MIPS Data Processing for SINGS

George J. Bendo & Chad Engelbracht

(A ''George's Adventures in Learning OpenOffice'' Presentation)

Overview

● Brief review of MIPS● Description of observational data● Data checks● Mosaicing data● Parallel pipeline processing

MIPS Overview

Three detector arrays

– 128x128 24 m array

– 32x32 70 m array

– 2x20 160 m array

Will provide

– Photometric maps

– Low-resolution spectra in55 - 95 m range

MIPS Observing Modes for SINGS

Scan Mapping (or Photometry Mode for smaller targets)

– Telescope drifts by targets as mirror in MIPS keeps image steady for multiple adjacent BCDs

– Each AOR may contain tens to thousands of individual BCDs

– Each observation consists of 2 AORs (for spatial sampling and asteroid rejection)

SED Mode

– Telescope slit is pointed at a series of adjacent locations to form data cube

Example Data: NGC 3184

Generated simulated data for demonstration

– Started with U-band image from NED

– Convolved image with MIPS PSFs

– Flux calibrated data with IRAS data

– Added images to backgrounds provided by H. Dole et al.

Scanned region of NGC 3184 (70 m)

Example of MIPS Scan Map Data

Data Checks

Fits header checks– Basic header keywords

– Proposal & observer name

– Target name

– AOT & AOR information

– Observing mode

– Integration time

– Coordinates

– Map or SED observing parameters

Pipeline data checks

– Number of BCDs

– BCD image size

– Movement of target from BCD to BCD

– Noise levels per BCD

List of Fits Header Keywords in Check

General Keywords

● KEYWORD

● NAXIS

● NAXIS1

● NAXIS2

● TELESCOP

● INSTRUME

● CHNLNUM

● AOT_TYPE

● AORLABEL

● FILETYPE

● FOVID

● FOVNAME

● ISPRIME

● RDOUTMOD

Scan Map Keywords

●SCANRATE

●REQ160

●FASTRES

●NMAPCYCL

●NSCANLEG

●SCANLEN

●STEPFOR

●STEPREV

● OBSRVR

● PROGID

● SAMPTIME

● OBJECT

● RA_HMS

● DEC_DMS

● RA_CMD

● DEC_CMD

Photometry Super-Resolution Keywords

●LARGE24

●NCYCL24

●LARGE70

●NCYCL70

●LARGE160

●NCYCL160

SED Keywords

●CHOPDIST

●NCYCLES

●COLSTEP

●ROWSTEP

Mosaicing

The individual frames will be combined with the mips_enhancer software, which will produce a mosaic of the images as well as enhancing the data.

Further checks of the observations will include checking the signal-to-noise ratio of the final data product, checking the quality of the PSF, and comparing the fluxes to IRAS fluxes.

The final data products will include the straight mips_enhancer output and trimmed, background-subtracted, resampled versions.

Comparison of Input and Output 24 m Data

Comparison of Input and Output 70 m Data

Comparison of Input and Output 160 m Data

Parallel Pipeline Processing

To check the data products from the SSC pipeline, the raw MIPS data will also be processed with developmental software written by the MIPS group

● mips_sloper

– Processes charge ramps into slopes for all pixels

– Removes cosmic rays

– Performs transient correction● mips_caler

– Data calibrated

– Dark current subtracted

Example of Output from mips_sloper

Summary

● Prepared series of checks on data output to check observations

● Have software for producing simulated data

● Have software for mosaicing pipeline data from SSC

● Have developmental software for additional parallel pipeline processing

Mosaicer Schedule5 Sep 2002 (Version 1)

– No interpolation (directly from BCD to final mosaicked image)

– Distortion correction and outlier rejection

Late 2003 (Version 1.n)

– MIPS/SINGS review of progress and possible decision to use an intermediate version for SINGS MIPS deliveries

– May decide to continue to use version 1

2003-2004

– Add instrumental signatures removal based on redundancy

– Iterative approach driven by actual MIPS data

– Stim flash latents, long-term drift, ...

Late 2004 (Version 2)

– Will be used to create the final MIPS SINGS data products

Simulator ScheduleJun 2002

– Given AOR and image, will produce input for mips_enchancer

Aug 2002

– Produce input for full MIPS pipeline (charge ramps) including distortions

Sep 2002

– Add the capability to do SED AORs

Dec 2002

– Add instrumental signatures

● Cosmic rays● Stim flash latents● Long term drift