!   $Id: 6209,v 9.1 1995/08/02 17:20:57 pepsa Exp $

Proposal_Information

   Title:               GL140l PHOTOCATHODE GRANULARITY TEST FOR HIGH S/N STABILITY
   Proposal_Category:   CAL/HRS
   Scientific_Category: CALIBRATION
   Cycle:               5


Investigators

   PI_name:             ALFRED B. SCHULTZ
   PI_Institution:      STSCI
   CoI_Name:            STEVE HULBERT
   CoI_Institution:     STSCI

Questions

   Observing_Description:
   Real_Time_Justification:
   Calibration_Justification:
   Additional_Comments: 


Abstract:               CYCLE 5 calibration of photocathode granularity for domains
                        covered by G140L in SSA and LSA.  The signal-to-noise
                        attainable with GHRS in standard ACCUM modes will normally
                        be limited to a few percent by uncalibrated sensitivity
                        variations on the photocathodes.  With prior calibration this
                        limitation can be alleviated.
                        This proposal covers only D1 for which the granularity is
                        to be a severe limitation.
                        A test of high S/N calibration stability is made in ECH-A
                        at 1478 A in SSA , a region where independent
                        GTO/OS observations will obtain high S/N (about 500) in
                        a separate star.
                        Region of photocathode ind. meas. for G140M


Fixed_Targets

   Target_Number:       1
   Target_Name:         BD+75D325
   Alternate_Names:     GSC4380-2196
   Description:         CALIBRATION,FLAT FIELD
   Position:            RA = 8H 10M 49.31S +/- 0.5S,
                        DEC = +74D 57' 57.5" +/- 0.5",
                        PLATE-ID=00LQ
   Equinox:             J2000
   Epoch:               B1983.80
   Rv_or_z:             
   RA_PM:               0.000257
   Dec_PM:              0.007
   Annual_Parallax:     0.0
   Flux:                V=9.54,
                        TYPE=SD0,
                        B-V=-0.36
   Comments:            SPECTROPHOTOMETRIC STANDARD


Visits

Visit_Number:           01
Visit_Requirements:     
    Visit_Comments:  This program maps out the photocathode.  A flat field
                     is obtained by obtaining spectra at different locations
                     on the photocathode.  Visit 1 is to obatin a flat field
                     using the large science aperture with the G140L grating.
On_Hold_Comments:       

   Exposure_number:     10
   Target_Name:         BD+75D325
   Config:              HRS
   Opmode:              ACQ
   Aperture:            2.0
   Sp_Element:          MIRROR-N1
   Wavelength:          
   Optional_Parameters: SEARCH-SIZE=3, BRIGHT=RETURN
   Number_of_iterations:1
   Time_Per_Exposure:   1.8S
   Special_Requirements:ONBOARD ACQ FOR 20-40
   Comments:            STEP_TIME=0.2S

   Exposure_number:     20
   Target_Name:         BD+75D325
   Config:              HRS
   Opmode:              ACCUM
   Aperture:            2.0
   Sp_Element:          G140L
   Wavelength:          1347.0
   Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=5
   Number_of_iterations:1
   Time_Per_Exposure:   108.8S
   Special_Requirements:
   Comments:            MIN EXP TIME = 27.2S
                        Wavelength 1347.0
                        Y Deflection 1494.2

   Exposure_number:     30
   Target_Name:         BD+75D325
   Config:              HRS
   Opmode:              WSCAN
   Aperture:            2.0
   Sp_Element:          G140L
   Wavelength:          1170.0-1690.0
   Optional_Parameters: WAVE-STEP=52, COMB=NO, STEP-PATT=5
   Number_of_iterations:1
   Time_Per_Exposure:   272S
   Special_Requirements:
   Comments:            MIN EXP = 27.2S
                        Check diode response function
                        Wavelength 1170.0-1690.0
                        Y Deflection 1521.3-1440.8

   Exposure_number:     40
   Target_Name:         BD+75D325
   Config:              HRS
   Opmode:              WSCAN
   Aperture:            2.0
   Sp_Element:          G140L
   Wavelength:          1170.0-1690.0
   Optional_Parameters: WAVE-STEP=52, FP-SPLIT=STD, STEP-PATT=5
   Number_of_iterations:1
   Time_Per_Exposure:   1088S
   Special_Requirements: NO SPLIT
   Comments:            MIN EXP TIME = 27.2S
                        Wavelength 1170.0-1690.0
                        Y Deflection 1521.3-1440.8


Visit_Number:           02
Visit_Requirements:     
    Visit_Comments:  Please note that Visits 1 and 2 should be scheduled
                     as close in time as possible.  
                     Visit 2 is to obtain a flat field
                     using the small science aperture with the G140L grating.

On_Hold_Comments:       

   Exposure_number:     10
   Target_Name:         BD+75D325
   Config:              HRS
   Opmode:              ACQ
   Aperture:            2.0
   Sp_Element:          MIRROR-N1
   Wavelength:          
   Optional_Parameters: SEARCH-SIZE=3, BRIGHT=RETURN
   Number_of_iterations:1
   Time_Per_Exposure:   1.8S
   Special_Requirements:ONBOARD ACQ FOR 20
   Comments:            STEP_TIME=0.2S

   Exposure_number:     20
   Target_Name:         BD+75D325
   Config:              HRS
   Opmode:              ACQ/PEAKUP
   Aperture:            0.25
   Sp_Element:          MIRROR-N1
   Wavelength:          
   Optional_Parameters: SEARCH-SIZE=5
   Number_of_iterations:1
   Time_Per_Exposure:   5.0S
   Special_Requirements:ONBOARD ACQ FOR 80-100
   Comments:            STEP_TIME=0.2S

   Exposure_number:     80
   Target_Name:         BD+75D325
   Config:              HRS
   Opmode:              ACCUM
   Aperture:            0.25
   Sp_Element:          G140L
   Wavelength:          1347.0
   Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=5
   Number_of_iterations:2
   Time_Per_Exposure:   108.8S
   Special_Requirements:
   Comments:            MIN EXP TIME = 27.2S
                        Wavelength 1347.0
                        Y Deflection 1494.3

   Exposure_number:     100
   Target_Name:         BD+75D325
   Config:              HRS
   Opmode:              WSCAN
   Aperture:            0.25
   Sp_Element:          G140L
   Wavelength:          1170.0-1690.0
   Optional_Parameters: WAVE-STEP=52, FP-SPLIT=STD, STEP-PATT=5
   Number_of_iterations:1
   Time_Per_Exposure:   1088S
   Special_Requirements: NO SPLIT
   Comments:            MIN EXP. TIME = 27.2S
                        Wavelength 1170.0-1690.0
                        Y Deflection 1521.3-1440.8


Data_Distribution

   Medium:              8MM
   Blocking_Factor:     10
   Ship_To:             PI_Address
   Ship_Via:            UPS
   Recipient_Email: