Sunday, August 10, 2008


Old Go-tos Made New Again

What’s troubling you, Binky? Your once cutting-edge go-to telescope is yesterday’s news? That formerly artful and elegant LX200, Ultima 2000, or Vixen Skysensor doesn’t seem classic? It’s just old? The computer hand control (HC) that once amazed you with its powerful features now reeks of TRS-80 Model I? Believe it or not, there is a cure that doesn’t involve spending a couple of grand on a new mount—or a whole new telescope. There are ways to bring your old warhorse up-to-date, and, if it is otherwise in proper working order, there is really no reason to buy something new.

As you might have suspected, what I am talking about is running your scope from an external computer. I’m sure many of you are doing that already, but even if you’re a full-fledged member of the Rubylith brigade you may not be fully aware of all the options and advantages that come with lodging a computing device on the ol’ observing table. Yeah, it ain’t quite all laptops. I’ve seen planetarium programs running on cell phones and even the Sony Playstation Portable, but when it comes to interfacing to a telescope there are three main paths: laptop computer, NexRemote/EQMOD, or a PDA. Actually, there could be one more—and better—way, but I’ll save my idle fancies for the end.

Until fairly recently, running a scope with a laptop computer usually meant a Windows laptop computer, as there were few software choices for Mac mavens and even fewer for Linux lovers. That has changed of late, with plenty more software becoming available for those “other” operating systems. Even the PC users’ longtime favorite freeware planetarium, Cartes du Ciel is up and running (in beta form) under both Apple OSX and Linux.

I occasionally hear the owners of the most recent Macintoshes, those with Intel processors, assert that they can run all the Win software they want via a Windows partition on their hard drives. Maybe. Oh, I have no doubt that most Win astroware will run in this fashion, but there is a catch. If you want to do more than just use the program as a computerized star atlas, you will have to connect it to a scope, and that’s where problems usually crop up in the Mac/Win game. Not to say you might not be successful, but my advice? If you have a Mac, buy Mac software—there’s plenty of good stuff out there now. You also have to decide which kind of software you’re gonna run. No, I ain’t talking “TheSky or Starry Night?”—a roundup of specific astro-softs is a subject for a future article—but which variety.

As the years have rolled on, adding gray hair after gray hair to Unk’s pore head, astronomy software has divided itself into two broad classes: planetariums and planners. Planetariums, which are what most of us think of when we think “astroware,” put a computerized depiction of the sky on your computer’s screen. Representatives of this sort of soft are TheSky, Starry Night, Cartes, Megastar and many more. Using various tools, you’ll locate objects on this “silicon sky,” retrieve information about ‘em, and send the telescope to them.

The look of the faux sky that is home to all them NGCs varies from program to program. Some strive for the ultimate in realism; maybe even a beautiful representation of the heavens composed of actual images. Others have remained cartoonier, with constellations being represented by dots and lines and deep sky objects by little symbols. Both types have something to recommend them. We all like purty stuff, and a “pretty planetarium” like Starry Night Pro Plus can do a great job of showing the appearance and extent of deep sky objects. On the other hand, at three o’clock in the a.m., I tend to find one of these masterpieces hard to decipher, and prefer dots and symbols instead.

The second species of astroware? The “planning” programs. At first they are a mite-off-putting. Instead of a fancy rendition of the heavens, what you get when you boot one o’ these puppies is something a lot like what you see when you start up Microsoft’s Access: a database. Oh, most offer some level of sky charts, but don’t expect Starry Night’s virtual sky. Ho-hum, right? It’s a ho-hummer? Sorta-maybe. These softs, programs like SkyTools, Deepsky, and Astroplanner can actually be more helpful for working observers than the planetariums.

The thing that makes ‘em so valuable is that they allow you to organize your observing. Ever been outside with the scope unprepared and wondering what you oughta look at? Chances are you couldn’t quite decide, so you observed a couple of bright Messiers and called it a night. The planners allow you to assemble observing lists from their extensive libraries of objects (in most cases something on the order of 500,000 to 1 million DSOs). Most also offer scads of ready made lists; you’ll never be left standing under a beautiful sky stumped as to what you oughta look at. Assemble a list, click on an entry, and the scope goes there, one DSO after anudder.

