Ganymede 2

GALILEO PWS GANYMEDE 2 OBSERVATION PLANNING

What's new (9 March)

An overview of the G2 encounter period

And 1-day summaries for greater detail:

Magnetospheric Survey, R > 50 Rj

Spectrum Analyzer Mode:

Antenna: Cycle (toggles between E and B every 18.67 s)

Wideband Mode: (This is mostly irrelevant since little or no wideband data will be obtained in the Magnetospheric Survey--only occasional fill data)

Antenna: E
Mode: 1 (10 kHz)

Magnetospheric Survey, R < 50 Rj

Spectrum Analyzer Mode:

Antenna: Cycle (toggles between E and B every 18.67 s)

Wideband Mode: (This is mostly irrelevant since little or no wideband data will be obtained in the Survey--only occasional fill data and data which is automatically recorded with remote sensing recorded observations)

Antenna: E
Mode: 2 (80 kHz)

Plasma Sheet Crossing

Record for ~60 minutes beginning at about 02:24 on day 255 at a distance of ~ 39.2 Rj.


Record LPW from 96-255/02:31:30 - 02:56:30
Record MPP from        02:56:30 - 03:05:33
Record LPW from        03:03:53 - 03:31:30

Spectrum Analyzer Mode:

Antenna: Cycle (toggles between E and B every 18.67 s)

Wideband Mode:

Antenna: 4 minutes E, followed by 1 minute B (looper)
Mode: 3 (1 kHz)

Playback Strategy:

Return LPW (Golay) wideband data at rate of 4:1 by returning every 4th waveform snapshot. Return 1 minute of MPP based on evaluation of RTS for best (most interesting) interval. Note that this 1 minute is in lieu of or to be split with the MPP playback from the perijove observation. In order to meet degraded downlink capabilities, it is anticipated that the MPP data will not be returned and that only 40 minutes of the 60-minute recording will be played back.

Perijove Magnetic Equator Crossing

This observation includes a magnetic equator crossing (using GSFC04 with plasma sheet crossing) at 10:07:22 and a centrifugal equator crossing at about 10:11:09. In order to meet degraded downlink capabilities, it is anticpated that this observation will be recorded, but not returned at all.

Record for ~45 minutes beginning at ~09:45 on day 251 near 10.9 Rj.


Record LPW from 96-251/09:44:45 - 10:01:57
Record MPP from        10:01:57 - 10:12:04
Record LPW from        10:12:04 - 10:30:15

Spectrum Analyzer Mode:

Antenna: Cycle (toggles between E and B every 18.67 s)

Wideband Mode:

Antenna: 4 minutes E followed by 1 minute B (looper)
Mode: 3 (1 kHz)

Playback Strategy:

Return LPW (Golay) wideband data at a rate of 2:1. Return up to 1 minute of MPP based on analysis of RTS data for most interesting period. Note that this playback of MPP is in lieu of or to be split with the MPP playback associated with the plasma sheet crossing. As noted above, this entire observation may not be returned due to the decreased downlink capabilities.

Ganymede Closest Approach

Record LPW for ~60 minutes beginning at about 18:32 on day 250.


Record LPW from 96-250/18:31:50 - 19:32:30

Spectrum Analyzer Mode:

Antenna: Cycle (toggles between E and B every 18.67 s)

Wideband Mode:

Antenna: Toggle E and B once per 18.67 sec (28 mf) except E when UVS is noisy, then E only (Note: the E/B looper has to be constructed in such a way as to have an integer number of steps per RIM or 2-RIM pair, and must have an integer number of 14-mf steps to assure that the commands are executed on the appropriate (odd or even?) mf--as we did in the Io torus.)
Mode: 3 (1 kHz)

Playback Strategy:

Return LPW (Golay) wideband data at a rate of 2:1 by sending back every other waveform snapshot for the 20 minutes closest to Ganymede. Return LPW (Golay) wideband data for the remaining (more distant) portions of the interval at a rate of 4:1 by sending back every 4th waveform snapshot. In order to meet degraded downlink capabilities, it is anticipated that only 55 minutes of this observation will be returned, and that 4:1 compression of the PWS wideband data will be utilized throughout.

Broadband Kilometric Radiation

Record twelve 30-second intevals at HRW in the 80-kHz mode in order to observe the high spectral and temporal resolution features of broadband kilometric radiation.

Time                Rj      Mag. Lat.
96-245/     23:10   53.6    -12.1 
            23:30   53.5    -13.1
96-246/     00:30   53.3    -13.4
            01:00   53.1    -12.2
            09:00   51.0    -11.5
            09:35   50.9    -13.2
            10:30   50.6    -13.3
            11:00   50.5    -12.6
            19:10   48.2    -12.1
            19:30   48.1    -13.0
            20:30   47.8    -13.2
            21:00   47.7    -11.9

Spectrum Analyzer Mode:

Antenna: Cycle (toggles between E and B every 18.67 sec)

Wideband Mode:

Antenna: E
Mode: 2 (80 kHz)

Playback Strategy:

Use RTS data to determine the best (most likely to include bKOM) observations for playback at 1:1. It would be desirable to return two 30-second observations. In order to meet degraded downlink capabilities, these data may be compressed at 2:1 or 3:1 and the returned data will be limited to 2 Mb.

william-kurth@uiowa.edu