WIYN Observatory

ONE DEGREE IMAGER (ODI) Status Updates

ODI News Roundup: August 2009

First OTA Detectors Delivered

Imaging Technology Labs delivered the first functional Orthogonal Transfer Array (OTA) CCD detectors. These four devices were shipped to the Stargrasp controller group at the Institute for Astronomy (IfA, Hawaii) for extensive testing in their test dewar (see picture below with two detectors mounted). IfA is responsible for the electrical interface between their CCD controller and the detectors, and now they are optimising the voltage levels to run the detectors. Also, the electrical connections and the mechanical interface of the test setup are identical to the ODI design.

The first functional OTA CCD detectors

The first functional OTA CCD detectors

Testing of ODI's first functional OTAs at IfA

Testing of ODI's first functional OTAs at IfA

ODI r ' Filter Delivered

Astronomical observations usually require that light of a well-defined wavelength only is observed, and usually a filter made of coloured glass is inserted into the light beam for this purpose. However, at the size of ODI, no stained glass with the required homogeneity is available. For ODI, and other upcoming wide-field imagers, these filters are based on interference, and are constructed through a series of thin-film coatings on a transparent glass substrate.

The first of the ODI filters was delivered by Barr Associates. Given its high price tag, we kept the filter in its shipping box (see picture) until we will mount it in its final filter holder later this year. This r'-band filter is very impressive, not just for its size (about 42 cm by 42 cm). Its peak transmission is better than 95% with an excellent homogeneity. Taking into account all losses in the instrument and telescope, the efficiency of WIYN & ODI in the r' band will be better than 60% (see transmission curve).

The ODI r'-band filter has arrived

The ODI r'-band filter has arrived

ODI Instrument Support Stackup

For the first time we stacked all components of the instrument support package - from the atmospheric dispersion compensator housing to the focal plane. The maximum run out in parallelism between the focal plane and the reference surface of the ADC housing mount was 25 microns. The error budget for the difference between the imaging surface of the telescope and the ODI focal plane is 20 microns. This means that we achieved an accuracy during the initial fit check that can only be improved by the final alignment of the instrument at the telescope!

The Instrument Support Package with all components stacked together

The Instrument Support Package with all components stacked together

ODI Aspheric Lens Shipped for Coating

Lens 1 of the ODI optical corrector was received in Tucson and is now on its way to Infinite Optics (IO) in California to get its anti-reflection coating. Remember, the second lens (which also serves as the dewar window) has already been returned from IO and is awaiting installation in the instrument. The four prisms for the atmospheric dispersion compensator remain in Tucson for further characterisation before we commit them for the coating process.

AAS June 2009 "Science with the WIYN One Degree Imager (ODI)" Meeting-in-a-Meeting

The partners of WIYN Observatory held a three session "meeting-in-a-meeting" on Tuesday, June 9 and Wednesday, June 10, 2009 at the AAS meeting in Pasadena to educate and engage the astronomical community in planning science with the WIYN One Degree Imager (ODI), which is scheduled for installation on the WIYN 3.5m telescope on Kitt Peak mountain in 2010. Below is a brief description of each session, with links to the speaker presentations (all in pdf format). Please note that there is still an opportunity to participate in the Yale survey (see presentation 231.04).

See the brief overview and full presentations for more information.

Last modified: 23-Sep-2015 14:36:16 MST