Of course, before you can send the old scope on its way with either type of software, before you can "upgrade" it to the 100s of thousands of object in the computer program, you’ll need to hook PC to telescope. At the simplest level, that requires only a few things you won’t already have in your gadget box. The most important being the cable that connects scope and computer. That is almost always a serial cable—Meade did experiment with USB connectivity with its line of RCX scopes, but those appear to be goin’ the way of the dodo. Where do you get such a cable? You make or buy. If you’re handy with a soldering iron and an RJ crimping tool, building one is the labor of half an hour.

Since the various telescope makers use slightly different protocols and never (don’t ask why) use standard RS-232 cables, make sure you put together one appropriate for your scope. A good source of plans for Celestron cables is Mike Swanson’s Nexstar Site. Got a Meade? That “other” Mike, Mike Weasner of Mighty ETX fame, has cable plans on his site. Don’t feel too confident about your soldering talents? Scope serial cables are inexpensive and available from almost all dealers.

Before computer will talk to telescope you may have to purchase one additional item, a USB – Serial converter cable. Since most laptop computer makers have stopped furnishing serial ports on their machines, you’ll have to add one. That is done with one of these inexpensive little cords (BestBuy or your electronics emporium of choice should have ‘em). Plug the serial cable coming from the scope into one end of the USB – serial converter, insert the other end into a USB port, and you are good to go. Well, usually. Some go-to users have reported problems with telescope communications using these USB – serial adapters. Most often that is only the case with advanced programs like EQMOD and NexRemote, but if you’re worried about it, buy a Keyspan USB - Serial converter cable. It will work with the most demanding software.

There’s another item you may have to glom onto before you can get your Win PC and scope chatting: software. I don’t mean the planetarium program or planner; I mean ASCOM. Whether you will need ASCOM or not depends on the astro-program you are using. “What the hail is ASCOM, Uncle Rod?” In order for a computer to talk to a telescope, it needs a driver for that particular brand and model of scope. The situation is no different from what you encounter when trying to make a PC talk to a printer. Unfortunately, Windows does not have any telescope drivers built into it, so you will have to bring your own.

How? Some Windows programs like TheSky and Megastar come with built-in drivers for a selection of popular scope models. If that is the case, you just hook everything up (with scope and computer power off, natch), select your scope model and go. Other astrowares rely on another program, the aforementioned ASCOM (Astronomy Common Object Model), a freeware application, to provide drivers and act as an intermediary between telescope and computer. Cartes du Ciel, SkyTools, and Starry Night are some programs that use ASCOM for scope interfacing.

Which is better, built-in or ASCOM? I prefer ASCOM. Yes, having to download and install a second program is a bit of a bother, but the results are worth it. Not only does ASCOM do a masterful job of running a telescope from a PC, often providing features like a virtual hand pad for slewing that built-in-driver programs don’t; it also supports many more telescope models than any built-in-style program does. Chances are, any go-to telescope (or digital setting circle computer) old or new has had an ASCOM driver written for it. ASCOM can also do other cool stuff like control observatory domes and operate motorized focusers. Once ASCOM is set up, it’s no more difficult to connect to the scope with it than it is with a built-in driver. The planetarium or planner you’re using will have a “connect to scope” button or menu selection. Mash that and here comes ASCOM. Select and configure your scope in the windows it throws up and you are ready to have some fun.

“OK, so scope is connected to computer. What good is that and how does it help provide new features for owners of aged go-tos? Being able to click on an object on a planetarium program’s display or a planner’s observing list is cool, yeah, but why is that really better than just using the ol’ HC?” One improvement is the number of objects you can go-to. An older scope may be limited to the NGC and IC. About 12,000 objects, that is. The typical planetarium or planner will “give” your old machine instant access to 1,000,000 or more. Yeah, I know most of us will probably never exhaust the NGC/IC, but number of objects is only part of the advantage to having a program’s huge library available. There is also the variety of catalogs. What if you’re a confirmed open cluster fanatic? You love cruising the Milky Way for cool little Berkeley and Lynga clusters. Or maybe you’re a planetary nebula boffin hooked on the PKs. Good luck finding these catalogs and objects in your 1990s hand paddle. Almost any astro-soft, however, will have ‘em and tons more, besides. Want a PK? Click on it and send the scope to it. No more searching for alternate IDs or entering RA and declination coordinates.

