Volume 5 Issue 6 Late Fall / Winter November / December 2003

Equipment Review: Orion 80mm ED Refractor by Lawrence Carlino

Amateur astronomers have long realized the virtues of the classic refracting telescope - an instrument capable of superb definition, high-contrast imaging, and exceptional versatility. With no central obstruc- tion in the optical path, the refractor has the potential of yielding the finest definition of any telescope type - if it were not for the demons of . The classic 2-element Fraunhofer objective can reduce this spurious color to manageable levels, but only in cumbersome long focal ratios of f/15 or above. The use of special ED (extra low dispersion) glass or calcium fluorite in one of the lens ele- ments, or a three or four-element design, solves the problem and allows much more convenient focal ra- tios. But the cost of such a system ranges from pricey to prohibitive, even in the smaller . Happily, this situation may have changed with the introduction of Orion's new 80mm ED refractor tube assembly. Utilizing one element crafted from FPL-53 fluorite glass, the scope sports a clear of 80mm and a focal ratio of f/7.5, yielding a focal length of 600mm. Made by Synta in China and imported by Orion, this instrument is by far the lowest -priced apochromatic (false-color-free) refractor available in its aperture range. At $429 + shipping, the ED 80 comes with a 2-inch Crayford focuser , 1.25" adapter, a Table Of Contents nicely finished dark gray metallic aluminum tube, a detachable dew cap, plastic dust cap, and a mounting block with 1/4-20 female threads for attachment to a variety of mounts and tripods. Tube mounting rings, President’s Message star diagonal, and eyepieces are all optional extras. A built-in dovetail "shoe," however, will accommo- Page 2 date any of Orion's finder scopes ranging from 6x26 to 9x50mm. Overall, the telescope's fit and finish appears to be very good with no glaring defects or evidence of sloppy workmanship. Weighing in at a Meeting Notices svelte 5.7 pounds, the whole OTA is 24 inches long, but it can be truncated to 19" with the dew cap re- Page 3 moved in order to allow airline "carry on" portability.

Member News Clearly, the ED 80 has the potential of being a real bargain - if it performs! The main question here lies in Page 3 the scope's optical quality and degree of color correction. Is it really an ? That is, is false color reduced to levels where it is essentially absent, even at high magnification on objects that are notori- Observatory News ous for exhibiting purple fringing with less-than-perfect optics? Does the definition and image sharpness Page 3 even begin to approach the standards of excellence set by the superb instruments of Takahashi, Astro- Physics, and TeleVue? Fortunately, I was able to do some comparisons with telescopes of comparable Editor’s Note aperture in a direct "A- B shootout" and from recent experience with a number of other refractors. Page 4 With both the moon and Mars favorably placed for critical observation, I put the ED 80 through its paces Membership Corner in seeing conditions ranging from vile to reasonably steady. As is typical with small, high-quality refrac- Page 4 tors, poor seeing conditions still permit some satisfying low and medium-power observation. Here, the scope did not disappoint as it yielded some sharp, high-contrast images of the waxing gibbous moon at BAA Annuals magnifications of 46 and 66x. Absolutely no false color could be seen on the lunar rim, with the TeleVue Page 5 9 and 13mm Type 6 Naglers providing an almost 3-D effect. When the air steadied, a 5mm Orthoscopic (120x) revealed fine detail in and around Copernicus, a neatly defined Straight Wall, and a cratered lunar Member’s Pictures south that resembled a smaller-scale spacecraft glimpse of the rugged surface. Very impressive, and quite Page 8 similar to the images generated by my fine Takahashi Sky 90 APO, but with somewhat less brightness.

For Sale Mars was also a pleasant surprise. At 158x under fairly steady skies, the ED 80 easily displayed the Page 12 shrinking south polar cap, the more prominent dark markings such as Syrtis Major, Sinus Sabaeus and Meridiani, the slight Martian phase effect past opposition, and an occasional limb haze. Again, false color was a non-issue, and the scope functioned beautifully with contrast enhancement filters (#21 orange) in bringing out additional detail. The blue halo so typical of even a good achromat was completely missing. Based on past experience and some direct comparison, I would rate this performance as slightly superior to that of the fine Borg 76 ED refractor, equal to the TeleVue 76, and just a touch behind the magnificent Takahashi 78mm Fluorite, arguably the best in this aperture range.

Double stars also proved to be a revelation with the ED 80, as it performed well beyond expectations. Epsilon Lyrae, seemingly almost everyone's classic test of optical quality, was cleanly resolved at powers as low as 66x. At 120 and 158x, the hard, sharp, color-free airy disks of the four component stars were strikingly apparent, the clean, dark sky between showing a thin, perfectly symmetrical first diffraction ring. Throwing the image out of focus produced just a slight tinge of color and no trace of spherical aber- ration or astigmatism. As a rough guess from this performance, I'd rate the overall optical correction of (Continued on page 4) Page 2 The Spectrum Volume 5 Issue 6

BAA OFFICERS UB TELESCOPE PROJECT President—Joe Orzechowski Peter Proulx BAA Web Site Phone: 632-7091 Vice President—Dr. Jack Mack ROBOTIC SCOPE PROJECT Tom Bemus and Bill Smith put together a club web site at : Phone: 632-6210 Anthony Davoli http://www.upstateastro.org/stars/baa.html Secretary—Peter Proulx Phone: STAR PARTIES Treasurer—Bev Orzechowski Jeff Gardner Phone: 632-7091 SPEAKERS MEMBERS AT LARGE Dr. Jack Mack Janice Gardner Meetings Tom Bakowski SPECTRUM STAFF Alan Friedman Editor —Jamie Seibert BAA meetings are held on the 2nd Friday of the month from September to Phone: 689-3349 June in the New Science Building on the Buffalo State College Campus. COLLEGE OF FELLOWS E-Mail: [email protected] Meetings start at 7:30 pm and all members and guest are encouraged to attend. Rowland Rupp Phone: 839-1842

OBSERVATORY DIRECTORS Bill Aquino 731-9366 Paul Tabor 434 7148 Spectrum Deadline

MEMBERSHIP DIRECTORS Articles for the next Spectrum will be due by: Tristan Dilapo 941-5613 Alan Friedman 881-4310 December 12th 2003

President’s Message by Joe Orzechowski

With Thanksgiving just around the corner, I thought it would be appro- night. You also gave members and visitors the opportunity to look priate to take this opportunity to express my thanks to all those who through and examine a bunch of different equipment, making it possible have helped keep the BAA running and doing what it's suppose to do for us to continue to publicize this as one of the benefits provided by the and who have made my job as president a lot easier. Because there are BAA. so many of you I won't mention names for fear that I will unintention- My thanks also go out to our membership directors for keeping track of ally omit some of you. who's who and who paid for what. Having held the position myself for a couple of years I know the amount of work involved in keeping the I'd like to thank the board members and officers who served with me last BAA's membership rolls (which were significantly smaller back then). year and those who have taken up the challenge for the coming year. An honorable mention must also go out to the membership directors at These folks are ultimately responsible for keeping the BAA running this time of year as they finish up the daunting task of processing renew- and, while they certainly don't do all of the work, they are the ones who als for 150 members. make the often easy but sometimes not-so-easy decisions about what should be done and what should not. Any complaints? Talk to an at- Of course, none of us would be reading this or any of the other articles large board member or BAA officer…that's what we're here for. Aside in the Spectrum if it wasn't for our editor. This is one of the most diffi- from giving of their time, board members have often had to deal with cult positions to fill because it does entail a considerable amount of my lack of sufficient notice about upcoming meetings. For their toler- work and talent. We should all be grateful that we have someone who is ance, I am grateful. willing to spend time collecting, organizing and publishing our written words in a professional looking newsletter. The Beaver Meadow Observatory is a major center of BAA activities and it is no small feat to keep that facility and all of its equipment oper- Thanks also go out to those people who helped out with our special ating properly and to maintain our advertised public night schedule. events and projects. I know that quite a few people have volunteered While thanks must go to our observatory directors, many thanks are also their time and money to getting the robot telescope project and the UB due to all those who make the long drive down to BMO to help out with data link up and running. And the wonderful thing is that most of them public nights and with maintenance projects. These folks come out to will be continuing their efforts to expand the capabilities of both of these upgrade and repair the observatory, keep the computers running, ensure systems. Thanks must also go to those who help with our annual March that the telescopes are in decent working condition, give presentations to dinner meeting, our holiday party at the December meeting, Astronomy the public, run the BAA's scopes or bring their own scopes for public Day, and various special events at BMO, the Buffalo Museum of Sci- nights. During the recent Mars opposition those of you who brought ence and other venues around western New York. your own scopes helped save the day on more than one crowded public (Continued on page 3)

MEETING CANCELLATION POLICY If, for any reason, (most likely snow or ice storms), there might be cause for cancellation REPRODUCTION NOTICE of the meetings of the B.A.A., tune your radio to either WBEN (930) or WGR (550). Also “The SPECTRUM” is the official newsletter of the Buffalo Astronomical Association, if Buffalo State College has been closed due to inclement weather, so will the meeting of Inc. Permission is hereby granted to any non-profit astronomical society, to reprint, in the B.A.A be cancelled. whole or in part, any article in this, or any other issue of “The SPECTRUM”, provided BEAVER MEADOW TELEPHONE credit is due this newsletter, the Buffalo Astronomical Association, Inc., date of issue and The telephone at Beaver Meadow, 716-457-3104, is for emergency use only at no cost. author of said article. Local calls may be placed for a small charge - see the collection box by the phone. This phone cannot make long distance calls. Page 3 The Spectrum Volume 5 Issue 6

Meeting Notices

November 14, 2003 – Mars Exploration Rovers Marilou Bebak will be speaking on the Mars Exploration Rovers (MER) mission. The twin rovers, Spirit and Opportunity, were recently launched to the red planet and are scheduled to arrive on Mars early next year. Come to the November meeting and hear what NASA hopes to accomplish with these new and improved rovers.

December 12, 2003 – Holiday Party and Roast Join in the festivities as we start off another holiday season. Edith Geiger will once again entertain us with her slides of strange sightings and go- ings on at various BAA events during the past year. If you were lucky(?) enough to attract the attention of her camera lens, you may be a part of this good natured roast of some of our members. The usual food and beverages will be available afterwards for all to enjoy.

Member News

On October 10th 2003, Mark Reville passed away in Mercy Hospital, South Buffalo. Mark had been operated on for a brain tumor the week before our September meeting, and when I went to visit him on Friday and mentioned I was thinking of going to the meeting, he said, "I'll go with you." That was after just getting out of the hospital that morning. Some of you saw us down front on the left, but after I finished my presentation he told me we had to leave. On Monday 10/6, he fell at home and lost consciousness and was taken to Mercy and placed on Hospice. I visited him Tues-Thursday and told him I'd be up Sunday after I got back in town from a commitment. He passed away the following morning.

Mark loved astronomy, and the members of the BAA. We spent many evenings driving to the BMO observatory, Griffiths Sculpture Park, Per- rysburg searching for clear skies to set up his 18" Dobsonian or use the club's 20 ". The morning we shared together for the meteor storm will remain with me always. We all will miss his crazy humor and open friendships to all. Clear skies, Mark.

