FAQs (Frequently Asked Questions) about our new CCDDOP (Charge-Coupled-Device Digitized Observing Program) for Students and Teachers

What is the CCDDOP?

Hardware and software that enables users at remote locations to acquire images of areas of the night sky, via Internet, to survey objects in deep space and perform quantitative research.

What is the primary goal of CCDDOP?

To give students and teachers exposure to doing real science, that is, making observations. Users will take, record, and analyze the data and draw conclusions. That is what scientists do, what science is all about, collections of data, not textbook "facts". This is real data from the real Universe, with all the accompanying error factors, uncertainties, and potential observing challenges from hardware, software, observer, and Mother Nature.

Is this the full remote control telescope operation that was being proposed several years ago?

No, this is a small scale pilot program, designed to evaluate the performance of many phases of remote educational observing, including the hardware, software, usage, and outcomes. The CCD camera is moderate sized, it is "piggybacked" (rides the telescope for aiming and tracking, doesn't view through the telescope) instead of at prime focus, is wide field rather than high magnification, and the telescope still needs to be aimed manually by an operator on-site. The key innovation is availability of data essentially immediately to the user, with opportunity for the user to actually take the picture himself/herself.

Who runs the CCDDOP operation?

Pine Mountain Observatory (PMO) is owned and operated by the University of Oregon. The Director of PMO and originator of the Electronic Universe concept is Professor of Physics, Dr. Greg Bothun, 541-346-2569, The K-12 outreach, development of the specfics of this pilot program, and the administration/acquisition of images are done by the Friends of Pine Mountain Observatory, the citizens' volunteer support group of amateur astronomers/professional educators/technicians. Rick Kang, 541-683-1381,, performs the classroom outreach and has spearheaded the efforts to get the CCDDOP hardware/software/system on-line and is the prime contact person regarding the CCDDOP operation..

How can CCDDOP be used for my class? (two modes)

You can request an image or a series of images of a particular object or series of objects (guidelines: no more than 3 objects/request, one request per week per class, example: Nebula M42, Galaxy NGC253, Jupiter and its moons). The images should be available, weather permitting, within seven days maximum from your request. Please be careful that your targets are indeed up in the night sky that week (consult star charts and/or Rick).

Alternatively, given the constraints as outlined below, you can request a one-hour observing block of time for your class, where students can take their own pictures by remotely controlling the CCD Camera via the Internet, and saving the images from their local screen. This is planned for Tuesday evenings, from darkness to midnight, September through the first part of November, weather permitting. Again, be aware of the hours of total darkness and what objects are visible. Submit your request via E-mail to Rick, indicating at least one alternative date and two alternative time slots. Selection of applicants will be based on as wide a geographic and grade level coverage as we can allot, and is totally at the discretion of the telescope operator for that week, probably Rick most of the time. Final decisions rest with the Observatory Director.

Where do I find the archived images and the camera control site on the Web ?

Archived images are on a page at this site. When you are granted direct camera time, you will be sent the address/password/other details for the computer that you will connect to.

What content/concepts preparation do students and teachers need prior to using CCDDOP?

Students and teachers will find Rick's "Technology to Explore Deep Space" one to two hour outreach session very helpful. We will post a synopsis page on this site shortly. Basically, you need to realize that our target objects are very far away, hence the incoming radiation (photons of starlight are literally "few and far between"), hence your target appears very dim. To collect more starlight, you can use a larger collection "dish" (Telescope) and/or collect the photons over a period of time (accumulation..."integration", with a Camera!). The CCD Camera is very efficient at recording those few and far between photons. See below for more details.

Observatories are places that contain Telescopes, Cameras, and the associated technologies to aim those devices at an invisible distant object in the night sky and keep the instruments pointed at that object until enough starlight is collected so that the user sees an image (picture) of the object or has enough data to perform analysis.

Contact Rick to schedule an outreach session.

If you feel comfortable about prepping your students with the concepts of vast distances, light (photons), photo-electric effect, and digitized images, go for it, your class will do fine with CCDDOP. At the Elementary School level, don't worry about the technical stuff, the students will enjoy the pictures and can begin to understand how the pictures are created later on.

At any level, although background astronomy information may be useful and essential under some circumstances, one of the prime goals of CCDDOP is for the students to DISCOVER what is out there. We encourage you to let them explore the images and try to figure out what the images represent. There is always ample background material available through the many Web sites available (see our Net Astronomy Resources link on the main Pine Mountain page).

How are the images created? What is the hardware setup?

The incoming starlight passes through a very small Maksutov reflecting telescope (90 mm aperture). The main purpose of this instrument is to focus an image onto the CCD Chip inside the CCD Camera, so the telescope basically acts like a lens. There is a little magnification effect, too, which was set up to show detail in the wider objects, like galaxies. The CCD Camera is coupled directly to the Maksutov "spotting scope". The Maksutov tube and associated CCD Camera cylinder are clamped within a wooden frame "cradle", similar to what we use in the outreach classroom demonstrations. The cradle is bolted to a metal box that is bolted to the side of the 24" telescope tube at the Observatory, so that the box gives the camera lens a clear view of the sky, just offset from the large main tube of the 24" telescope. Visitors can hence still view visually through both the "finder scope" and the main eyepiece of the 24" telescope, as electronic images are taken of the same object, via the Maksutov/CCD Camera arrangement. The 24" telescope is used basically as a "tracking platform" for the CCD Camera (the 32" telescope's tracking system is still undergoing upgrading and the 15" telescope's tracking system isn't precise enough) to balance the rotation of the Earth over many seconds' or several minutes' time. Hence, also the term, "piggybacked" camera.

What is a CCD (Charge Coupled Device) Camera?

A CCD Camera, not that different than the device used in your home video camera, converts an incoming pattern of light energy (photons) into equivalent pattern of electrical energy, or charge. Einstein discovered this "Photo-Electric Effect" almost a century ago, that when you hit certain materials with light, electricity is induced. In the Camera, there is a small wafer of silicon, about the size of your thumbnail. This is the CCD CHIP, upon which the image from the telescope or lens is projected and focussed, say the disc of a planet or the spiral pattern of a galaxy. The chip is divided up into a grid or mosaic of '"wells". Each "well" or "photo-site" is capable of accumulating electrical charge as the site is hit by incoming photons, each "well" is like an individual photo-electric cell or "solar cell". More photons (brigher area of the target projected onto a "well") produces more charge or voltage in that "well", less photons (darker area of the image) produces less charge. In our present camera, the "array size" is about 200x300, hence the 60,000 "photo-sites" (individual detectors of light). After the exposure is completed, the wells contain various amounts of electrical charge, directly proportional to the amount of light that fell into each well. The Camera's electronics, controlled by a computer both on-board the camera and a desktop or laptop unit on a table nearby, rapidly measure and read the electrical charge of each well, translating the charges into voltages (like a voltmeter), then into signal pulses that tell the computer the digital value of each well. The final step is for the computer to recreate the picture by displaying an equivalent mosaic pattern of pixels on the computer screen, where the brighness of each pixel is set to correspond to the value of the incoming data from that photo-site on the CCD Chip. This is just the electronic equivalent of the chemical recording of light in conventional photography.

The major advantages of the CCD are the high quantum efficiency of recording photons (short exposure times hence ease of recording faint, distant objects, linearily of response to light (each pixel's value is directly proportional to the amount of light that fell on it, hence the instrument already acts like a photometer), ability to enhance/analyze digitized data by arithmetic operations, and ease of storing/sending/sharing digitized data files.

How does the 24" telescope fit into the operation? Why isn't the big telescope used to form the image?

As mentioned above, the big 24" telescope is used as the stable tracking and aiming platform for the "piggybacked" CCD Camera. This gives us the ability to aim at faint objects and to track accurately to image these objects over relatively long time exposures.

