!  File:  1081C.PROP
!  Database:  PEPDB
!  Date:  16-FEB-1994:00:56:25

coverpage:

  title_1:         SATURN RING DYNAMICS
    sci_cat:       SOLAR SYSTEM
    proposal_for:  GTO/HSP
    pi_fname:      ROBERT
    pi_mi:         C.
    pi_lname:      BLESS
    pi_inst:       WISCONSIN, UNIVERSITY OF
    pi_country:    USA
    pi_phone:      608-262-1715
    keywords_1:    SATURN'S RINGS, OCCULTATIONS, RING DYNAMICS
    hours_pri:     22.00
    num_pri:       17
    hsp:           Y
    time_crit:     Y
! end of coverpage

abstract:

    line_1:        Understanding the dynamics of the rings is essential to our eventual
    line_2:        understanding of their origin. Did they form recently or along with Saturn
    line_3:        itself? We propose a series of stellar occultation observations in order to
    line_4:        continue the dynamical investigation of Saturn's rings, at high spatial
    line_5:        resolution, begun by the Voyager spacecraft.
    line_6:        Revision History: Received on RPS 9/1/89;  Added to SCCS 9/5/89
    line_7:        RPSS V7.2 local & remote; fixed up small syntax errors - SALM 9/5/89
    line_8:        Updated for cycle 1 -- amanda bosh (MIT) 28 Sept 89
    line_9:        asb @ MIT 19 Mar 1990:  Updated cycle 1 targets;  SPATIAL SCANs, GUID TOL
    line_10:       changes etc. - asb@MIT 23May90; Small logic errors fixed--BJW 7/9/90;
    line_11:       revised changes to SEQ--BJW 7/31/90; Change cycle 0 to cycle 8 on line
    line_12:       110.040--BJW 11/28/90; Changes to observations/targets--amanda; Split
    line_13:       proposal by cycle--BJW 5/2/91; Added reference for target positions--BJW
    line_14:       7/18/91;

!
! end of abstract

general_form_proposers:

  lname:           ROBINSON
    fname:         EDWARD
    mi:            L.
    inst:          TEXAS, UNIVERSITY OF
    country:       USA

!

  lname:           BLESS
    fname:         ROBERT
    mi:            C.
    inst:          WISCONSIN, UNIVERSITY OF
    country:       USA

!

  lname:           VAN CITTERS
    fname:         G.
    mi:            W.
    inst:          NATIONAL SCIENCE FOUNDATION
    country:       USA

!

  lname:           DOLAN
    fname:         JOSEPH
    mi:            F.
    inst:          NASA, GODDARD SPACE FLIGHT CENTER
    country:       USA

!

  lname:           WHITE
    fname:         RICHARD
    mi:            L.
    inst:          SPACE TELESCOPE SCIENCE INSTITUTE
    country:       USA

!

  lname:           ELLIOT
    fname:         JAMES
    mi:            L.
    inst:          MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    country:       USA

!
! end of general_form_proposers block

general_form_text:

  question:        3
    section:       1
    line_1:        We plan to use the ST orbit parameters and catalogs of the objects of interest
    line_2:        to identify those occultations of sufficient signal-to-noise ratio to achieve
    line_3:        the goals outlined in Section 2. Each observation will require (i) external
    line_4:        "darks", taken on a dark region of sky as a calibration source, (ii) a scan
    line_5:        of about 30-40 arcseconds along the track that the object will follow relative
    line_6:        to Saturn's rings, (iii) a set of two sequential onboard acquisitions; and (iv)
    line_7:        a time series run on the object with whatever filter-aperture combination that
    line_8:        is chosen for the observation. For some occultations to be observed in the far
    line_9:        uv, prior multi-filter photometry of the object will be necessary in order to
    line_10:       determine the most appropriate filter to use for the occultation. The default
    line_11:       filter set is F750W/F320N. For now, we shall assume that the calibration and
    line_12:       observation time will average about 3 hours per occultation observed. About ten
    line_13:       occultations would be required to achieve our goals of establishing orbits for
    line_14:       the ringlets and other sharp-edged features of the system. For at least a few
    line_15:       events, it would be important to observe occultations by the same features on
    line_16:       both sides of the planet.
    line_17:       All cycles.