Observatory News by Bill Aquino As of the time of this writing we have just one public night left in the Hohman. Clear skies and great observing. We had a VERY large public 2003 season. However, by the time this issue of the Spectrum is pub- crowd of 400+ show up to view Mars. lished and distributed the public night season will be over. Once again it was a great year for public night activities and we were exceptionally September 20th Public Night Volunteers included Pete Proulx, Elliott busy at the observatory on August 16th and September 6th thanks in large McKinley, Joe Orzechowski, Ted Jackson, Ted Bistany, Rowland Rupp, part to the close approach of Mars. The club members who helped out Bill Aquino, Alan Friedman, Scott Smith, Bob Hughes, Paul Tabor. with public night activities throughout the year once again did a great Clear skies and great observing. job. Thank you very much. October 4th Public Night Volunteers included Ted Jackson, Alan The observatory is now closed to the public and “non-checked-out” Friedman, Ted Bistany, Paul Tabor, Bill Aquino. Cold and rainy so no members but does remain open and available to all members who are observing. checked out. If you are not checked out and want to be, see one of the observatory directors during next years public night season (April This year the observatory needed a fresh coat of paint. Our first painting through October 2004) so we can begin the process, it takes a month or work party took place on the afternoon of September 6th (prior to public two. During the winter months we will be concentrating on telescope night) and included, Tom Bakowski, Rick Pason, Ted Jackson, and maintenance activities. This very important work is done by small Alan Friedman. Thanks guys for doing a great job. groups of volunteers on an informal schedule. A special thank you needs to be given to Ted Jackson for repairing the Special Thanks leaky roof at the observatory. Thank you Ted. Need to be extended to public night volunteers as well as work party volunteers. Thanks for helping out. Also, thanks to Bob Titran for donating a very special book to the clubs library, Planetary Observing by Fred Price. Fred is a long time BAA September 9th Public Night Volunteers included Paul Tabor, Anthony member and his book is an excellent and detailed guide to the demand- Davoli, Rick Pason, Tom Frank, Alan Friedman, Tom Bakowski, Gary ing art of planetary observing. Flagg, Ted Jackson, Jeff Gardner, Bill Aquino, Dennis and Colleen

(Continued from President page 2) terested in astronomy. You, the members, are who I was describing in the opening paragraph as "all those who have helped keep the BAA Finally, I'd like to thank all those who have joined the BAA or who have running and doing what it's suppose to do." We are giving people the renewed their membership this past year. This may seem like a cheesy chance to hear about things in which they have an interest and to see way of getting everyone on my "Thank You" list but I am quite sincere things they might otherwise never see. And don't underestimate the im- in my gratitude to each and every member because you are the BAA. pact we have on public night visitors. Just come out to the observatory Let's face it, without members there would be no need for a board of on a clear public night and listen to the reactions we get when someone directors or an observatory and there would be no one to receive the gets their first look at the Moon or the rings of Saturn or the Double Spectrum. Every time you pay your dues you are voting "Yes" for as- Cluster. I'm certain that these people are grateful to you as well. tronomy, voting "Yes" for what the BAA does to help those people in- Page 4 The Spectrum Volume 5 Issue 6

Membership Corner This was the summer of Mars. BAA telescopes offered fine views of the red planet to thousands this summer (when the clouds finally parted)– at Beaver Meadow Observatory, at Buffalo State and at star parties around Western NY. I have never seen the lines so long and the public so jazzed about an astronomical happening. If everyone only knew that they will see it even closer in 2287…

Perhaps this is why we have a passel of new BAA members to welcome this fall. Dan Galland, Kevin Kavanagh, Chris Geelan, Michael Lewandowski, Ted Jackson, Dan Krakowski and Janet and Dick Zehr joined the BAA during the summer months.

If you have let membership dues slip your mind – there is still time to send it in and not miss an issue of the Spectrum. And don’t forget that the deadline for discounted subscriptions to Sky and Telescope and Astronomy magazines is October 31st.

Printed copies of the BAA membership directory are available from Tristan – and I have produced an electronic version. Give us a call or send an email if you would like a copy.

Clear skies!

Alan Friedman/ 881-4310 Tristan Dilapo/ 941-5613 [email protected]

Editor’s Note I thought I might share some personal news with you: As some of you know, my wife and I recently became the proud parents to a happy, healthy baby boy. Dennis James Seibert III was born on Sept. 19th becoming one of our newest and youngest BAA members. While we are experiencing some sleepless nights, our days are filled with joy and amazement as we watch him grow and we can’t wait to show him the skies in the years to come.

