HAWCPol / SuperHAWC Software & Operations

1. HAWCPol / SuperHAWCSoftware& Operations J. Dotson July 28, 2007

2. Instrument Remote Control (IRC) Overview • IRC was developed by GSFC. (Troy Ames and co.) • HAWC Data Acquisition Software is a specialization of the Instrument Remote Control (IRC) software. • Provides a mature product to base HAWC software • Cost savings due to code reuse. • Has been used on SPIREX, GIZMO, SHARC2 (among others) • IRC provides a platform independent, extensible program • Written in JAVA (platform independent!) • Much of the instrument specific information is stored in XML configuration files. (No re-compiling necessary for changing parameters.)

3. Goddard’s Instrument Remote Control Software • JAVA and XML • Data stored in FITS format. • Currently in use with SHARC II

4. HAWC Architecture On TA housekeeping Data Broadcast Client (IRC?): Science Station 0% complete Cryostat Computer 50% complete Client: Engineering station adr Flow meter Master Process (IRC) 65% complete Client: Science station OMS Data Broadcast calibrator Client: Education station Data Server Process (IRC) 95% complete Rack computer telescope Anywhere on sofia In PI Rack Data electronics Data Broadcast

5. HAWCPol & SuperHAWC Architecture On TA housekeeping Data Broadcast Client process: Science station adr Red items: Need significant changes for SuperHAWC Cryostat computer Flow meter Fuschia items: Need significant changes for both HAWCPol & SuperHAWC Master Process OMS Data Broadcast Clients will require changes for either HAWCPol or SuperHAWC, but since they are in a early phase of development, no code rewrites are necessary, just requirement changes. calibrator or Polarization Modulator Data Server Process (IRC) Rack computer telescope In PI Rack Data electronics Data Broadcast

6. Hawc Observing Modes • HAWC is planning two primary observing modes: • Chop/Nod Mapping • Continuous Scan Mapping • Only Chop/Nod Mapping is planned for initial delivery Hawc Data Pipeline Status • Chop/Nod Mapping Pipeline is defined -- but only the first step is implemented. (Demodulation of chop rate data is performed by the Data Server Process.)

7. HAWC Data-Taking Hierarchy and Terms: Chop/Nod Mapping • HAWC detectors: “sample rate data” • HAWC outputs images at ADC sample rate (1-4 kHz) • Chopping secondary: “chop rate data” and “display rate data” • telescope secondary (ALWAYS) chops between source and reference positions at about 10 Hz; demodulation at chop frequency produces chop rate data • multiple chops co-added for real-time display to produce display rate data • Telescope nodding: “nod pair data” • telescope nods to switch source & reference sky beams at < 1 Hz • multiple nods for each position in a dither series • total integration time of a few tens of sec per nod position • Telescope dithering: “dither series” • telescope moves through a pre-defined sequence of nod positions • offsets are small, non-integral numbers of pixels, to smooth over detector nonuniformities • Telescope mapping: “map” • telescope executes a sequence of dithered stare & nod observations • dither series obtained for a grid of map points • large separations between map points (of order 80% of detector dimensions)

8. Planned HAWC Data Processing Pipeline:Chop/Nod Mapping • Demodulate sample-rate (ADC rate) data to produce chop-rate images • input tables provide chopper waveform for demodulation and relative detector phases • output both “in-phase” and “out-of-phase” demodulated images (“p0”, “p1”) • Demodulation is performed during flight. Delivered data files contain demodulated data. (Raw data can be stored, but not currently baselined.) • Co-add chop-rate images for each telescope pointing in a “stare & nod” sequence • Integrate chop-rate data over multiple chop cycles to generate display rate data • Integrate over full nod dwell time to generate nod rate image data • Process coadded chop-rate images to remove detector artifacts & nonuniformities • e.g.: apply gain map, bad pixel mask • Form nod pair difference image for each position of a dithered series of telescope pointings • Combine dithered image series into a mosaic & establish image coordinate system • Combine dithered mosaics obtained over map grid into a map image • Calibrate map image pixel intensities

9. HAWC Data Pipeline: Stare & Nod Mode Chop period, phase, waveform Display rate, Nod info Flat field, bad pix mask Demodulate & deglitch Integrator (coadder) Flat field & remove bad pixels Level 0 HAWC Level 1 Sample rate data stream Telescope pointing history Mosaic images Calibrate image Level 2 Level 3 Flux calibration parameters Final image

10. FSI: Operated by SSMOC Instrument stays at SSMOC All upgrades/changes must be approved. Open to proposals from everyone Data is archived by SSMOC Requires: Fully defined & tested observing modes (AOTs) Data files must be SOFIA compliant Data Pipelines must be delivered to SSMOC A *lot* more documentation! PI Instrument: Operated by Instrument Team Lives at home institution Upgrades require only airworthiness reviews Proposers must collaborate with Instrument Team Data *not* archived in SSMOC SOFIA Facility Science InstrumentorPI Instrument?

11. What is HAWCPol / SuperHAWC? • HAWC is planned to be an FSI. (Phasing of first light & delivery as FSI depends on funding) • The significant investment required to upgrade to SuperHAWC would probably require FSI status. • Might be possible to define HAWCPol as a “non-FSI” observing mode of HAWC -- but, if it works well, I would expect pressure to convert to a FSI mode.