Happy people

Telescope Installation

With the building complete, the time had come to install the telescope. Arriving early on a Wednesday morning, whole crews of people came to be a part of the event: the crane operator, the contractor, architect, videographers, students and more!  It is not often that one gets to see such a large telescope lowered onto its pier using a crane. Below is a photo journal of that day’s events as well as the following day during which PlaneWave’s engineer, Matt Dieterich, and I spent the day wiring the systems and testing the electronics.

Initial pier inspection

Brian Carmody and Matt Dieterich begin the initial inspection of the dome and pier prior to getting the installation started.

The telescope arrives on a flatbed

The CDK700 telescope arrives on a flatbed from the storage facility. The crane and operator has already arrived, so things are about to get busy!


The various telescope components were then uncrated while on the truck.

Tethering the telescope's mount and primary mirror assembly to be hoisted.

Tethering the telescope’s mount and primary mirror assembly to be hoisted. It was at about this point that everyone’s heart rate went up a little!

The telescope is airborne

The telescope is now airborne, taking a short ride from the truck to the pier within the dome.

Enroute to the dome

With some serious expertise, the telescope was guided gently to the dome.

Slipping into the dome

The telescope being lowered through the dome’s shutter. While Matt (and everyone) looks on.

Sunrise with telescope into dome

The sunrise continues while the telescope is gently lowered to the three bolts that will hold it onto the pier.

Slowly, slowly, slowly. Using tag lines, the telescope is kept from swaying or rotating as it is lowered into the dome.

lowered within the dome

The telescope had to be lowered onto the three pier bolts. Tolerances were to the millimeter!

The telescope’s mount holes aligned perfectly with the pier bolts. Everyone breathed a sigh of relief at the exact moment when the scope landed onto the levelling bolts.

Secondary Mirror Assembly craned in

Now it was time to repeat this whole process with the secondary mirror cage and assembly.

Secondary arrives in place

The secondary mirror arrives in place and is bolted to the telescope.

The telescope's control system

Next to install was the telescope’s control system which feeds power, reads encoders and sends commands back and forth through a neat intranet system.

Components within

The many components within the control box.

Initial collimation

Using a laser mounted onto one of the two Nasmyth focal points, Matt begins initial collimation of the three mirrors. The corrected Dall-Kirkham optical design uses an elliptical primary, a spherical secondary and a flat tertiary mirror.

Many wires!

The many wires routed from the telescope’s interior, to the control box and to the control room computer.

Wires to be connected at the mount

Those same wires, this time a view from the base of the telescope mount. Within the mount are USB hubs, power supplies, and encoder systems. All must be wired correctly to allow proper control and to prevent twisting as the telescope moves in azimuth.

The pirmary CCD and filter wheel installed

The primary instrument will be an FLI CCD imager with a 10-place filter wheel, seen here at focal port #1 attached to the electronic focuser/de-rotator. All of these components are remotely controlled. 

Happy people

Brian, Matt and John: three happy and very tired telescope installers. The end of two days of work. Next steps? Clear skies to collimate and focus the telescope then build a pointing model.


Installation time

The 0.70m Imaging Train

The soon-to-be-installed 0.70m telescope will not have provision for eyepice viewing. Instead, telescopes of this size usually have an imaging system for collecting image data, among other instruments attached.  This telescope will have tow primary instruments attached at its two focal points: an imaging CCD and a fiver-fed spectrograph.

The imaging CCD will be a Finger Lakes Instruments (FLI) PL16803 4096×4096 9μm pixel array (16.8 megapixel array) with an attached 10-place filter wheel system.  The CCD is a non-antiblooming gate (NABG) system and is linear for most of its efficiency range. Below is a plot of its quantum efficiency. Given that it cooler can get 55ºC below ambient temperatures, we’ll be operating well below freezing every night, even in the summer. This means less thermal noise and clearer images with better data.

FLI CCD Imager

FLI CCD Imager right out of the box.

The filter wheel is a ten-place system, holding 10x50mm square filters for astronomical imaging. In this installation we’ll be using the system mostly for photometric and astrometric work, so the following filters have been installed:

  • Luminance: a clear filter.
  • Hα: Narrow band Hydrogen filter.
  • OIII: Oxygen narrow band filter.
  • SII: Sulfur narrowband filter.
  • g’2: The Sloan (SDSS) g photometric filter.
  • r’2: The Sloan r photometric filter.
  • B: Johnson/Cousins B photometric filter (Blue).
  • V: Johnson/Cousins V photometric filter (Green/Visual).
  • Rc: Johnson/Cousins Rc photometric filter (Red).
  • One empty filter position just in case 🙂
FLI CFW-3-10

The FLI CFW-3-10 filter wheel ready to accept filters and the CCD imager.

The CCD bolts right onto the filter wheel, then the whole assembly is attached to the focal plane of the telescope. All of this is controlled remotely using imaging software, in this case MaxIm DL and ASCOM.

Installing all this requires good lighting, a relatively dust free environment, small tools and some time.

Filters in their packaging

The color filters in their packaging, ready to be installed.

Installation time

Equipment at the ready: it’s time to install the filters.

With clean-room gloves on, each filter is removed from its packaging, then placed into the correct slot with the filter wheel. Two small plastic retainers are then screwed into place to hold the filter wheel in place. The lovely part of this system’s design is that the filters can be installed without removing the filter wheel’s cover. Many others on the market require complete disassembly – not fun.

Should you be interested, some external Links: