Dec 8, Line Widths/ Resolution (1) ThAr UNe Sky Solid: fiber 150 Open: fibers 10/290 Each point is median of results from lots of frames (few per night for lamps, one per night for skies) Simple Gaussian fits Some lines appear to be resolved Wavelength range/dispersion as expected Resolution close to or achieves SRD specification of R~22500 (significant improvement from pre-shutdown in red)

Dec 8, Line Widths/ Resolution (2) Stability and monitoring: line widths appear to be constant in time (mostly?) Significant variation across chip not unexpected

Dec 8, Line Widths/ Resolution (3) Issues Moderate undersampling in blue Resolution varies across chip (not always best in center!) Beware sky lines for LSF characterization? Caveat: Measurements from uniformly illuminated fibers Possible LSF measurements from fits to telluric lines, or perhaps asteroid

Dec 8, S/N and throughput SRD calls for S/N=100 at H=12.2 in 3 hr exposure per pixel at 1.6 microns, airmass=2, seeing=1.5”, clear conditions. Pixel is taken to mean a “Nyquist sampled pixel”; since dithering provides spectra at ~2X Nyquist sampling, this means S/N=70.7 per dithered pixel. S/N calculated for all 500s exposures taken to date, using median S/N for 12<H<12.2, where noise comes from noise model Some S/N verification from looking at “featureless” region of tellurics and comparing rms after smoothed spectrum removed with calculated S/N; factors generally between 0.5 and 1.0 Dotted lines are SRD requirement assuming signal-limited exposures Note that S/N in excess of SRD doesn’t necessarily imply we are overexposing because we could reduce number of exposures

Dec 8, Persistence APOGEE detectors have noticeable persistence issues Blue detector has “superpersistence” over top ~1/3 rd Some characterization done in spring, but little or no effort since then Attempting to minimize as much as possible: Cold shutter installed and in routine use Dome flats are only nighttime frames taken that aren’t science frames; taken AFTER science exposures of a plate, followed by two short dark Evening cals minimized, and taken early, with more complete calibration set taken in morning; kept cal exposures to a “minimum”

Dec 8, Dither pair accuracy Modifications made to mechanism algorithm between runs 2 and 3 made significant improvements! SRD spec: 0.5 micron accuracy or pixels (dotted lines) Algorithm for combining dither frames should handle arbitrary shift size so long as it is well measured, although deviations from 0.5 lead to correlated noise issues Detailed tests on understanding whether 2 samples are sufficient for full LSF reconstruction have not yet been done (dither combination of monochromatic sources complicated by intensity variations): test on single line looks good

Dec 8, Observing software Observing software functional and relatively stable: ICS software STABLE : some modifications have been made for dithering and for safety interlock. Possible desire to implement additional exposure type keywords Instrument control MOSTLY through SOP: few items still done with STUI scripts: cartridge change, evening cals, morning cals. Appears to be going smoothly, but possible desire to incorporate everything into SOP (priority? manpower?) Python quicklook actor MOSTLY STABLE: handles header annotation of frames, checksum vs raw frames, initiates quicklook, quickred, bundling. Some issues with long term stability, so restarted every day automatically (TBD priority for modification? Manpower?) Quicklook/webapp for observing support to be discussed later Morning cron job checks for missing bundled frames, creates MD5 sums for SAS transfer SAS transfer of raw data running stably during subsequent day

Dec 8, Observing support Observers have been given primary contacts: Frinchaboy: scheduling issues Holtzman : actor / observing issues Shetrone: observing issues Alerts set up for instrument parameters, disk space Things seem to be running fairly smoothly (from team perspective, but it’s really the observer perspective that is important here!)

Dec 8, Calibration data Calibration data is taken on a regular basis: Daily internal cals: ThArNe and UNe lamps at 2 dither positions Quartz exposure 3 long darks Internal flats Monthly internal cals, plan not yet routine – needs improved procedure/responsible party 10 long darks 10 internal flats Persistence monitor Sparse pack quartz On-telescope calibration data: Mirror petal flats taken after every cartridge to 1) provide PSFs, 2) provide fiber to fiber throughput Sky frames taken once per night (4 150s exposures) for LSF monitoring (but note possible issues with these) Every plate has sky and telluric star fibers for sky subtraction and telluric correction Overall approach has been relatively conservative, however, little or no impact on efficiency from internal cals, some from on-telescope cals

Dec 8, Calibration data (2) Calibration data suggests instruments appears to be relatively stable: Wavelength cals (plots?) Flat fields (images?) Darks (images? Plots?) LSFs (previous plots?) Appears that current internal calibration data is sufficient (and taking more that might possible be relevant would probably imply taking an efficiency and persistence hit) Reduction pipeline currently not doing great job at sky subtraction and telluric correction Relatively little effort dedicated to date Not yet clear if calibration data is sufficient Have been using 35/35 sky/telluric as opposed to original plan of 25/25

Dec 8, Data inspection / QA Data is now being routinely processed (although almost certainly not optimally!) quick manual construction of pre-processing file (check on plate/exposure assocation, cal frames, etc.) done morning after observing (~15 minutes) based on observing logs Raw data cubes downloaded from SAS, generally by night following observing Reduction started second day after observing, processed through 3D->2D, 2D->1D, sky correction, dither combination, RV measurement in 6-8 hours per plate, all plates reduced simultaneously on multiple processors Calibration monitor data processed in parallel (not yet quite routinely implemented)

Dec 8, Data inspection / QA (2) Data reduction pipeline produces web pages for quick inspection / QA Summary MJD QA page: Highlights any frames for which no reduced frame exists Frames with bad checksums Missing sequence numbers plot of zeropoints for all exposures, continuum sky levels for all exposures Table of all science exposures, with derived S/N, zeropoints, attempts at identifying missing and faint fibers Summary web page for each plate: Zeropoint, continuum sky, and S/N plots vs mag for every exposure Maps of zeropoints, sky as f (zeta, eta) Web page of all dither-combined spectra and error spectrum for each plate Links to RV page showing best matching spectrum Some of these are getting looked at now Need to develop specific checklist of what should be looked at (may motivate some reorganization of information on pages), but I think we are very close This checks mostly issues with conditions, data issues, and data reduction issues, thus indirectly instrument health

Dec 8, Data inspection / QA (3) Instrument health montoring through daily calibration monitor output: not yet fully implemented, but many pieces in place (few days work) Wavelength calibration: start/end wavelengths, wavelength solution vs. fiducial solution LSF: line width monitoring Dither pair separation (should be included in plate pages) Daily flat vs fiducial flat Daily dark vs fiducial dark Cartridge flats vs fiducial (perhaps should be included in plate pages) Need to develop specific checklist of things to look at and simple web interface (high priority, getting close to implementation) Increment of survey reduced data statistics RV histogram for plate Sky map of observed plates S/N histogram Delta mag histogram