1. Pan-STARRS Seminar: IPPEugene Magnier Pan-STARRS Image Processing Pipeline An Overview IFA Pan-STARRS Seminar 735 October 6, 2004

2. Pan-STARRS Seminar: IPPEugene Magnier ● Image Analysis Steps / Science Data Products ● IPP System Architecture & Motivations ● Software Organization (PSLib / Modules / Analysis Stages) ● PS-1 vs PS-4 implications for IPP Summary of Topics

3. Pan-STARRS Seminar: IPPEugene Magnier OTIS PSPS MOPS Science Client IPP World Users Solar System Community static sky images other data metadata, detections raw images metad ata, detec tions metadata metad ata, detec tions IDs orbits identifications filtered detections & metadata Cameras Telescopes static sky images PS Subsyst em Legend pixel data meta & object data Exte rnal Syste m commands photons IPP within Pan-STARRS

4. Pan-STARRS Seminar: IPPEugene Magnier IPP Image Processing Responsibilities: ● Processing of single images (phase 2) ● remove instrumental signature ● bright object detection / basic characterization ● initial astrometric & photometric calibration ● Merging of image groups (phase 4) ● warp & resample to reference image grid ● stack and CR-reject ● subtract static sky image ● measure objects on difference & summed images ● update static sky ● Construct Calibrations ● basic calibration images (bias, dark, flat, etc) ● derived calibration images (fringe, flat-field corrections, etc) ● other calibration data (optical distortion parameters, zero-points, etc ● Analysis Trace & Monitor ● System Characterization

5. Pan-STARRS Seminar: IPPEugene Magnier Phase 2 Issues ● Flat-fields are corrected based on stellar photometry

6. Pan-STARRS Seminar: IPPEugene Magnier ● Flat-fields are corrected based on stellar photometry ● fringe frames may be built with a monochromatic dome source ● fringe correction may be based on atm. emission line observation Phase 2 Issues

7. Pan-STARRS Seminar: IPPEugene Magnier Phase 2 Issues ● Flat-fields are corrected based on stellar photometry ● fringe frames may be built with a monochromatic dome source ● fringe correction may be based on atm. emission line observation ● minimal object parameters (x,y, mag, stellar/non-stellar, basic shape) ● high detection threshold (~20 sigma?) ● we keep postage-stamp images on a (small) subset of objects

8. Pan-STARRS Seminar: IPPEugene Magnier Phase 4 Issues Phase 2 images: 0.3 arcsec/pix Chip/Cell units Phase 4 images: 0.2 arcsec/pix Static Sky cells ● overlapping pixels are mapped to common (sky) reference frame ● Object detections are perfomed on: ● Difference Images (P4D) to low threshold (~3 sigma) ● Improved Summed Images (P4S) to modest threshold (~5-10 sigma) ● Static Sky is updated ● note caveat in CR rejection for sequential vs simultaneous images cleaned - = - = static skydifference image (P4D) also yields transient-free summed image (P4S) and updated static sky image.

9. Pan-STARRS Seminar: IPPEugene Magnier Static Sky Analysis ● Detailed object analysis including ● complex object deblending a la SDSS ● simultaneous multi-band analysis ● Analysis is NOT performed nightly ● Static Sky changes slowly ● Goal is deep science, not variability ● Analysis is computationally more intense than P2,P4 ● Rolling Analysis: ● ~1 degree RA strips per day ● only RA within 10 degrees of solar RA

10. Pan-STARRS Seminar: IPPEugene Magnier IPP Data Products ● Imaging Data Products: ● Static Sky images ● Postage Stamp Images ● Object Measurements ● P2, P4S, P4D, Static Sky ● rudimentary object associations ● photometric / astrometric calibrations ● Metadata ● image information from summit ● weather & other ancillary summit data ● analysis statistics ● analysis history ● calibration information All external data products are sent to PSPS for external access. MOPS & other science clients also receive data products directly.

11. Pan-STARRS Seminar: IPPEugene Magnier Additional Image Analysis Issues Analysis is staged by data unit: ● Phase 1: analysis preparation (mosaic) ● Phase 2: single image analysis (chip) ● Phase 3: calibration improvements (mosaic) ● Phase 4: image combinations (frame) Data has units of: cell, chip, mosaic, image group (major frame) Precision goals (PS-4): ● 30 milliarcsec relative astrometry ● 100 milliarcsec absolute astrometry ● 5 millimag relative photometry ● 10 millimag absolute photometry (internal system) These goals can only be efficiently met after we have produced a Pan-STARRS Astrometric and Photometric reference catalog

12. Pan-STARRS Seminar: IPPEugene Magnier Hardware Organization: optimized for our parallel processing

13. Pan-STARRS Seminar: IPPEugene Magnier IPP System Architecture state machine (not event driven) system infrastructure is independent of analysis architectural components are stand-alone entities

14. Pan-STARRS Seminar: IPPEugene Magnier External Libraries (glibc, glib, gsl, CFITSIO, FFTW, SLALIB, etc) PSLib [includes wrappers to externals] (images, vectors, errors, syscalls, etc) modules (debias, convolve, flatten, findobjects, etc) processing scripts / analysis stages (phase 0-4, cal 1- 3, AstromRef, PhotomRef) parallel processing controller processing scheduler External Systems (Lustre?, GFS?, Mysql, Apache, etc) Software Tools: CVS SWIG bugzilla doxygen eups autoconf make gcc IPP Software Architecture

15. Pan-STARRS Seminar: IPPEugene Magnier Pan-STARRS 1 (especially for AP Survey) ● no simultaneous images ● little or no Phase 4 analysis (first year) ● no static sky ● limited reference data ● keep all raw data (~1 year) ● multiple analysis passes primary PS-1 goals” ● AP Survey ● verification surveys (MVP & IVP)

16. Pan-STARRS Seminar: IPPEugene Magnier An Advertisement... We would like to hire 2 - 3 grad students for short-term IPP demo projects: ● M31 variability analysis ● SDSS / Megacam proper motion study ● CFH12K / 2MASS i-band dropouts ● SkyProbe A&E development and test