The Ohio State University College of Mathematical & Physical Sciences Department of Astronomy

Attendees: Pat Osmer, Bruce Atwood, Darren DePoy, Tom O'Brien, Mark Derwent, Paul Byard, Jerry Mason, Dave Steinbrecher, Dave Brewer, Dan Pappalardo, Ed Teiga, Andy Krygier, Kristy Scheckelhof, Carrie Klingel, Jen Marshall (via video from LBT), & Rick Pogge

The MODS1 work plan has finished update, and is now on the wall between Jerry and Dan's office in full Gantt-chart glory. Current plan shows completion of MODS1 in mid-2006 (roughly 20 months), with MODS2 following about 18 months later in late-2007.

In compiling the work plan, we have identified some new hires that will be required to meet our human resources needs:

1. Programmer - already advertised, job ad closes Oct 3, will then select and interview candidates in mid-October, to hire as soon as we can get someone. This is a full-time position backed by hard money

2. Junior mechanical engineer, an ad is being prepared. It is envisioned as a 3+year term position.

3. Electronics Technician primarily to assist Bruce on the detector systems. Bruce and Darren are tasked with coming up with the job requirements and creating the ad. This is also envisioned as a term appointment, duration TBD.

4. Postdoc - an Ad is out in the AAS with a December deadline for the David G. Price Postdoctoral Fellowship, with a focus on developing the MODS multislit capability. We are seeking a postdoc with MOS experience for a 3-year term.

To enable plan management and effor tracking, we have instituted a system of weekly progress reports. Each Wednesday all tema members will be given their progress report forms, to be completed and into the office by the end of the day of Friday to a mailbox designated for this purpose. Kristy Scheckelhof in the office is tasked with collecting reports as the "project administrator".

Kristy will collate the reports and send them to Jerry and Mark who will analyze the results. They then report to Darren who will evaluate any changes or issues that arise. Once this is done, the new data will be re-entered into the work plan to track progress and recalculate the schedule and remaining work estimates. This should allow us to quickly identify emergent problem areas and be able to move resources to cover those needs before problems grow into crises.

Darren is proposing a slight reorganization of the lab personnel to better facilitate communications among the main project areas, and establish clear lines of communication, especially for potentially conflicting areas of resource demand (e.g., the machinists can work on a number of areas: mechanical, electronic, and detectors). An org chart is being prepared to illustrate these changes.

Paul is waiting for a detailed map of the dings/craters on the blue camera corrector lens parent, and a full report from SOML on the accident.

Tom has basically finished the AGW camera stage design, and is making excellent progress on preparing the bid package for the machining.

Mark is making excellent progress on the design of the calibration tower. An emergent issue is that we need to work out the collision detection and avoidance procedures, as the Calibration Tower and AGW Camera Stage encroach on each other's volumes. We are exploring both hardware and software restrictions.

The MODS structure is now complete (see picture below), and is awaiting finally buffing and painting. The collimator truss tubes and frame will be painted flat black, while the upper frame will be neutral gray primer as we still have some additional work to do on that for mounting most of the MODS components. We will likely bring it to the campus shop in first quarter of 2005 when we have space for it in the lab once aluminizing fully clears out and we are ready to start working with it.

2004 September 16: Completed MODS1 structure and its handling cart awaiting cleaning and painting (Photo by Indian Creek Fabricators)

Rick reported on a series of recent videocons between Potsdam, Heidelberg, OSU, and LBTPO regarding the first-generation AGW cameras. To summarize, these are cameras built on the Steward Observatory guider design. They use E2V CCD57-10 512x1024 frame-transfer CCDs, ARC (aka "Leach SDSU") Gen-2 controllers (actually a hybrid Gen 2 and 3 system), and run the Steward-provided AzCam software on a Windows XP system provided with the fiber I/O board. We have had one of these cameras since mid January in the lab (though it is currently in storage as we had to make room for all the aluminizing stuff that came back from Rickenbacker).

The programming team at Heidelberg has been tasked with developing the Guider Control System (GCS) for the LBT. In prototyping their system with one of the other Steward cameras and AzCam software, they found that images could only be read out and transferred at a cadence of 1-2 seconds (0.5-1 Hz), but the original specification was always understood to be 10Hz. No amount of binning, region-of-interest, or other tricks were able to squeeze more than a 1Hz cadence out of the camera/software.

