2018 Nov 26 - Dec 14
GNIRS was removed from the telescope to work on filter wheel #2 which had been showing increasing instances of not going into position reliably. The filter wheel datum switches were replaced on both filter mechanisms, a temporary light baffle was removed from wheel #1, and dust was removed from the filters using CO2 snow.
2018 Jun 20-25
Re-seated the detector controller boards, replaced the sequencer board, and replaced a voltage regulator. The read noise levels are now back to normal.
2018 Jun 5
The detector controller is producing higher than normal read noise; investigation is underway.
2017 Aug
The GNIRS cold heads were refurbished, the filter wheel bearings were replaced, the filter wheel baffle was replaced and isolated (it was rubbing and eroding onto some filters), and the filters were cleaned.
6 Nov 2014
Following the August/September 2014 warmup and abbreviated engineering work (the new short red camera lens was not installed, and thus the short red camera remains unavailable until further notice), GNIRS was experienced cooling problems.Following replacement of cold heads it was cooled successfully and was reinstalled on the telescope for scientific use on 14 October. The ice absorption at 3.0-3.2 microns has been reduced to 10% or less, and the instrument is usable in that wavelength range (but currently with only the long red camera). Installation of the Pk50 blocker in the Y filter holder has eliminated the long wavelength leak and the Y filter is now available for imaging science.
25 Apr 2013
The replacement of the cracked lens in the short red camera and installation of a blocking filter for the leak in the Y-MK filter are postponed until July/August 2014. For the rest of 2013A, GNIRS will be off the telescope the last three weeks of July, during which we will replace the cold heads and GNIRS will be warmed while pumped to remove any ice contamination. We expect to have GNIRS back on the telescope and available for science in early August. Technical assessments of 13B GNIRS proposals that use the short red camera are taking into account with the possibility of using the long red camera instead.
08 Feb 2013
GNIRS will be offered in all modes for the 2013B call for proposals. Ahead of that semester we intend to replace the cracked lens in the short red camera (see the August 2012 updates on this page), and also block a leak in the new Y-MK filter.
21 Dec 2012
IRAF configuration files are now available for all supported GNIRS modes. See the Nov 15 status update for more information and instructions for using the files. These files are also part of the recent v1.12 beta release of the package.
array.fits
apertures.fits
config.fits
nsappwave.fits
bad pixel mask
12 Dec 2012
Continued GNIRS checkouts have been hindered by an extended period of poor weather on Mauna Kea. Nonetheless, almost all modes have now been released for science use. The exceptions are imaging with the new Y, J and K Mauna Kea filters and observations with the laser guide star. Weather permitting, GNIRS+LGS will be checked out during the next laser run, scheduled to start on Dec 18.
15 November 2012
As part of the recent GNIRS work, some FITS header keywords were modified to reflect the fact that a new camera lens was installed and the array rotation changed slightly. The released version of the Gemini IRAF package is not compatible with the new headers, so users reducing GNIRS data taken since November 2012 will need to download the following configuration files:
array.fits
apertures.fits
config.fits
nsappwave.fits
Using the files is quite straighforward; they replace the versions supplied with the package and are given as command-line parameters to various reduction tasks. Users following the reduction example on this page would use slightly modified calls to nsprepare, nsflat and nswavelength, as follows:
nsprepare @all.lis shiftx=INDEF shifty=INDEF obstype=FLAT fl_correct- arraytable="path/to/array.fits" configtable="path/to/config.fits"
nsflat rn@QHflats.lis flatfile="QHflat.fits" fl_corner+ process="fit" order=5 lthresh=10. thr_flo=0.35 thr_fup=4.0 aptable="path/to/apertures.fits" fl_inter+
nswavelength arc_comb coordlist="gnirs$data/lowresargon.dat" fl_median+ threshold=300. nlost=10 fwidth=5. nsappwavedb="path/to/nsappwave.fits" aptable="path/to/apertures.fits" fl_inter+
At this point, the modified files are only available for the XD mode that was released for queue observations last week. Further updates for other modes will be provided shortly. These changes will be included in the next Gemini IRAF package release, scheduled around the end of the year with support for the new instruments at Gemini South.
