Today I finished putting all the pieces together. The cameras and mounts were locked down to their elevation and azimuth angles. The camera mount plate assembly was placed inside the metal enclosure and cables were run to the control computer. After a few small adjustments to a couple of the mounts, the cameras now have clear un-vignetted views out of the window. The image on the left shows all 16 channels (saturated during the day) on the computer display. This was a big step towards first light.
We are working on some final design considerations to deal with two environmental factors: vibrations and potential lightning strikes. To reduce vibrations from wind and a nearby air conditioning unit we are considering placing vibration damping sandwich mounts between the camera mount plate and the enclosure.
Flagstaff sees a good amount of lightning storms, particularly this time of year as the monsoon climate is in full effect. With a metal enclosure, we want to make sure that a lightning strike does not fry our electronics, control computers, or the electrical network in the Slipher building. For the enclosure and electronics on the roof we are taking steps to ensure proper grounding. To protect our control computers, which will be conductively connected to the enclosure via data cables, we will install lightning surge suppressors on each of the RJ45 data cables. To protect the Slipher building in general we will run the power for our cameras through an isolation transformer. Fingers crossed that we don’t happen to run any real world lightning suppression tests.
We surveyed our options on the roof of the Slipher building for exactly where to place the first LO-CAMS station. We settled on building a platform on the edge of this existing walled enclosure. Sight lines are excellent, the cable run for data and power will be relatively short, and the station will be easily visible from the courtyard, which will make it possible for LO-CAMS to be a part of the regular campus tours led by our educators and docents.
Lots of LO-CAMS activity over the past couple of weeks. After looking into a lot of different options for a window on the top of the camera enclosure we eventually found a great solution in Pilkington OptiView glass. This is reinforced, UV blocking and highly anti-reflective. Thanks to Leif Ortegren at Pilkington for helping us find this solution.
We also starting looking in detail into options for mounting the camera boxes at our two sites: Lowell’s main campus in Flagstaff, and out at the site of our Discovery Channel Telescope. Our first station will be deployed on the main campus and it will go on top of the historic Slipher Building, pictured here with the official LO-CAMS mascot. We will likely construct a simple plywood platform for installing the first camera station.
Finally, our metal pegboard arrived which will sit in the box enclosure and serve as the mount plate for the cameras and electronics. This will allow us to assemble the first station into a final configuration.
After looking into a variety of camera enclosure options, we eventually were connected with a local Flagstaff-based company called Artisan Metal Works, who specialize in designing and building a variety of custom welded aluminum parts for whitewater rafting and boating applications, which include water-tight boxes. Nic Ulrich and Tim Quigley at AMW helped design a box enclosure that will protect our cameras and standup to the challenges of the local climate. The first of these boxes arrived today and brought us a big step closer to final assembly.
UPDATE 10 SEPT 2015: Thanks to Diamond Auto Glass who helped affix the window to the top of the box with windshield adhesive. This will definitely hold up for a long while.
Thanks to help from CAMS software guru Dave Samuels, we now have full installations of the AutoCAMS software on our control computers. Dave took several hours of his time to help get the full suite of CAMS capture and image processing software installed and tested on our new computers. This is a well vetted and mature software package that makes LO-CAMS possible — it would have been a massive undertaking to try to develop from scratch a software foundation to control, capture and process the video stream. Instead, with just a few hours of configuring the software we are now ready to record some fireballs!
To figure out the optimal configuration of our cameras, mounts, power supply, switches, and cabling we assembled everything into a mock layout. Laying everything out in a realistic configuration turned out to be very helpful in figuring out the necessary dimensions for the camera enclosure. It is looking like we will be able to fit everything in a box about 2’W x 3’L x 1’H.
Based on the experience of the CAMS team,we know a single computer can be used to capture and process all 16 channels of standard definition video at 30 frames per second. So we set out to build a custom computer for this purpose, with the goal of hitting a price point under $1000. A custom build machine will make it easier to upgrade or replace components in the future. Thanks to input from the IT group at Lowell we met our goal and put together a powerful machine to handle the requirements of our 16 camera stations. We built two machines, one for each LO-CAMS station, with the following specs: 4.0 GHz Intel Core i7 processor, 16 GB of memory, one 128GB solid state drive for running the system software, a pair of hot swappable 2TB SATA drives for data storage, a DVD drive, and two 8-channel Sensoray frame grabber boards.
Dan spent time in the Lowell machine shop this week modifying the L-brackets to work as camera mounts. This image shows the cameras lying on their sides with the dual L-bracket design locked down to fixed elevation angles. These brackets are simply off-the-shelf framing hardware available at essentially any hardware store. The mounts are locked into two different elevation angles — 40 and 66 degrees — which respectively correspond to the angles for the outer and inner ring of cameras. Thanks to Jeff Gehring in the Lowell machine shop for help in completing the mounts.