!

  question:        4
    section:       1
    line_1:        We can achieve a much better signal-to-noise ratio for Saturn ring occultations
    line_2:        than would be possible from the ground because of (i) the absence of
    line_3:        scintillation noise, which has strong components at frequencies corresponding
    line_4:        to the occultation timescales, and (ii) our ability to reject background light
    line_5:        from the rings themselves by employing small focal plane apertures.

!

  question:        5
    section:       1
    line_1:        Acquisition of the star near Saturn may prove to be difficult.

!

  question:        6
    section:       1
    line_1:        A prior scan over 30-40 arcseconds is needed to map the scattered light field,
    line_2:        which is needed for the data reduction.

!

  question:        7
    section:       1
    line_1:        Data will be reduced and analyzed at MIT with the DEC 5000 belonging to the
    line_2:        planetary astronomy group.

!

  question:        8
    section:       1
    line_1:        SV test HSP09A must be completed before these observations
    line_2:        are made because the exact observation sequence may need
    line_3:        to be modified depending on the results of the SV test.

!

  question:        10
    section:       1
    line_1:        Data reduction and analysis will be supported on computer
    line_2:        facilities at MIT.

!

  question:        13
    section:       1
    line_1:        Observations of a series of stellar occultations by Saturn's rings with the HSP
    line_2:        (or perhaps FOS) can provide precise orbits of ringlets, other sharp features,
    line_3:        waves, and other phenomena in the Saturn system at high spatial resolution.
    line_4:        From these data further understanding of the present dynamical state of the
    line_5:        ring system can be gained. This understanding should improve our knowledge of
    line_6:        the past history and conditions of formation of the rings.

!
!end of general form text

general_form_address:

  lname:           BLESS
    fname:         ROBERT
    mi:            C.
    category:      PI
    inst:          UNIVERSITY OF WISCONSIN
    addr_1:        DEPARTMENT OF ASTRONOMY
    city:          MADISON
    state:         WI
    zip:           53706
    country:       USA
    phone:         608-262-1715

!

  lname:           ELLIOT
    fname:         JAMES
    mi:            L.
    category:      CON
    inst:          MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    addr_1:        BLDG. 54-422
    city:          CAMBRIDGE
    state:         MA
    zip:           02139
    country:       USA
    phone:         617-253-6308
    telex:         921473 MIT CAM

!
! end of general_form_address records

fixed_targets:

    targnum:       11
    name_1:        GSC6323-01396
    descr_1:       STAR TO BE OCCULTED BY SATURN.
    descr_2:       CLOSE APPROACH AT 2-OCT-91:04:57
    pos_1:         PLATE-ID = 04O8,
    pos_2:         RA = 20H 10M 30.352S +/- 0.4",
    pos_3:         DEC = -20D 36' 47.593" +/- 0.4",
    equinox:       J2000
    acqpr_1:       BKG
    comment_1:     COORDS FROM
    comment_2:     GUIDE STAR CATALOG
    comment_3:     SOLAR ELONG E113D
    fluxnum_1:     1
    fluxval_1:     V = 12.47 +/- 0.59

!

    targnum:       12
    name_1:        GSC6327-00161
    descr_1:       OFFSET TARGET FOR GSC6323-01396
    pos_1:         PLATE-ID = 04O8,
    pos_2:         RA = 20H 10M 32.868S +/- 0.4",
    pos_3:         DEC = -20D 38' 14.964" +/- 0.4",
    equinox:       J2000
    acqpr_1:       BKG
    comment_1:     COORDS FROM
    comment_2:     GUIDE STAR CATALOG
    comment_3:     SOLAR ELONG E113D
    fluxnum_1:     1
    fluxval_1:     V = 15.50 +/- 0.61

!

    targnum:       13
    name_1:        DARK-PMT
    pos_1:         RA = 16H 27M 11.0S +/- 0.1S,
    pos_2:         DEC = -24D 19' 14.0" +/- 0.1S,
    equinox:       J2000
    comment_1:     DARK PORTION OF THE SKY FOR
    comment_2:     PMT DARK MEASUREMENT

!
! end of fixed targets

solar_system_targets:

  targnum:         18
    name_1:        SATURN-BACKGROUND
    descr_1:       OFFSET SATURN
    lev1_1:        STD = SATURN
    lev2_1:        TYPE = POS_ANGLE,
    lev2_2:        RAD = 11.5,
    lev2_3:        ANG = 219.7,
    lev2_4:        REF = NORTH
    comment_1:     FOR USE IN A SCAN OF
    comment_2:     BACKGROUND LEVELS ALONG
    comment_3:     THE PATH OF THE OCCULTED STAR
    fluxnum_1:     1
    fluxval_1:     V = 0.7 +/- 0.5

!
! end of solar system targets

! No generic target records found

exposure_logsheet:

    linenum:       4.000
    sequence_1:    DEFINE
    sequence_2:    ONBRD-ACQ
    targname:      #
    config:        HSP/VIS
    opmode:        ACQ
    num_exp:       1
    time_per_exp:  120S
    fluxnum_1:     1
    priority:      1
    req_1:         GUID TOL 0.007";
    comment_1:     USE FINE LOCK FOR OFFSET TARGET ACQ
    comment_2:     IF BRIGHT ENOUGH GUIDE STARS CAN BE
    comment_3:     FOUND.  IF NOT, COARSE TRACK IS
    comment_4:     ACCEPTABLE.

!

    linenum:       5.000
    sequence_1:    DEFINE
    sequence_2:    EXT-DARK
    targname:      #
    config:        HSP/PMT/VIS
    opmode:        SPLIT
    aperture:      1.0
    sp_element:    F750W/F320N
    num_exp:       1
    time_per_exp:  5M
    fluxnum_1:     1
    priority:      1
    param_1:       SAMPLE-TIME=0.15
    param_2:       DATA-FORMAT = ALL,
    param_3:       PRECISION = HIGH,
    param_4:       ANALOG-SCALE = 1000,
    req_1:         GUID TOL 0.02";
    comment_1:     EXTERNAL STANDARD CALIBRATION.
    comment_2:     USE COARSE TRACK FOR TRACKING.
    comment_3:     HIGH ACCURACY NOT NEEDED, WANT
    comment_4:     TO SAVE TIME.

!

    linenum:       6.000
    sequence_1:    DEFINE
    sequence_2:    BACK-SCAN
    targname:      #
    config:        HSP/PMT/VIS
    opmode:        SPLIT
    aperture:      1.0
    sp_element:    F750W/F320N
    num_exp:       1
    time_per_exp:  1S
    fluxnum_1:     1
    priority:      1
    param_1:       #
    param_2:       DATA-FORMAT = ALL,
    param_3:       ANALOG-SCALE = 1000,
    param_4:       PRECISION = HIGH,
    req_1:         SPATIAL SCAN SINGLE-EXP;
    req_2:         GUID TOL 0.007";
    comment_1:     USE FINE LOCK FOR OFFSET TARGET ACQ
    comment_2:     IF BRIGHT ENOUGH GUIDE STARS CAN BE
    comment_3:     FOUND.  IF NOT, COARSE TRACK IS
    comment_4:     ACCEPTABLE.

!

    linenum:       7.000
    sequence_1:    DEFINE
    sequence_2:    RING-OCC
    targname:      #
    config:        HSP/PMT/VIS
    opmode:        SPLIT
    aperture:      1.0
    sp_element:    F750W/F320N
    num_exp:       1
    time_per_exp:  1M
    fluxnum_1:     1
    priority:      1
    param_1:       SAMPLE-TIME=0.15,
    param_2:       PRECISION=HIGH,
    param_3:       DATA-FORMAT=ALL,
    param_4:       ANALOG-SCALE = 1000,
    req_1:         CRIT OBS;
    req_2:         GUID TOL 0.007";
    comment_1:     USE FINE LOCK FOR OFFSET TARGET ACQ
    comment_2:     IF BRIGHT ENOUGH GUIDE STARS CAN BE
    comment_3:     FOUND.  IF NOT, COARSE TRACK IS
    comment_4:     ACCEPTABLE.  HSP09A (SV TEST) MUST
    comment_5:     BE COMPLETED SUCCESSFULLY BEFORE
    comment_6:     THESE OBSERVATIONS.

!

    linenum:       110.000
    sequence_1:    USE
    sequence_2:    EXT-DARK
    targname:      DARK-PMT
    req_1:         GROUP 110.000 - 110.113 WITHIN 3D;
    req_2:         CYCLE 0/110.000 - 110.280;

!

    linenum:       110.010
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      SATURN-BACKGROUND
    time_per_exp:  X174
    param_1:       SAMPLE-TIME = 0.01,
    req_1:         SEQ 110.01 - 110.03;
    req_2:         GROUP 110.01 - 110.04 WITHIN 1D;

!

    linenum:       110.020
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      SATURN-BACKGROUND
    time_per_exp:  X868
    param_1:       SAMPLE-TIME = 0.15,

!

    linenum:       110.030
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      SATURN-BACKGROUND
    time_per_exp:  X174
    param_1:       SAMPLE-TIME = 0.01,

!

    linenum:       110.040
    sequence_1:    USE
    sequence_2:    ONBRD-ACQ
    targname:      GSC6327-00161
    req_1:         ONBOARD ACQ FOR 110.101 - 110.113;
    req_2:         SEQ 110.04 - 110.113 NO GAP;
    comment_1:     THIS OCCULTATION OCCURS OVER SEVEN
    comment_2:     DAYS.  IT IS BEING BROKEN INTO SEVERAL
    comment_3:     PARTS, AND ONLY CLASSICAL RING
    comment_4:     DATA WILL BE COLLECTED.

!

    linenum:       110.101
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X39
    req_1:         AT 2-OCT-91:19:30  +/- 30M;
    comment_1:     END EXPOSURE AT 3-OCT-91:15:00.
    comment_2:     TIME_PER_EXP IS SHORTER THAN THAT
    comment_3:     CALCULATED FROM START-STOP TIMES
    comment_4:     TO ACCOUNT FOR EARTH OCCULTATIONS.

!

    linenum:       110.102
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X40

!

    linenum:       110.103
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X17

!

    linenum:       110.104
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X18

!

    linenum:       110.105
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X22

!

    linenum:       110.106
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X28

!

    linenum:       110.107
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X34

!

    linenum:       110.108
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X40

!

    linenum:       110.109
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X40

!

    linenum:       110.110
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X40

!

    linenum:       110.111
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X40

!

    linenum:       110.112
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X40

!

    linenum:       110.113
    sequence_1:    USE
    sequence_2:    RING-OCC
    targname:      GSC6323-01396
    time_per_exp:  X40

!

    linenum:       110.260
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      SATURN-BACKGROUND
    time_per_exp:  X174
    param_1:       SAMPLE-TIME = 0.01,
    req_1:         SEQ 110.26 - 110.28;
    req_2:         GROUP 110.101 - 110.28 WITHIN 1D;

!

    linenum:       110.270
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      SATURN-BACKGROUND
    time_per_exp:  X868
    param_1:       SAMPLE-TIME = 0.15,

!

    linenum:       110.280
    sequence_1:    USE
    sequence_2:    BACK-SCAN
    targname:      SATURN-BACKGROUND
    time_per_exp:  X174
    param_1:       SAMPLE-TIME = 0.01,

!
! end of exposure logsheet

scan_data:

    line_list:     110.01, 110.03, 110.26, 110.28
    fgs_scan:
    cont_dwell:    C
    dwell_pnts:    0
    dwell_secs:       0.00
    scan_width:       0.0000
    scan_length:     34.7000
    sides_angle:    90.0000
    number_lines:  1
    scan_rate:       0.2000
    first_line_pa:  70.3000
    scan_frame:    CEL
    len_offset:    0.
    wid_offset:    0.

!

    line_list:     110.02, 110.27
    fgs_scan:
    cont_dwell:    C
    dwell_pnts:    0
    dwell_secs:       0.00
    scan_width:       3.0000
    scan_length:     34.7000
    sides_angle:    90.0000
    number_lines:  5
    scan_rate:       0.2000
    first_line_pa:  70.3000
    scan_frame:    CEL
    len_offset:    0.
    wid_offset:    1.5

!
! end of scan data