(Continued from page 1) William Optics Megrez scopes are another story altogether. They actu- something on the order of 1/8 wave - very good by any standard. ally cost a bit more than the ED 80, but they are beautifully built and finished. Their optics resolve as well as the APO's, but their achromat or More challenging multiples such as Epsilson Bootis, Iota Cass, Zeta semi-APO designs introduce significant false color at medium magnifi- Aquarii, and Alpha Herculis were resolved without difficulty. The real cations and above. The much more expensive TeleVue 76mm APO excitement came, however, when I attempted to nail Delta Cygni, nor- provides image quality quite similar to that of the ED 80, but the pre- mally a test object for a quality 4-inch scope. With a huge magnitude mium price tag buys the owner superb fit and finish along with a feel of difference and tight separation, this binary was a long shot at best. Yet, lasting solidity. These other choices may well fit the requirements of at 120x under steady skies, I found the tiny companion nestled unmis- many observers but, overall, the new Orion offering stands apart as the takably in the primary's first diffraction ring. The "NO way!" I ex- optimum combination of price, optical quality, and design. claimed spontaneously probably startled neighbors within a half-mile radius. As good as the ED 80 is, it does have a few minor shortcomings. Bal- ance is sometimes difficult to achieve with the center-mounted 1/4-20 Deep-sky performance of the ED 80 is naturally compromised by its block. The scope is tail-heavy, especially with a 2-inch star diagonal in modest aperture, but the near 100 percent light throughput of the APO place. Presumably, the mounting block can be removed and repositioned design, lens multi-coatings, and lack of a central obstruction combined rearward, but that would involve drilling into the tube. A better solution to permit some very pleasing views. Using a 2-inch star diagonal and is to obtain the Orion 100mm hinged tube rings ($17.95/ pair) and elimi- ultra-wide-angle 30mm BW Optik eyepiece, the scope generated a 4- nate the problem altogether. In addition, the Crayford focuser provided, degree field-of-view that encompassed the entirety of M 31 and its satel- despite its wonderfully smooth feel, does exhibit minor backlash at lite galaxies. Contrast and field darkness were excellent, attesting to the times when drawtube tension is dialed up, and the focuser cannot be effectivenes of the scope's internal baffles and lens coatings. The completely locked down for astrophotography or electronic imaging. Pleiades were also a striking sight in this configuration. At higher pow- ers, the ED 80 proved capable of resolving Hercules' M 13 into a hand- These are insignificant annoyances in light of the extraordinary value ful of tiny stars, and the more open M 22 was resolved completely. M the ED 80 represents. The telescope ushers in a whole new era of af- 57, the famous Ring Nebula, revealed its true shape and the nearby 13.0 fordability for the highly-desired APO design, and I suspect that Orion magnitude star - not bad at all for a small telescope in a semi-rural loca- will have a difficult time keeping the instrument in stock. One can only tion. hope that larger Orion , say in the 100 to 125mm aperture range, are in the works for sale at comparable bargain prices. That Invariably, many will ask how the ED 80 compares to the ubiquitous would have refractor enthusiasts almost everywhere dancing in the small achromats on the market, as the price ranges begins to overlap. streets. Certainly, the performance of this APO far outshines that of Orion's own Short Tube 80 and 90mm achromats. They display an abundance of Clear skies! false color and severely limited potential for high-resolution lunar and planetary viewing - but they are less expensive. Even the Orion 100mm Astroview f/6 achromat is thoroughly outclassed. The Stellarvue and Page 5 The Spectrum Volume 5 Issue 6

BAA Annals by Rowland A. Rupp 5 YEARS AGO - "Choosing and Using a Telescope" was the topic for our November 1998 meeting. Larry Carlino and Joe Orzechowski explained to newcomers to the BAA and to members of the general public about the properties and choices of telescopes. Edith Geiger did her annual "Candid Camera" program as an appetizer preceding our December Christmas party. Two proposals, passed by the Board of Directors, were brought before the membership for approval. One was to adopt a new club logo designed by Gene Witkowski; the other was to add the posi- tion of Spectrum editor to the Board. Both were approved by the membership. Thanks went to Bill Aquino, Dan Marcus, Gene Witkowski, Jeff Gardner, Neil Dennis, Tim Leary, Frank Chalupka, Anthony Davoli and Rick Pason for repairing the observatory roof. Fred Price and Rowland Rupp both submitted separate approaches to determine how much of the sun is obscured during an eclipse - a project that resulted from a star party discussion at Lime Lake earlier in the year. Their equations differed because their starting points differed, but the results were the same. Steve Kramer contributed to the solution as well. How to find Messier 101 in 10 seconds (!?) was described by Bill Smith, while Helina Biernacki discussed some of the ancient rituals that were based on astronomical events. An observation report by Frank Chalupka, Bill Aquino and Dan Marcus, and a of BAA members who attended Starfest that past August appeared in The Spectrum. 10 YEARS AGO - "The Moon" was the topic for November 1993. A number of short talks were planned, but speakers' names were not given. Slides on the universe (whatever that might entail) and Edith were the highlights for December. It was announced that our May dinner meeting would be held in March, as it has been ever since. President Bill Smith thanked many members (too many to list) who had worked on the newly finished addition to BMO, and also to those who had contributed, one way or another, to the 20-inch Dobsonian telescope from Obsession now housed there. Leslie Martin wrote on the "Origin of the Nebular Theory of Planetary Formation", and Edith Geiger did a profile on the club's Secretary, Luann Szucs. Bill Smith reported on a star party held at BMO during which the new roof for the observatory was completed. 15 YEARS AGO - In November 1988, the University of Toronto's Philip Kronberg spoke on how super computers aid in making astro- nomical discoveries. For December, Darwin Christy let us in on where he gets all that information on ancient constellations that he works up into Spectrum articles. Ernst Both showed us photos taken by Walter Semerau of solar activity, and Edith finished off with another episode of "Candid Camera". President Doris Koestler announced that Dan Marcus had been appointed Observatory Director and Diane Borowski was our new Mem- bership Director. Dan wrote an "Observatory Report" in which he discussed some of the issues at BMO and his plans for its future. Darwin Christy wrote an article on the. Magellanic Clouds; Ed Lindberg reported on the activities of the Instrument Section. Tristan Di- lapo's book report was on "The Universe in Your Backyard" by David Eicher. It is a collection of articles previously published in Astronomy magazine. Tristan highly approved of it. Marilou Bebak reported a turnout of 600 people at the museum's Kellogg Observatory to view the favor- able opposition of Mars. There were sketches by Fred Price of observations he made of the planet. Carl Milazzo also submitted an observation report. 25 YEARS AGO - In November 1978 we held a nostalgic meeting at our old haunt, the Museum of Science, where Ernst Both, then Curator of Astronomy, spoke on a favorite topic of his - Mars. Edith's "Candid Camera" and the Christmas party were featured for the following month. A BAA Study Section, headed by new member Torn Giosomo, was being organized. I guess study sections are a thing of the past now that we have the Internet. Fred Price's sketches of Jupiter appeared in The Spectrum, as did a brief article by him suggesting that most of the large scale features on the moon, and perhaps on Mercury and Mars as well, were of internal origin. Edith Geiger wrote a profile of Tom Dessert, our first BMO director. Tom also served as a club officer, was a member of the College of Fellows and an ardent astrophotographer. 35 YEARS AGO - Fred Price, BAA President in November 1968, spoke on the "Norman J. Lockwood Observatory". In December, Ed and Olga Lindberg were scheduled to speak on Tycho Brahe, just before Edith was to give her annual photo event and we were to retire to Christmas festivities. There were articles by Dale Hankil:l on "Barker's Quadrangle in Mare Crisium" and by Kurt Erland (I know who he really is) on "The Future of Canadian Astronomy". Kurt lamented the cancellation of a 150-inch telescope intended to be erected on Mt. Kobau in southern British Colum- bia. An obituary for John Riggs Sr. appeared in The Spectrum.

Where Are We? by Mike O’Connor WHERE ARE WE? DETERMINING THE “EXACT” LOCATION OF THE ROBOTIC TELESCOPE AT THE BEAVER MEADOW OBSERVATORY

Anyone who has ever bought a telescope, car or computer knows that as time marches on, so too do advancements in technology.

In December, 2000 Bill Aquino and I authored an article that was published in The Spectrum about observing occultation’s from the Beaver Meadow Observatory. In that article we detailed our efforts to determine the exact coordinates of several observing sites at the Beaver Meadow Observatory using a handheld Magellan Model 315 GPS receiver. Using the average of values manually recorded from the Magellan 315, we determined the pier for the 10” LX200 to be located at 42° 40’ 21.9” N, 78° 23’ 2.7” W and at an elevation of 1514 feet above sea level.

