Scattered Light Background Monitor

Principal: James Muzerolle
Deputy: Karl Gordon, Dave Frayer, Nanyao
Data Monkey(s):
Priority: Necessary
Downlink Priority: Normal
Analysis Time: 24 hours
Last Updated:


Objective

Monitor background counts at 24, 70, and 160 µm from a set of darks during each campaign, tracking the cool-down of the telescope.

Description

Telescope should be pointed at the default dark position 2 (CVZ-south, 6:16:40 -60:48:59 2000). Acquire dark measurements for 24, 70, and 160 µm using the standard dark IERs.

Data Collected

Darks will be obtained using the standard dark IERs. For the 24 and 160 µm arrays, 35 DCEs will be acquired at 10 second exposure times. A total of 70 DCEs will be acquired for the 70 µm array, 35 at each of the two dark positions.

// EXP_WRITER_VERSION=630
// ****************************************************************************
//
// Creation Date: Mon Feb 10 21:37:00 PST 2003
//
// Expansion File: /epi02/mipsier/V652/wk56e/mips_ier950.exp
//  
//
// ****************************************************************************
//
// 
// Keyword Section
// 
IERID                         0x000000000000                          // IER Identifier
IERType                       MIPS                                    // Type of IET
IERVersion                    6.5.2 Final                             // Spotier Version
IERTitle                      'mip_ier950'                            // Title of IER
Target                        'mips_ier950'                           // Target Name
IERTargetType                 Fixed                                   // Target type of IER
Ra                            17:15:50.00000                          // Target RA
Dec                           +65:25:25.4000                          // Target DEC
NaifId                                                                // NaifId for this IER
TotalExposureTime             1098.89088                              // seconds
TotalExecutionTime            1413.3                                  // seconds
TotalSlewTime                 0.0                                     // seconds
TotalSettlingTime             0.0                                     // seconds
Slew Tax                      0.0                                     // seconds
Special Overhead              0.0                                     // seconds
TotalUplinkLoad               573                                     // bytes
TotalCommandStorageLoad       182                                     // bytes
TotalStringStorageLoad        199                                     // bytes
TotalNumberOfInstructions     52                                      // Instruction count
TotalDownlinkLoad             29861154                                // bytes
CommandDCE                    353                                     // Number of DCEs commanded
TotalDCE                      1059                                    // Number of DCEs in database
VisibilityRadius              0.0                                     // Visibility radius for this IER
Expedited                     'false'                                 // Expedited for downlink processing
StartTime                     2004-181T19:07:51.933                   // StartTime for this IER
BodyStartTime                 2004-181T19:07:51.933                   // BodyStartTime for this IER
Author                        'A.Noriega-Crespo'                      // Name of IER author
Version                       'V2.1'                                  // Version number (set by Author)
Purpose                       'Scattered Background '                 // Purpose of this IER
Notes                         'M.Rieke,Chad,KGordon_input'            // General notes
//
// Expansion Section
//
00:00:00.000 START                                          // Meta command indicates start of expansion
00:00:00.000 VML_EVAL                                       // Place holder for VML EVAL construct
                             GV_ACTIVE_AORID_FLAGS          // global variable name
                             0x0000                         // value or expression
00:00:00.100 VML_EVAL                                       // Place holder for VML EVAL construct
                             GV_ACTIVE_AORID_KEY            // global variable name
                             0x00000000                     // value or expression
00:00:00.200 VML_EVAL                                       // Place holder for VML EVAL construct
                             GV_AOR_START_TIME              // global variable name
                             NOW                            // value or expression
00:00:00.300 INITIAL_SLEW_FIXED                             // BLOCK: SSC slew to fixed science target
                             99                             // FOVNUM
                             932250000                      // RA
                             235525400                      // DEC
                             0                              // RCA
                             0                              // DELTA_EAST
                             0                              // DELTA_NORTH
                             0                              // DELTA_V
                             0                              // DELTA_W
                             4                              // EXPOSURE_LENGTH
                             200                            // SIGMA
                             0.0                            // PCRS_DET_SETTLE_TIME_1
// SLEW MODEL: delT - 0.30000000000000004
// SLEW MODEL: raUC - 932250000
// SLEW MODEL: decUC - 235525400
// SLEW MODEL: pmRa - 0.0
// SLEW MODEL: pmDec - 0.0
// SLEW MODEL: startTime - 2004-181T19:07:51.933
00:00:08.400 MIPS_MOBS_PHOTO                                // BLOCK: SSC change MIPS state from observe to photo
                             0x003c99a0                     // OPERCESTATE
// COMMENT: 24um Dark position
00:00:13.600 CESCANPOS                                      //
                             101                            // posindex
                             'MIPS'                         // csmode
// COMMENT: Initialize the Instrument
00:00:15.600 CEGERSTCON                                     //
                             10                             // ge160rst : 4 Ge frames
                             127                            // ge70rst : 4 Ge frames
                             4                              // rstdelay : 1 Ge frame
                             'MIPS'                         // csmode
00:00:16.600 CEGESTIM                                       //
                             'AUTO'                         // stim_mode
                             63                             // stimcycle : DCEs
                             'BOTHOFF'                      // ge160fld
                             'BOTHOFF'                      // ge70fld
                             'BOTHOFF'                      // ge70flat
                             10                             // ge160dur : Two Ge Frames
                             10                             // ge70dur : Two Ge Frames
                             'MIPS'                         // csmode
00:00:17.600 CESCANCON                                      //
                             'CHOP'                         // scanmode
                             'FWD'                          // rampdir
                             0                              // scanpos2 : 18.901 arcsec
                             2048                           // relpos1 : 2.3626 arcsec
                             2048                           // relpos2 : 2.3626 arcsec
                             0                              // stepoffset : 2.3626 arcsec
                             511                            // rampslope : 0.1 msec/2.3626 arcsec
                             'MIPS'                         // csmode
// COMMENT: 3 sec  5 x 10 DCEs
00:00:18.600 CEMIPSUR                                       //
                             0x0000                         // aorid_flags
                             0x00000000                     // aorid_key
                             0                              // expid
                             'NO_COADD'                     // coadd
                             2                              // framenum
                             10                             // numdce : DCEs
                             'MIPS'                         // csmode
// EXPOSURE_INFO: Exposure_Type = 'd1'
00:01:00.600 CEMIPSUR                                       //
                             0x0000                         // aorid_flags
                             0x00000000                     // aorid_key
                             1                              // expid
                             'NO_COADD'                     // coadd
                             2                              // framenum
                             10                             // numdce : DCEs
                             'MIPS'                         // csmode
// EXPOSURE_INFO: Exposure_Type = 'd1'
00:01:42.600 CEMIPSUR                                       //
                             0x0000                         // aorid_flags
                             0x00000000                     // aorid_key
                             2                              // expid
                             'NO_COADD'                     // coadd
                             2                              // framenum
                             10                             // numdce : DCEs
                             'MIPS'                         // csmode
// EXPOSURE_INFO: Exposure_Type = 'd1'
00:02:24.600 CEMIPSUR                                       //
                             0x0000                         // aorid_flags
                             0x00000000                     // aorid_key
                             3                              // expid
                             'NO_COADD'                     // coadd
                             2                              // framenum
                             10                             // numdce : DCEs
                             'MIPS'                         // csmode
// EXPOSURE_INFO: Exposure_Type = 'd1'
00:03:06.600 CEMIPSUR                                       //
                             0x0000                         // aorid_flags
                             0x00000000                     // aorid_key
                             4                              // expid
                             'NO_COADD'                     // coadd
                             2                              // framenum
                             10                             // numdce : DCEs
                             'MIPS'                         // csmode
// EXPOSURE_INFO: Exposure_Type = 'd1'
// COMMENT: 70A darks
00:03:48.600 MIPS_DARK_CALS                                 // BLOCK: SSC use for 160, 70a and 70b um, 3s, 4s,10s frametimes
                             '70A'                          // MIRROR_POSITION
                             2                              // FRAME_NUMBER
                             5                              // EXPID
// EXPOSURE_INFO: Exposure_Type = 'd2a'
// COMMENT: 70B darks
00:10:19.000 MIPS_DARK_CALS                                 // BLOCK: SSC use for 160, 70a and 70b um, 3s, 4s,10s frametimes
                             '70B'                          // MIRROR_POSITION
                             2                              // FRAME_NUMBER
                             7                              // EXPID
// EXPOSURE_INFO: Exposure_Type = 'd2b'
// COMMENT: 160um Dark s
00:16:49.400 MIPS_DARK_CALS                                 // BLOCK: SSC use for 160, 70a and 70b um, 3s, 4s,10s frametimes
                             '160'                          // MIRROR_POSITION
                             2                              // FRAME_NUMBER
                             9                              // EXPID
// EXPOSURE_INFO: Exposure_Type = 'd3'
00:23:19.800 MIPS_BACKTO_MOBS                               // BLOCK: SSC change MIPS state back to MIPS observe
                             0x003c99a0                     // OPERCESTATE
00:23:30.000 PCS_ATT_DET                                    //
                             'PCS_OBS_B'                    // observer
00:23:31.000 PCS_LOWRATE_MODE                               //
                             'DISABLE'                      // rate_select
00:23:32.000 PCS_PRI                                        //
                             'DISABLE'                      // disable_enable
00:23:33.000 VML_EVAL                                       // Place holder for VML EVAL construct
                             GV_ACTIVE_AORID_FLAGS          // global variable name
                             0x0000                         // value or expression
00:23:33.100 VML_EVAL                                       // Place holder for VML EVAL construct
                             GV_ACTIVE_AORID_KEY            // global variable name
                             0x00000000                     // value or expression
00:23:33.200 VML_EVAL                                       // Place holder for VML EVAL construct
                             GV_AOR_END_TIME                // global variable name
                             NOW                            // value or expression
00:23:33.300 END                                            // Meta command indicates end of expansion