The history of the 10Hz spec is that it is a "guestimate" by John Hill and Piero Salinari given the natural frequency of the telescope structure (about 3-4Hz, we'll know this experimentally by December or so), and considering the case where 2 guiders are working in parallel, one on each primary, where you can expect correlations between motions due to shake/vibration. The spec was for 10Hz windowed to a small region of interest, not full-frame 512x512.

In any event, Mike Lesser reported at the last AGW videocon that he has some new software that will allow more rapid readout and data transfer, using a raw binary format instead of FITS (the latter has a high overhead due to the way AzCam has implemented the FITS generation). He has it working at ~60Hz using just software (no readout), and will send out software and ROM upgrades to implement it on the field cameras. Hopefully the Heidelberg guys will have an answer for us soon regarding the improvement in performance with an actual camera. In all, the recent spate of focused videocons has helped better open the lines of communications between the teams and LBTO/Steward, and we're making progress on resolving them.

Also, we've learned a few things about the current status of the LBTO's procurement of AGW cameras that are of potential concern to the MODS project.

Thus far, six (6) camera units have been purchased by the project and assembled in Steward Observatory's detector lab by Mike Lesser. These cameras all use Gen-III ARC controllers, two of which were purchased by the PEPSI team, the remaining 4 were purchased by AIP for the AGW units. The first camera has been at Potsdam for the last year or so, and uses an older generation controller and software, while the remaining 5 use the current controlers. One of these was shipped to OSU for MODS in January, two are in Germany: one at the AIP in Potsdam and one on loan to Heidelberg for use by the GCS team developing the control software, and the remaining two are at Steward awaiting installation of microlens arrays that will turn them into the first pair of slow off-axis Wavefront Sensor (WFS) cameras. The first two WFS cameras will be shipped to Potsdam for integration into the first two AGW units they are building (these are to be used at the bent inner focus with LUCIFER). The first Potsdam camera with the old controller will be sent back to Steward to receive a new controller and presumably to have a third lenslet array bonded to it to make it the third WFS camera, completing the suite.

These are reportedly the last of the ARC/Leach controller cameras to be built for the project. All subsequent cameras will likely be of a new design based on the Magellan camera, but using a 16-bit readout board that is currently in the prototyping stage (the current Magellan camera is 14-bit?). Current Mike Lesser's lab is looking for vendors to fabricate and stuff the circuit boards. So far the prototype system looks good, but it is delivering 10e- readout noise instead of the 2e- of the ARC controller. He says that if we required 2e- readout noise, that would pretty much require an ARC controller.

The initial package of cameras that the LBT project has now is essentially 3 pairs, each consisting of a guide and WFS camera (collectively called the "AGW Cameras"), the first two pairs of which are earmarked for the LUCIFER AGW units. The pair currently earmarked for MODS will be "borrowing" the PEPSI-purchased controllers for the time being. This brings up the question of when the "final" MODS1 and MODS2 camera pairs will be created, and in what form - this has impacts primarily on software used to drive them (which may be different than the GCS being developed for the ARC controller cameras), and possible some hardware issues regarding what boxes are mounted where to control them (the dewars will be the same mechanically, so don't impact the mounting design in our AGW camera stage for MODS).

Mike Lesser is currently setting up to create a 16-bit version of the Magellan controller (rather than an Gen3 ARC controller), and presumably the final MODS cameras for deployment at LBT will be of this type. We don't, however, seem to have a clear read on this. Thus we have some questions for the project:

1. What is the status of the MODS AGW camera pairs? Mark Wagner was posed this question at the last AGW videocon, and is finding out for us.

2. When can we expect delivery of these cameras, and what is the schedule impact for integration, testing, and commissioning of MODS1 and MODS2? In particular, how long do we actually get to keep what are apparently the PEPSI cameras?

3. Why the 16-bit modification of the Magellan camera system required, since the current 14-bit(?) version has the considerable virtue that it is known to work very well at both Magellan telescopes playing the same role it would play at LBT? What is this requirement based on?