We compared those results with values gathered from other sources which included the value already posted at the BMO observatory, one from an internet website, and one from a measurement carefully taken from a topographical map. We concluded that confidence in our measurements was quite high and recommended that club members use these values for BMO's geographic position, at least until someone could come up with values having a higher level of confidence.

(Continued on page 6) Page 6 The Spectrum Volume 5 Issue 6

(Continued from page 5) Using SA Watch proved to be quite simple. After the GPS receiver is Since that article was originally published there has been a major ad- connected to the computer’s serial port, SA Watch continuously moni- vancement in GPS receiver technology – the widespread availability tors and records the data generated by it, thereby greatly simplifying and of low cost WAAS-enabled GPS receivers. automating the data collection process which was previously done by hand with my Magellan 315. SA Watch also graphically displays the Given that I recently added a WAAS capable GPS receiver to my collec- weighted mean of the points recorded in real time on the computer tion of instruments (my wife calls them “toys”), I wanted to compare the monitor, and, using the weighted mean of the points, generates a lat/lon results that Bill and I generated nearly three years ago with a non- reference point with a positional accuracy to within one meter. WAAS GPS receiver with those from my new Garmin GPS 16 to see if I could "come up with values having a higher level of confidence". This article details my findings. THE “EXACT” LOCATION OF THE ROBOTIC TELESCOPE

Armed with my Garmin GPS 16 and SA Watch installed on my WHAT IS WAAS? laptop, I set out one recent Sunday morning to determine the “exact” WAAS is an acronym for “Wide Area Augmentation System”. It is a location of the robotic telescope at the Beaver Meadow Observatory. system of GPS satellites and ground stations that provide GPS signal I gathered data with the GPS antenna located on the top of the struc- corrections, enabling WAAS-compatible receivers to provide up to five ture housing the 10” LX200 so as to maximize the antenna’s view of times better positional accuracy than older units. the horizon, an important factor in optimizing GPS performance. The plot screen of the Garmin GPS16 generated by SA Watch during WAAS consists of approximately 25 ground reference stations posi- this test is shown in Figure 1. During the test period 2,140 data points tioned across the United States that monitor GPS satellite data. Two were collected and mapped. As Figure 1 clearly demonstrates, there was master stations, located on either coast, collect data from the reference very little scatter of the data points, with only a few of the data points stations and create a GPS correction message. This correction accounts falling outside of the 2.5 meter circle. None of the data points fell out- for GPS satellite orbit and clock drift plus signal delays caused by the side of or even came close to the 5 meter circle. The tight mapping indi- atmosphere and ionosphere. The corrected differential message is then cates a good field of view of the satellites, good satellite geometry with broadcast through one of two geostationary satellites. The information is a resulting high degree of confidence in the accuracy of the data. compatible with the basic GPS signal structure, which means any WAAS-enabled GPS receiver can read the signal.

To illustrate how far GPS technology has advanced in just a short time, consider that the accuracy of the original GPS system, which was subject to accuracy degradation under the government-imposed Selec- tive Availability (SA) program, was 100 meters. Typical GPS position accuracy when SA was shut off by the government on May 2, 2000 improved to 15 meters.

Now, WAAS-capable receivers can provide a typi- cal positional accuracy of less than three meters, which is well within the 30 foot positional accuracy required by IOTA for occultation timings.

USING SA WATCH

In addition to the use of a WAAS-enabled GPS receiver for this study, I was also able to take ad- vantage of computer software called “SA Watch”, a $20 shareware program available for download from http://huntting.com/sawatch/index.html .