We intentionally piggybacked the CCD rather than placed it at Cassegrain or Prime Focus of the 24" telescope for several reasons: First, we wanted a wide field for imaging large objects (the 24" offers much smaller fields of view). Second, we felt that aiming would be much easier with the finder and main scope available plus the wide camera field, and in order to promote efficient use of the Camera, we didnt' want to spend hours of your time and ours trying to locate the target. Finally, we wanted to preserve the visual use for the 24", as many visitors come to Pine Mountain Observatory primarily to actually look through a large telescope (even though you can truly "see" much farther into the Universe using a CCD Camera), and we may also be using the 24" for other purposes such as polarimetry or high-speed photometry as various researchers have several pending projects.

How large an area of the sky is imaged, what objects fit well?

The imaging system has a Field of View (FOV) of just about one square degree of sky. This corresponds to four Full Moons, touching, set into a square. This works very well for quite a few galaxies and nebulas, several globular star clusters and several open star clusters and usually holds all four of Jupiter's Galilean moons. The field allows us to locate objects readily and to survey areas of the sky for star counts, presence of nebulas, and objects that display high proper motion.

What objects don't work well for the CCDDOP hardware?

Small (under 10 arcminutes diameter) or large (over one degree diameter)or very bright (over Mag 0) objects will not work well, due to field of veiw of the imaging system, and high efficiency of the camera. In other words, you will not be pleased with images of any of the Planets except to see the positions of Jupiter and its four Galilean moons, most of the planetary nebulas, some of the globular clusters and galaxies (too small), the really sprawling nebulas and galaxies like M31 and the Veil or entire constellations (too big), or the brightest stars/planets/and of course the Moon and Sun (too bright). This still leaves many objects of great interest to image!

What is the typical exposure time to create an image and time to get an image onto the web site?

Due to the high quantum efficiency of the CCD detector, exposures are typically from several minutes for galaxies and nebulas down to fractions of seconds for Jupiter. This means that we can take quite a few images during an observing run and reduces the problem of precision tracking.

The largest amounts of time spent during observations will be in slewing (moving) the telescope to a new target, identifying and centering the target in the FOV, the transfer/download time involved for the camera/analog-digital converter/computer-graphics card to bring the roughly 60,000 bits of data from the CCD chip to the screen, and the conversion process to reformat and post the image onto Internet. Typically, one could expect from 5 to 15 minutes to acquire a new target, depending mostly on how far we need to slew and how dim the object is visually (since we will still be using our finder-scope and main eyepiece to locate/center the object, hence potential difficulties to locate the target), several minutes for the camera system to produce an image (and possible need to adjust exposure/aim/focus and re-take), plus several minutes to convert to GIF/FITS and post to the web site. That is why we are suggesting three images per hour.

What hardware/software do I need to access images? To process (enhance/analyze) images?

You definetely need a computer connected to the Internet, preferably a high-speed (ISDN or T1) Ethernet arrangement. A modem will work but will be very slow and frustrating. Your computer should be running Netscape so that you can view the images and readily copy them to your hard drive. Images will typically be just under 200KB apiece. The GIF format will provide pleasing views and works well with several "slide show" programs like VUIMAGE, but will not allow analysis of the data for photometric use. We recommend Richard Berry's latest release of Astronomical Image Processing (AIP), $30 through Willman-Bell, for DOS based computers, and SkyProbe, by Logos Software (Canada) for MACS, for handling the FITS (Flexible Image Transport System) images.

How do I request images?

E-mail Rick ( with the common name (ex: Jupiter), Messier designation (ex: M42), or NGC number (ex: NGC 253) of your target. Note the restrictions of no more than three objects per request and no more than one request per class per week. We envision that within the first few weeks we will have an archived set of the "common" objects, like M42, so you might want to check our Web Page first to see if you can find a current image already there.

How do I access the digitized images that I request? What format will they be in?

Via WWW (Internet), using a browser such a Netscape, will be the easiest way. Archived images requested will be posted on our CCDDOP Web Page in GIF format for general viewing, since Netscape handles GIF. The CCD Camera produces the raw images in its native Santa Barbara Instrument Group (SBIG) format, which is not usable in terms of Internet transfer and requires the proprietary software to re-open, but fortunately, the camera control software on-site has provision for direct conversion to FITS, and we have on-site software to convert to GIF. We will also build a directory of the same images, in the FITS format. You will be able to use FTP (File Transfer will need to have FTP software on your computer) to transfer the FITS formatted images to your machine. The FITS images will be suitable for analysis such as photometry and detailed astrometry. We may consider also building a directory of raw images still in SBIG format, for users wishing to FTP directly into their own CCDOPS or SKYPRO, etc. software.

What hardware/software do I need to do a live observing session?

You need a program that can control transfer of graphics over the Internet, so that you can not only send commands to the camera, but view the camera control screen and the images. (Telnet works fine to control operations but is unable to handle graphics so will not do for this use). We plan on using software called Timbuktu, marketed by Farallon, based in Oakland, Calif., and available via their web site, or via mail order. We have Timbuktu loaded on our web machine at the 24" telescope, but you also need Timbuktu on your machine (plus, of course the internet TCP/IP software) in order to work with our system. Timbuktu is available for both DOS and MAC platforms. Cost currently is around $70.00 for DOS, and $130 for MAC but we are working with Farallon to see how we can set up some sort of multiple site licensing arrangement to reduce your cost. We'll be glad to help you convince your administrators that this is well worthwhile, but unfortunately we do not currently have funding to buy your software.

How do I schedule live observing sessions?

Initially, due to Rick's present outreach commitments, we will commence with live imaging on Tuesday nights only. E-mail RIck,, at least one week in advance of your selected date. We may modify these criteria, depending on volume of applicants and success of the operation. As mentioned above, the sky must be completely dark and completely clear. Darkness will govern the starting hour, earlier of course as Winter approaches, and we will try to run until midnight, if some older students or some teachers want to stay up that late. You will need to figure phoning PMO several times during an observing session so you need a room with a computer connected to Internet, preferably a high-speed (ISDN or T1 Ethernet link), plus a telephone line. Don't figure being able to do this via modem. You can probably download archived images OK that way, but wait until your school has Ethernet before trying the live imaging. Please remember that this is the initial stage of a pilot program, so we'll bear with your software/hardware glitches if you'll bear with ours.

Is there a charge for CCDDOP? Who can use the program?

Initially, we do not envision a mandatory fee for bona-fide students/teachers at a school computer, signing up for live imaging but we certainly encourage donations. We will see how our costs, contributions, and user counts run, which will determine future fee structures. Since we do have some direct costs associated with this program, such as fuel and meals for telescope operators, we suggest a $10.00 contribution from each classroom requesting our service. Please make your check out to Friends of Pine Mountain Observatory, and mail your check to Friends of Pine Mountain Observatory, P.O. Box 5795, Eugene, Oregon, 97405. Anyone can view our CCDDOP web page and download images, but we will restrict image requests and the live imaging program to bona-fide schools. We may consider special requests from serious amateur astronomers. Telescope/camera operation will be totally at the discretion of the on-site operator, selection of schools and targets will be made by Rick, based on criteria as outlined above, and any arbitrations will be made by Professor Bothun and will be final.

What types of observing projects would be suitable for

Elementary Schoolers:
Survey of objects: Compare various galaxies, nebulas, look at motion of Jupiter's moons.
Examine motions of the sky over time.
Survey distribution of stars over sky
Examine limits of detection

Middle Schoolers:
Survey of objects: Examine objects in more detail
Monitor motion of moons of Jupiter
Compare movements of various objects over time
Look for/monitor asteroids

High Schoolers:
Calculate orbital data of Jupiter's moons, make/verify predictions of locations
Use geometry to estimate distances to galaxies
Perform photometry on variable stars
Search for supernovas

What if the weather is cloudy the night of your scheduled observing run?

We will do our best to reschedule you for a subsequent week, but we cannot guarantee a new slot. This is one of the "occupational hazards" that the professionals (except Hubble Space Telescope) face.

This site maintained by The Friends of Pine Mountain Observatory.
If you have any comments or questions please send them to:
Amy McGrew, WebWeaver, or to Rick Kang, FOPMO Education/Publicity Chair
Last updated 16 February 1997.
All artwork by Amy McGrew. Not to be re-published in any form without permission.