Data Reformatting Requirements

Array Data Desired:

All 3 arrays.

Data Reformatting Option:

Special Instructions:
All DCEs in one cycle of each dark IER must be packed into one fits file with extensions, for a total of four files corresponding to the 3 arrays (2 files for 70).

Task Dependencies


Calibration Dependencies


Output and Deliverable Products

The final product will be a single dark calibration image for each array.

Data Analysis

The data will be processed with the DAT using the appropriate switches for each array (implemented by shell scripts). Mips_enhancer will be used to combine multiple DCEs into one dark current calibration image for each array. Counts will be measured using IDL scripts. Trends over multiple campaigns will be analyzed and compared to the expected spacecraft cooling curve. Note that 24 µm should saturate until the telescope reaches ~45-50 K (by about campaign C-D1) (**but will difference images be saturated???**), 70 µm saturates until ~17 K (about campaign F), and 160 µm saturates until ~9 K (about campaign G-H).
Predicted telescope cooldown curve
Predicted 24um backgrounds (Note: expected point source saturation level has changed to 5.6 Jy)
Predicted 70um backgrounds (Note: expected point source saturation level has changed to 5.3 Jy)
Predicted 160um backgrounds (Note: expected point source saturation level has changed to 8 Jy)

Software Requirements


Actions Following Analysis

Tracking of dark counts in each campaign needs to be cataloged in the appropriate place (web site?).

Failure Modes and Responses

If the data are unusable (missing data, excessive noise, saturation) in a particular campaign, it is probably not worth trying to redo the observation unless multiple campaigns have failed and inadequate time sampling becomes a problem.

Additional Notes