SA Watch was originally written to monitor and analyze the apparent wandering that a GPS receiver did despite actually Figure 1 remaining at a fixed location. At the time the program was written, these wanderings were largely due to SA. Since May 2, 2000 when SA was removed, however, we can now use SA Watch to monitor positional Figure 2 is a report generated by SA Watch containing an analysis of the error caused by other factors such as ionosphere and troposphere delays, data samples that it has collected, with minimum, maximum and mean signal multipath, receiver clock errors, ephemeris errors, the number of satellites visible and satellite geometry/shading. values reported for latitude, longitude and elevation. From Figure 2 we

(Continued on page 7) Page 7 The Spectrum Volume 5 Issue 6

(Continued from page 6) What conclusions can be drawn from these results? First, the new learn that the robotic telescope is located at 42° 40’ 21.82” N, 78° 23’ WAAS-enabled GPS receivers live up to their reputation and can pro- 2.77” W and at an elevation of 461.8 meters or 1515.092 feet above sea vide very accurate positional information in a relatively short amount of level. time. Second, the shortcomings of non-WAAS enabled GPS receivers can be overcome by long term averaging as is demonstrated by the nearly identical results obtained by both the WAAS-enabled receiver and by averaging the data points generated by the older Magellan 315.

Third, and lastly, we have further confirmation that the results obtained in our initial studies remain valid. As a result, it is my recommendation that club members use the following slightly refined values for BMO's geographic position:

42° 40’ 21.82” N 78° 23’ 2.77” W

461.8 m/1515.092 ft.

Is this the “exact” location of the robotic scope? Probably not ex- actly, but it is accurate to within at least three meters, if not less. Further refinement, if necessary or desired, will have to wait for additional advancements in technology. Figure 2

HOW DOES WAAS MEASURE UP?

Figure 3 is a chart comparing the results obtained with the WAAS- enabled Garmin GPS16 with those generated in our earlier study. Of particular interest is the fact that the resulting values for the location of the robotic telescope differ by only .08" latitude, .07" longitude and 1 foot in altitude (one tenth [0.1] of a degree of latitude or longitude equals 10 feet).

Figure 3

Source Latitude (degrees) Longitude (degrees) Altitude (feet)

Robotic Scope 42° 40’ 21.82” 78° 23’ 2.77” 1515.092 (new) 10” LX200 42° 40’ 21.9” 78° 23’ 2.7” 1514 (old) Posted at 42° 40’ 20.0” 78° 23’ 7.5” Not available BMO Topographical map 42° 40’ 30.4” 78° 23’ 4.9” 1508

From internet 42° 40’ 22.0” 78° 23’ 2.0” Not available website

Page 8 The Spectrum Volume 5 Issue 6

Member’s Pictures

Above: Chromosphere by Alan Friedman

Below Left: Fun with Mars by Dennis Hohman Below Right: Mars Revisited by Dennis Hohman Page 9 The Spectrum Volume 5 Issue 6

Member’s Pictures

Left: M13 by Alan Friedman

Below: Humbolt by Mike O’Connor Page 10 The Spectrum Volume 5 Issue 6

Member’s Pictures

Above: M31 by Anthony Davoli

Left: Saturn by Alan Friedman For Sale

Meade Finderscope 6x30 Sky Window Binocular Mount. Like New $20 $175 Great Condition. Orion 9x50 Right Angle Allows you to observe with binos without cranking your neck. Finderscope Contact Rick Fusani at 868-2077. $45.00 Call Ralph Green at 649-5911 Meade 125mm Astro Aluminum tripod, Electronic Controller OMCON 80mm (Model 708) f/7 refractor complete with diagonal, $400 20 mm plossl eyepiece, *equatorial mount and tripod (EQ2). It has Jay Bowden 877-7959 been used perhaps 8 times and is in mint condition. Asking price is: $225 or b/o. If interested contact Don French at: 691-2187 week- days after 7 PM. I have purchased a 90mm ETX-RA and do not FOR SALE need a second scope. 4mm Televue Radian eyepiece *Note: in process of moving, the counterweight and rod attaching 60* AFOV / 20mm eye relief. Perfect condition. to mount were lost. Counterweight with attaching rod is available $175. Interested? from Orion for $35.00 to include shipping and is reflected in the Contact Tom Bakowski asking price of $225.00 (still a bargain!!). Any questions let me 662-6910 or know. [email protected]

Newsletter of the Buffalo Astronomical Association Inc.

Jamie Seibert 958 Robin Rd. Amherst, NY 14228