Night three (of four) of the last ARCoIRIS Commissioning/Engineering: tests are on-going.

• Just after sunset, Omar E. performed a series of f/8 pointing tests.
• Marco B. has been working extensively, while on vacation I might add, on the instrument control sotware problems that arose last night. He paid special attention to fixing the FITS header problems (length, variation in destination), especially in regard to the final read mode and Fowler/co-add images. Tests showed that For normal science images (Fowler=1, co-adds=1 and write expo enabled) all FITS headers are normal. For Fowler16, co-add=1, Fowler=1, co-add-5, and Fowler=16 and co-adds (all write expo=Y) all have normal FITS headers, so I think MB's software upgrades have worked. 
• Marco B. also worked on the nod to background box (BB) procedures, with respect to the accuracy of offsetting to the BB regions, and for multiple slit nods. We were not able to test this feature tonight, and have deferred its testing until tomorrow night.
• Katelyn Allers has been working of ammending her code to take into account the disrupted FITS headers for spectra acquired last night. She notes something interesting: While there were many images that had different FITS headers/lengths, there were only four images that had shortened or absent headers in either image (either the accum image, or the science image). For the ABBA sequences ... 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 It was frames 188, 192, 196, 200 that had odd FITS headers ... i.e, always the second B-nod. This might be of interest to Marco.
• To assist in field identification of faint sources, we would like the mini-compass on the SV image Detector window to rotate with rotator angle. At the moment, 270-degrees is actually N-S, and yet the needle points to the 3-oclock position @270-degrees. We should have the needle point North (which is the 9-o'clock position in reality).
• For the SV-detector, we really be able to apply a bad-pixel mask, which MB would have created during detector testing. For faint sources, field identification is currently very difficult.  In fact, we should have a feature where we can save an SV-image, and have a button to press where we can subtract that image from the current SV-readout. This would improve the contrast immensely on the updating SV image.
• Currently, while there is a focus script which works well, it is there is no tool to interpret the results -- one has to open each image individually, work out the FWHM, check the header for the focus value, and enter those values into a text file, and then plot up that relation ... this has already been largely automated/scripted for Mosaic and NEWFIRM, so we should be able to do this easily for ARCoIRIS. This is an important upgrade, should we should raise its priority level.
• If one sets the Parallactic Angle to the Rotator angle, there is a 90-degree offset in reality. For instance, we can show that the rotator is N-S when the angle reads 270-degrees, however, when a star is on the meridian, the parallactic angle is 0-degrees (or 180-degrees), and the slit must be aligned N-S (eg., see Figure 3, http://www.gb.nrao.edu/~rcreager/GBTMetrology/140ft/l0058/gbtmemo52/memo...).  Therefore, there is a discrepancy between the N-S definition by the rotator (90-270 degrees) and the N-S definition by the P.A. definition (0-180 degrees). We therefore think that there is a 90-degree offset between the rotator and the true P.A., but we'd welcome a second opinion.
• The are three Exposure Time keywords in the FITS headers, 'MEXPTIME', 'EXPTIME', and 'REXPTIME', but there are no comments as to the differences between them. MB, at your earliest convenience, please add a comments field in the FITS header entries.
• On the Spectrograph Detector window, it would be good to have a "test" button, so that a test exposure can be taken (such as test.fits) that one can obtain a quick-look spectrum. This test.fits file can be over-writable.
• For the "write expo" option, Marco, can you please write out the same file number but instead of calling the image SPEC_namennnnexpo.fits, call it EXPO_namennnn.fits ? That would help with data housekeeping enormously.
• Neither OBSERVER3 or OBSERVER2 has working audio/mic equipment for SkyPe/google-chat telecons. CISS, please installed appropriate equipment. 
• The observer2 keyboard is VERY sticky, with the shift button having to be absolutely forced to be engaged. The single- and double-quotes key produces strange symbols that webpages, xterm command lines and IDL command lines cannot parse. This keyboard needs changing *urgently*.
• ​In terms of the OBSTYPE=calibration, MB has been working to improve the TCS-handshake, and remote operating control of the lamps. He also tested the stability of the comparison lamp observation macro. We were not in a position to test these changes and updates this evening. We're planning on doing these tonight, on our last night of Commissioning/Engineering.
• Katelyn Allers installed her updated ARCoIRIS data reduction modules into the Spextools package on OBSERVER2. She also spent nearly three-hours training DJJ on how to use the data reduction package from beginning (raw data in) to end (publishable quality science data out) -- thank you KNA.
• Right at the end of the night (@06:30), the ARCoIRIS control software crashed, and despite repeat re-starts, was unrecoverable. Marco, please check that both detectors are powered off.

• Please could we have more decaffinated coffee in the Blanco 4m kitchinette ?