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

5. Master Process Cryostat computer Data Server Process (IRC) housekeeping adr Flow meter calibrator telescope Data electronics OMS HAWCPol & SuperHAWC Architecture In PI Rack On TA Client process: Science station Rack computer Data Broadcast Polarization Modulator or Red items: Need significant changes for SuperHAWC Fuschia items: Need significant changes for both HAWCPol & SuperHAWC 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.

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

10. SOFIA Facility Science Instrument or PI Instrument? 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

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.