SITR: FORCAST February 19, 2010 Cornell University Herter

19-Feb-102 FORCAST Status FORCAST is up and running in lab at DOAF! Kudos to the FORCAST team o George Gull, Chuck Henderson, Justin Schoenwald o Joe Adams, Luke Keller Schedule o 2/05FriShipped via FedEx Custom Critical o 2/07SunArrived at DOAF parking lot o 2/08MonUnpack & prep for cool down o 2/10WedFORCAST to LN2 o 2/11ThuFORCAST to LHe o 2/12FriFull cold soaked, working nominally o 4/07WedStart of mini line-ops o 4/23FriTA Characterization/First Light Flight

Most Procedures in Place Signed off o Vacuum and Leak Check o Warm Test o Cold Test o CWR Installation o PI Rack Installation o On-Aircraft Cryogen Fill o CWR Removal Not yet signed o Safe to Mate o In-flight access Operational o Mini line-ops plan o First light plan o Line ops plan 19-Feb-103 Airworthiness document signed off as well.

Photos: Loading for Shipment 19-Feb-104

Photos: In DAOF lab 19-Feb-105 Calibration box Electronics Pump out Cooling down

Lessoned Learned In general, everything has gone rather well Chris has done a great job in outfitting the lab o Tools, pumps, etc o But check your H/W and tools: do you have specialty items? o No H/W stock room (nuts, bolts, etc) No real problems with Safety and QA o Mainly in observational mode, updating procedures o Remember safety shoes o You can’t roll crane under load o Make sure you load certify your cart! Operational issue o Access to instrument/lab requires planning o Must have 2 team members + 1 USRA person present 19-Feb-106

Optimizing FORCAST Tweaks to optimize signal-to-noise ratio  Bias: Can increase  G (good) and  G (bad) o Chop frequency:Influences1/f noise contributions o Frame rate:Affects read noise contribution o Mux gain: Affects read noise contribution (high/low capacitance – low cap best) Optimization depends upon background photon flux   G is both bias and background dependent 19-Feb-107 S src = source photon rate S bck = background (ph/sec/pix) t 1 = 1/ (frame rate) n pix = source area (in pixels) RN = read noise S/N = signal-to-noise (one read)

Fore Optics Simulate on-sky (faint) source o Chop and “Nod”  Set and regulate source  T (e.g.  T = 2 K) Checks system with “real” source o Warm & cold throughput 19-Feb-108

9 Optimizing Bias Upper left: S/N vs. bias for LWC low capacitance (low background) mode o 30 micron + neutral density filter Upper right: S/N vs. bias for LWC in high capacitance (high background) mode o 38 micron filter Lower left: S/N vs. well depth for LWC hi-cap mode sigLevel in DN 6800 < sigLevel < 10700

19-Feb-1010 Cornell Non-DAOF activities Prep for new LWC detector (GFY10-11) o New fan-out board o New detector cabling o Modify test dewar for array checkout o FPGA and S/W mods for running array Documentation updates/generation (GFY10-11) o Based on DAOF and flight results Installation and testing of LWC array (GFY11) o Different multiplexor (and size) from current array Response to issues arising from first light flights (GFY10-11) o Update FORCAST operations S/W o Update data acquisition procedures o Update data reduction pipeline o Miscellaneous hardware updates due to unforeseen issues?

Final Comments We’re ready to go Plan to keep FORCAST cold for next two weeks o Further parameter optimization o Occasional “funnies” we want to track down o Testing of IMC o Fine tuning (setting of parameters, quick look FORCAST communications, etc.) Back at Cornell o Will look into digital bias control 19-Feb-1011