<? echo "MIPS-".$caid." IOC Task Cookbook"; ?>

Principal: Almudena Alonso
Deputy: Susan Stolovy
Data Monkey(s): Almudena Alonso, Casey Papovich, Susan Stolovy
Priority:
Downlink Priority: Normal
Analysis Time: 24-48 hours
Last Updated:

Objective

To obtain a 24micron Routine Photometry Flatfield in the large field option.

Description

We will obtain IOC acceptable routine 24um PHOTOMETRY mode large field flatfields (this task is repeated a number of times in different IOC campaigns) to be used on a regular basis.

Since this task is repeated a number of times during IOC, we will observe different regions of the sky each time. The task will check for possible variations of quality of flatfield or saturation. This task will also be useful for screening regions of the sky to obtain flatfields in SIRTF routine operations.

This task is executed in:

MIPS Campaign V
MIPS Campaign M001

Data Collected

A 4 point dither map (1 cycle) will be obtained at 24microns with 3 second DCEs in a region of the sky chosen to avoid bright point sources. The map will require about 16.7 minutes of observing time. This is the AOR file overlaid on the sky:

HEADER: FILE_VERSION=7.0, STATUS = PROPOSAL

      AOT_TYPE:  MIPS Photometry
     AOR_LABEL:  MIPSP-943-Nov27-Jan07
    AOR_STATUS:  new

 MOVING_TARGET:  NO
   TARGET_TYPE:  FIXED CLUSTER - OFFSETS
   TARGET_NAME:  zodi_0a
  COORD_SYSTEM:  Equatorial  J2000
     POSITION1:  RA_LON=0h19m54.66s,  DEC_LAT=-4d33m52.3s
     OFFSET_P2:  EAST_ROW_PERP=400.0",  NORTH_COL_PARA=0.0"
     OFFSET_P3:  EAST_ROW_PERP=800.0",  NORTH_COL_PARA=0.0"
     OFFSET_P4:  EAST_ROW_PERP=1200.0", NORTH_COL_PARA=0.0"
OFFSETS_IN_ARRAY:  NO
OBSERVE_OFFSETS_ONLY:  NO
OBJECT_AVOIDANCE:  EARTH = YES, OTHERS = YES

    MICRON_24: FIELD_SIZE = LARGE, EXPOSURE_TIME = 3, SKY_OFFSET = 350.0, N_CYCL
ES = 1
SPECIAL: IMPACT = none, LATE_EPHEMERIS = NO,SECOND_LOOK = NO
RESOURCE_EST: TOTAL_DURATION=1008.9585, SLEW_TIME=115.4, SETTLE_TIME=144.3585, S
LEW_OVERHEAD=180.0, SPECIAL_OVERHEAD=0.0, UPLINK_VOLUME=2007, DOWNLINK_VOLUME=81
20880, VERSION=S8.9.0
INTEGRATION_TIME: MIPS_24=35.651585,MIPS_70=0.0,MIPS_160=0.0

Data Reformatting Requirements

Array Data Desired:

All Arrays

Data Reformatting Option:

NORMAL

1 FITS file per AOR per array.

Special Instructions:

Task Dependencies

MIPS-100: 24 um first light
etc.

Calibration Dependencies

Dark

Output and Deliverable Products

24 micron mosaic of the observed region. This may be useful for IRS to select their flatfield regions.

24micron flatfield obtained in PHOTOMETRY large field mode.

A star observed at a grid of positions across the array will be flatfield to check the quality of the flatfield. We will provide an array map showing the location dependences -if any- of the photometric sensitivity.

Data Analysis

Standard Pipeline reduction using the DAT and/or SSC Pipeline. If using the DAT, we will run MIPS_SLOPER to do the dark subtraction, among other things.
Produce a mosaic of the observed region using MIPS_ENHANCER to check for bright sources.
Median combine 56 images (with some rejection algorithm, e.g., 3sigma rejection) using the IRAF "imcombine" task to create a flatfield. Alternatively, once the flatfield DCEs are screened for possible saturation, etc, we can use the MIPS_ENHANCER to create the flatfield frame using an appropriate rejection algorithm.
Flatfield star observations at different positions across the array. We can use observations of the Focal Plane Survey: MIPS-130 and MIPS-131.
Aperture photometry on star using the IRAF "phot" task to measure flux. We will use the tasks: photpars, fitskypars to set up the photometry parameters (aperture, sky/background estimate).
Comparison of star aperture photometry at different positions across the array to determine flatfield accuracy.
Once the task is executed more than once:

we can look for possible flatfield variations with time/region of sky used
we can determine the number of DCEs necessary to construct a 'super' flatfield (see A. Alonso's report on flatfield/IC simlations; NEED TO ADD LINK TO FLATFIELD MODEL WEBPAGE). NOTE: According to our flatfield simulations we will need approximately > 60DCEs at 24 microns (depending on the zodi brightness) to get a flatfield with an accuracy of 0.2% (rms, over the whole array).

Software Requirements

DAT
IDL
IRAF

Actions Following Analysis

If S/N and quality of the fialfield requirements are met, it will be put in the calibration data archive for general use.

Failure Modes and Responses

If region of the sky used is saturated, this region will be removed from the list of flatfield regions (Jeonghee Rho's list of flatfield regions). This task is repeated a number of times with different regions of the sky. If regions used are all saturated, we will look for different regions of the sky.