH5 C09 DSK3 1997/07/23 13:11 - 13:57 LPW PWH5 C09 APJ 1997/08/07 11:06 - 12:38 LPW PWH5 C09 DAWN 1997/08/23 14:07 - 16:09 LPW PWH5 C10 EQX 1997/09/18 22:34 - 23:31 LPW PWH5 E12 EUR 1997/12/16 11:42 - 12:28 LPW PWH5 C21 PJOV 1999/07/01 23:52 - 01:48 LPW PWH5 C23 PJOV 1999/09/14 14:36 - 21:28 LPW PWH5 I24 IO 1999-10-11 04:17 - 04:47 LPW PWH5 I31 IO 2001-08-06 04:25 - 05:29 LPW PWH5 I32 IO 2001-10-16 01:07 - 01:38 LPW PWH5 * The ID element is derived from the SEF identifier for the recorded observation. The recording identifiers translate to: IO, GAN, EUR, CALL - satellites PSX - plasma sheet crossing TAR - trans-auroral region QRS - quarter rotation survey DSK - dusk side of orbit C9 DAWN - dawn side of orbit C9 APJ - apojove TOR - Io torus EQX - magnetic equator crossing PJOV - perijove RAMP - outer torus These designations were defined by the sequence team.

Alternate Names

  • GO-J-PWS-2-EDR-WAVEFORM-1KHZ-V1.0

Discipline

  • Planetary Science: Fields and Particles

Additional Information

Spacecraft

Experiments

Questions and comments about this data collection can be directed to: Dr. Edwin V. Bell, II

 

Personnel

NameRoleOriginal AffiliationE-mail
Prof. Donald A. GurnettData ProviderUniversity of Iowa
Dr. William S. KurthGeneral ContactUniversity of Iowawsk@space.physics.uiowa.edu
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