09 November 2012
GNIRS was reinstalled on the telescope on November 07 and nighttime checkouts have started. The sensitivity of the instrument in the popular short camera cross-dispersed (XD) mode is comparable to previous performance and ITC predictions, and the number of radiation events with the new lens is dramatically decreased. The instrument has been released for queue observations in the XD mode and further checks of the remaining modes are planned for the coming week. The web pages will be updated with more information about GNIRS' performance as we analyse the data.
16 October 2012
GNIRS has now been checked out in the lab and will be shipped to Mauna Kea in the morning. Once there, it will undergo its first cooldown since before this round of engineering work. All mechanisms will be tested and recalibrated ahead of the instrument being mounted on the telescope, scheduled for November 07. Although we will then have a fair amount of on-telescope commissioning work to do, we plan to test and release modes in stages, so that GNIRS is available for science use as soon as possible.
20 August 2012
The reassembly of GNIRS is due to start in the next few days, to be followed by an extensive series of tests in the lab. A replacement short red camera lens will be obtained (the vendors we contacted were not optimistic about stoning out the crack), but the procurement will take ~12 weeks. Delaying the reassembly that much would make GNIRS effectively unavailable for the planned 2012B queue observations, so the lens will not be replaced at this time and the short red camera will be unavailable in 2012B and 2013A. The PIs of the three affected 2012B queue programs will be contacted to explore the possibility of using the long red camera for their science instead. (See this page for a comparison of GNIRS' cameras and capabilities.)
02 August 2012
GNIRS is now in pieces in the instrument lab at the Hilo Base Facility. Many mechanisms, switches, cables etc. have been inspected, adjusted and fixed, and the new filters have been installed in the filter wheels. As the camera barrel was being dismantled for the lens replacement a few days ago, the engineers noticed a small crack in the edge of one of the lenses in the short red camera (used for work in the thermal IR). We are currently exploring the options (stoning out the crack, using the lens as is, procuring a new lens, or putting in a dummy lens until GNIRS can be opened again). A decision will be made once we have a good idea of the risks of these options and the schedule implications and effect on science use with the instrument.
08 June 2012
GNIRS has now been dismounted and will soon be transported to Hilo for a period of upgrade and maintenance work. We expect to see GNIRS on the telescope again towards the end of 2012.
25 May 2012
Having been removed from the telescope to allow a laser AO run, and more cold head work, GNIRS is now back on and being used for queue observations again. We will dismount the instrument on June 07 to start preparations for the replacement of the lenses with radioactive coatings, installation of new filters, and other maintenance work. As stated in the 2012B call for proposals, we anticipate that GNIRS will be available again in December.
13 April 2012
GNIRS was remounted on the telescope last night and is now being used for science with the peripheral wavefront sensor. Unusual vibrations continue to affect image quality with Altair, and work continues to understand the problem.
02 April 2012
Still working on the cooling system. We hope to be back on the sky around April 12th, but this depends on receiving parts from the mainland in time. After that, GNIRS and NIRI may alternate on the telescope as vibrations from GNIRS' cold heads affected AO performance last time GNIRS was mounted. This depends on the performance observed once GNIRS is back, though.
08 March 2012
The recent GNIRS cooling system issues are now known to have been caused by a shipment of contaminated helium. A warmup will start tomorrow in order to avoid potential damage to the cold heads. We expect that GNIRS will be out of use for two weeks, most of which is the time required to warm and cool the instrument. Due to a prolonged spell of poor weather on Mauna Kea, very little GNIRS spectroscopy has been obtained since the previous round of engineering work.
02 March 2012
GNIRS is cold again and being used for science observations. While the cooling performance and temperature are now close to normal, some fairly small instabilities remain. If further work on the instrument and cooling system turn out to be necessary, it will be announced here.
13 February 2012
GNIRS is currently being warmed up for work on the cold heads, whose performance started to deteriorate this weekend. As it takes several days to warm and cool GNIRS, we expect that the instrument will be unavailable for about 2 weeks. Details of Gemini-N instrument configurations and availability are updated daily and can be found on this web page.
1 February 2012
GNIRS has been used routinely for queue and classical observations at Gemini North for over a year now. The OT library and many of the web pages have been updated based on the experiences of the GNIRS support team and GNIRS users in the community over that time. The latest version of the Gemini IRAF package also contains a number of bug fixes and improvements. User feedback continues to be welcome. Recently, the Gemini Science and Technology Advisory Committee recommended that GNIRS be opened for maintenance and improvements during the second half of 2012. More details about that work will be made available as the planning progresses.
2 February 2011
The automatic wavelength calibration task (nsappwave) in the new version of the GNIRS DR package fails to work on some data. An updated version of the nsprepare task, which will fix this problem, will be released shortly. Users are encouraged to contact us via the helpdesk for assistance in the meantime.
13 January 2011
The data reduction software needed by GNIRS North PIs is now available to download. Science data reduction with the software has been evaluated for a limited subset of GNIRS' many observing modes, and this should be considered a preliminary, "beta" version of the package. User feedback on the software and its documentation is encouraged.
22 December 2010
System Verification programs are being observed during normal queue observing, as are some 2010B NIRI spectroscopy programs that have been converted to GNIRS. However, poor weather during the second half of December in Hawaii has severely restricted observations. Unfortunately the unsettled weather is currently expected to continue for at least another week. GNIRS will remain on the telescope January 11; it will be back in mid-February. In general GNIRS is behaving as expected; however there has been a significant increase in the rate of occurrence and magnitude of spurious "electronic patterns" appearing on the output data. A python script that effectively removes most or all of the pattern has been developed. Information on this and other current GNIRS problems and issues is available.
19 November 2010
PIs of System Verification proposals were notified about the status of their proposals on November 13. The proposals that have been accepted for SV are listed here.
10 November 2010
The decisions on SV proposals have been delayed until the end of this week (Nov 12). Water ice absorption is indeed no longer present in the spectroscopic optical path in GNIRS. Thus we believe that the entire L band (2.8-4.2µm) will be available for science.
1 November 2010
A total of 43 proposals requesting nearly 300 hours of System Verification time were received. The oversubscription factor is at least 2.5 (given that the weather during the SV time probably will not be good all of the time). We intend to inform PIs of the decisions regarding their proposals on November 10. Meanwhile, in the lab at the summit, GNIRS has been flushed with N2 gas multiple times and also has been warmed while being pumped - all in an attempt to remove H2O, which likes to adhere to surfaces. Vacuum pumping now results in a much lower pressure in the instrument than prior to previous coolings in Hawaii. Thus we are optimistic that there will be much less 3 water-ice absorption in the optical path than previously. Cooling of the instrument begins this week and we expect to know the answer in the following week.
4 October 2010
Gemini is now accepting proposals for GNIRS System Verification. Twelve nights are nominally available, nominally eight near the end of Semester 2010B and four near the beginning of Semester 2011A. The deadline for proposal submission is October 25 at midnight, Hawaii time. Guidelines are given in the call for proposals.
23 September 2010
The current phase of GNIRS commissioning has been completed and GNIRS is being removed from the telescope today. Problems with the cooling system prevented GNIRS from reaching its optimum operating temperature during the September commissioning period; however the instrument was cold enough that all commissioning tasks not involving further sensitivity tests were done. The most important findings from the September on-telescope tests are: (1) GNIRS+LGSAO is viable and straightforward, and should produce the same data quality as GNIRS+NGSAO; (2) when using AO the 10 l/mm grating appears to be the cause of the additional degradation of spectroscopic image quality over and above that seen in GNIRS' imaging mode (see the 30 August update below); the degradation is not present or is only marginally present with the other two gratings.
During the next two months Gemini engineers will replace the problematic cooling heads on GNIRS and, once warm, the dewar will be pumped on for a long period of time in an attempt to remove remnant water vapor that condensed on cold optics and prevented observations at 2.8-3.2µm in August and September. It has been decided that all "invasive" engineering (e.g., rotating the detector, exchanging some of the camera lenses that have radioactive AR coatings with newly acquired non-radioactive replacements) will be deferred to mid-2011. The principal tasks for the science team in the next two months are to continue to characterize and understand the commissioning data, provide information to the Data Processing and Development group to allow the GNIRS data reduction package to be implemented, update the OT Library so that it is ready for PhaseII file creation in December, and advertise, prepare for, and begin carrying out the System Verification (SV) process. SV observations will likely take place between early December 2010 and late March 2011.
30 August 2010
Further analysis of commissioning data has shown the best achieved spectral FWHM to be approx. 0.15" (adaptive optics), 0.45" (JHK natural seeing) and 0.35" (LM natural seeing) in excellent seeing. This is not as good as expected given the weather conditions (IQ20) and the performance of the GNIRS optics as measured using arc lamp spectra through the internal pinhole mask. We have identified several lines of investigation, which will be pursued when the instrument is cold again. The IQ in acquisition images has been somewhat better than in the spectroscopic modes (typically ~0.12" with AO and ~0.35 - 0.4" with the short cameras in very good seeing), so slit losses are not expected to be excessive. At this time we encourage prospective users to be conservative when writing their proposals, and not assume IQ better than stated above.
27 August 2010
On the night of 23 August the GNIRS decker drive became stuck; attempts on August 24 to move it were unsuccessful. On 25 August the engineers began warming up the instrument. The plan is to make a rapid repair of the drive and re-cool the instrument so that commissioning can continue before GNIRS is removed from the telescope on September 21 for more extensive engineering work in October and November.
The decker failure occurred prior to testing GNIRS with laser guide star adaptive optics (LGSAO) and prior to our understanding and perhaps achieving the best possible performance with NGSAO. Consequently, if AO is offered in 2011A it may limited to NGSAO and the promised performance, in particular image quality, may be conservative.
22 August 2010
The second period of on-telescope nighttime commissioning began on 16 August and is proceeding well. The GNIRS Science Team is well on its way to commissioning almost all observing modes that do not use the OIWFS, including all gratings and cameras, NGSAO (natural guide star adaptive optics), and (hopefully later this week) LGSAO (laser guide star adaptive optics). Assuming that things continue to go well, GNIRS will be offered in Semester 2011A in many observing modes. In addition, should things continue to go well GNIRS will be offered to the PI's of NIRI 2010B spectroscopy programs in Bands 1, 2, and 3. GNIRS will not be used for poor weather programs in 2010B.
GNIRS problem areas identified to date are as follows.
- The decker drive continues to get stuck occasionally. Should this situation worsen it will be necessary to warm up the instrument.
- The internal mirror used for acquisition does not go into position reproducibly. Until this is fixed it will result in longer acquisition times for placing targets in slits.
- Flexure and long-term guiding accuracy, as well as the ability to perform accurate blind offsets (e.g., to very faint targets) have yet to be fully evaluated and fully tested.
- Because of problems and long time delays in procuring camera lenses with durable non-radioactive coatings, GNIRS is currently outfitted with its original lenses which have radioactive coatings. These lenses, and in particular the ones in the short focal length cameras, produce considerable numbers of spikes on the detector array, covering typically 3x3 pixels.
- Water-ice has condensed on one or more optical elements in the instrument and is absorbing all incoming light in the wavelength range 2.80-3.25 microns. It renders the short wavelength portion of the L band unusable.
- The detector is tilted by approximately 1 degree, which results in lines of constant wavelength being tilted on the array by the same amount.
It is currently expected that GNIRS will be warmed up in mid September and that at least some of these problems will be addressed, before it is cooled down and put back on the telescope in late November.
The GNIRS ITC (integration time calculator) is undergoing modifications and, although usable, is not fully tested. See the caveat at the top of the ITC webpage. We expect that the ITC will be fully tested and accurate for use on September 1.
28 July 2010
The first phase of on-telescope commissioning of GNIRS took place during July 16-22. All indications are that the instrument performed approximately as expected in its non-AO mode. Sensitivity measurements based on observations of stars,with integration times ranging from a few minutes to about 30 minutes, indicate that the instrument is very close to meeting the predictions of the ITC. More rigorous tests of sensitivity will be made during the second commissioning run, which likely will begin on or about August 9. The performance in AO (NGS) mode also will be tested thoroughly then (only preliminary tests with AO have been made so far, with no show-stoppers found). The only major concern with the mechanisms is with the decker drive, which got stuck occasionally during the first commissioning phase. If it and all other mechanisms continue to work, we expect that the August commissioning will demonstrate that the instrument is performing satisfactorily at all wavelengths and resolutions, with and without AO. If so, the instrument will be offered in the normal manner for queue science in Semester 2011A, with System Verification science observations also solicited following the August commissioning and probably scheduled in the middle of Semester 2010B.
8 July 2010
GNIRS has been transported to Mauna Kea and currently is sitting on the Gemini North observing floor. The instrument passed its acceptance tests in early June, but administrative issues, mostly related to obtaining insurance, resulted in a delay in transporting it to the summit.
It is currently expected that cooling will begin tomorrow or on the weekend, and that on-telescope commissioning will commence on July 16. A ~2 week down-time for unrelated engineering work on Gemini North will begin on or about July 21; commissioning will pause then. The first stage of commissioning, prior to the shutdown, will concentrate on the basics of getting everything working and testing acquisition, nodding, spatial and spectral image quality, and obtaining an initial estimate of sensitivity. Commissioning will resume on or about August 5. The goal remains to obtain sufficient information about the (hopefully excellent) performance of GNIRS by late August to offer it in Semester 2011A in many of what we expect will be the most popular observing modes (including NGS AO).
27 May 2010
The third cold cycle of GNIRS is nearly completed. The thermal short and vacuum leak were repaired and the detector temperature is stable at 28.0 K, believed to be at or close to the optimum operating temperature. In most respects GNIRS is operating very well. Although there remains much to do to understand and optimize performance and to integrate the instrument with the telescope, there appear to be be no show stoppers to making GNIRS available to the community soon. GNIRS is scheduled to begin formal acceptance testing next week. The plan thereafter is to warm up the instrument, prepare for shipping, transport it to the telescope, reassemble it, cool down, and to complete the acceptance tests and begin on-telescope commissioning during a two week period beginning on about July 6. A second commissioning period is likely to take place in late August or September. The intention remains to advertise the instrument in September for Semester 2011A in a limited number of observing modes and to undertake System Verification science observations late in Semester 2010B. Because of the difficulty and long delay (hopefully now nearing an end) in procuring reliable replacement lenses with non-radioactive coatings, GNIRS will be operated at least for the next few months and probably into 2011A with old spare lenses that have radioactive coatings; these are likely to cause considerable number of spikes in data that are obtained using the short focal length cameras.
23 April 2010
The second cold test of GNIRS in Hilo took place during the first two weeks of April. The most notable new accomplishments were the demonstration that the OIWFS detector and the science detector are now confocal and the completion of flexure tests for both detectors. Those data are currently being analyzed. The cold tests were limited due to (1) a thermal short in GNIRS which resulted in an elevated (by ~20K) science detector temperature and (2) a vacuum leak. As far as we can determine the science detector and all four cameras are performing as expected but much more rigorous tests will be needed during the ensuing cold test cycle, now scheduled to start in early May. Because of the need for this third cold-cycle in Hilo, the on-telescope commissioning has been moved back and will start no earlier than June 23.
19 March 2010
Reassembly of GNIRS is under way; it was delayed by problems with other Gemini instrument that required considerable effort by engineering staff. It is currently expected that the second period of cold tests, lasting ~3 weeks, will begin around April 1. If all goes well the instrument will be mounted on the telescope on 3 June and 80 hours of on-sky commissioning will take place during 3-23 June.
16 February 2010
Optical realignment of the OIWFS optics is proceeding. The position of the detector is being moved in x and y to put it better on axis and in z so that it and the science detector can be remotely adjusted to be confocal, which was not possible during the first cold test. In addition the thermal coupling of of the OIWFS detector is being improved. The current engineering schedule has the second cold test in Hilo starting approximately the second week of March. The science team currently is planning the testing that it will carry out while the instrument is cold.
1 February 2010
In November-December 2009, GNIRS underwent its first cold tests in the Gemini laboratory at Hilo. Three of the four cameras, all of the gratings and cross-dispersed prisms, and all filters were functional. An engineering grade array was used. The performance of the instrument was generally good. In particular the image quality and spectral resolution are improved over the instrument's previous performance. Flexure of the optics associated only with spectroscopy is at a satisfactorily low level; unfortunately it was impossible to determine whether the additional flexure that was observed is associated with the mounting of the external light source or the GNIRS fore-optics. Initial tests of the OIWFS were promising but showed that further optical alignment is required. Some of the cameras contained old optics with radioactive AR coatings, which we anticipate will be replaced by non-radioactive versions in the future. Procurement of these new optics continues to be a concern.
The next cold test is scheduled for March in Hilo. It is planned that the science grade array will be installed, that working versions of all four cameras will be installed, and that improvements to the OIWFS will be completed. Numerous small engineering tasks will also have been completed by then.
Currently, GNIRS is scheduled for the first stage of re-commissioning on the Gemini North Telescope in June 2010. Although GNIRS will not be offered for normal queue and classical observing in 2010B, it is expected to be offered for Science Verification observations during the latter part of the 2010B. To that end a special call for proposals would be issued early in 2010B. Potential applicants for SV science should continue to monitor this space.
Previous News Items
11 June 2009
The completion of the repair of GNIRS has been further set back, mainly by ongoing problems with the stability of anti-reflection coatings on some of the replacement optics. System Verification is now planned for Semester 2010A. Potential applicants for SV science should continue to monitor this space.
A science grade detector for GNIRS has been identified and is being purchased.
16 February 2009
The completion of the repairs to GNIRS has been modestly set back largely by recent degradations of a few critical optical components and delays in the delivery of a few repaired and replacement optics. As of 2009 February it is expected that following lab tests of GNIRS in mid-Semester 2009A, on-telescope re-commissioning of GNIRS on Gemini North will begin in the final 1-2 months of Semester 2009A. Assuming this proceeds well, there will be a call early in Semester 2009B for GNIRS System Verification proposals; it is expected that approximately two weeks of Gemini North time in 2009B will be devoted to successful proposals.
Status of GNIRS as of June 2008.
The following news items contain information about the overheating incident which has led to GNIRS being temporarily removed from use:
15 May 2007
Further details on recovery plan
14 May 2007
Recovering from the GNIRS overheating incident
12 Dec 2005
Upgrade Results, New Instrument Scientist and Other News
During 3rd quarter 2005, GNIRS underwent major servicing, including replacement of the thorium-coated lenses on the short camera that produced radiation events on the detector, installation of a broader and more sensitive cross-dispersed filter and two additional narrowband filters for acquisition.
7 Dec 2004
NGO Phase II and Status Update for 2005A
2 Jan 2004
Announcement of System Verification Opportunities for first GNIRS modes sent to National Offices.
12 Dec 2003
GNIRS mounted on side port 5 on Gemini-South telescope and sees first twilight [image]
3 Nov 2003
GNIRS is unpacked on Cerro Pachon [image]
24 Oct 2003
GNIRS leaves NOAO Tucson after successful completion of pre-ship Acceptance testing [image]