Not only does a PC program offer far, far more objects than an HC, it holds much more extensive information about said objects. Yes, if you’ve got a NexStar or an Autostar, you can access some scrolling data about some DSOs, but this will be limited to Just-the-Facts-M’am: size, distance, type, and magnitude. What if you’re curious, say, about a globular cluster’s Shapley – Sawyer type? You won’t find that in your old (or even new) HC, but it will likely be given in the extensive info most programs have on file. Usually, accessing this information is as simple as right-clicking on an object and selecting “details,” “about,” or “information.”

Other reasons? Software may be able to add features, important features, your telescope does not possess. Owners of older Celestrons, for example, lack “sync.” This function allows you to center an object that was “off” after a go-to, press a button, and have all subsequent targets (at least in this particular area of the sky) fall into the field of view; usually near the center. Sync can be a big help for scopes that occasionally miss objects. That doesn’t help Ultima 2000 owners or users of all but the latest NexStars, however, as sync is not available in their hand controls. No need to bemoan that fact or spend lots of time mashing slew buttons chasing errant DSOs, though. ASCOM and some built-in-driver programs, offer an “outboard” sync feature that works every bit as well as that found in modern hand controls.

Planetariums and planners are cool. But there is Another Way, laptop programs that replace the telescope’s hand control, NexRemote and EQMOD. NexRemote was there first and started out as an interesting project by a couple of talented amateur astronomer - programmers, Andre Paquette and Ray St.Dennis, to see if they could develop a piece of software that could take the place of the Celestron NexStar hand controller. The rest is history: Celestron took an immediate interest in their program, hcAnywhere, and made it and its creators part of the Celestron family (changing the app’s name to the less funky NexRemote in the process). What’s the benefit of NexRemote? If your Celestron is old enough to benefit from a more modern HC (but young enough to be able to use NR), NexRemote will give you all the benefits of the current Celestron programmable hand controller. In fact, NexRemote is the current Celestron hand controller, just running on a laptop instead of a hand paddle. No difference whatsoever.

In addition to being cheaper than a replacement Celestron HC, NexRemote has the benefit of being easily used on a variety of scopes. You can, for example, use it on a CG5 mount one night and a CPC the next without having to “flash” new firmware as you would with a “real” programmable HC. Perpaps the coolest thing? You may be wondering how you slew the scope around the sky with a laptop. Does it have to be at the observing position? Do you have to run back and forth? No. NexRemote allows the use of a wireless PC “gamepad” like the Logitech Wingman as the physical HC. Not only can you slew the scope with the joystick, the gamepad’s buttons can be mapped to perform most telescope functions. Only drawback? As mentioned above, NexRemote does not like all USB – Serial converter cables. The Keyspan USB-serial cable or a PCMCIA serial card will make RS-232-less laptops work fine with NR, however.

EQMOD is much like NexRemote, except it works on those “other” Synta telescopes (Synta owns Celestron), the EQ5/Skyview Pro, HEQ5/Sirius, and EQ6/Atlas. Why not just use NexRemote with these mounts? It will not work on the non-Celestron Syntas due to their different motors and different firmware. That being the case, a team of independent software gurus led by Mon Sarmiento set out to do a similar program for the Atlas and its kin. The result is similar in many ways to NR. It allows the hardware hand control to be left in the astro-stuff case—or at home—and allows a gamepad to be used for scope control (in my opinion, a wireless joystick from Walmart is way better than any telescope hand control). Like NexRemote, EQMOD is currently a “Windows-only” application, I’m afraid. Unlike NR, EQMOD is freeware.

In addition to letting you dispose of the non-virtual HC, EQMOD adds features and usability. While the SynScan hand controllers used on the Atlas and the other Syntas look a lot like the NexStar hand controllers, even the latest versions are missing some desirable features like, yeah, you guessed it, sync (though recent SynScans do feature a similar utility). EQMOD adds the sync feature and much more, and, in the opinion of many users, also improves the mounts’ go-to and guiding accuracy. One thing I like about EQMOD is that it permits the use of almost any joystick imaginable—even an Xbox model will work--NexRemote is pretty much confined to the Logitech ones.

Despite their conceptual similarity there is one major difference between EQMOD and NexRemote—EQMOD is really an ASCOM driver rather than a standalone program; you have to run it with another astroware. But that’s alright. The requirement that it must be used with a planetarium (or a Planner’s sky display) allows it to offer a strikingly simple and effective method for go-to alignment. You align the scope by clicking on stars on the planetarium’s display and having the scope go-to them. Center ‘em, push a button on the gamepad, and you are ready for a night of deep sky voyaging. NexRemote is a masterful piece of programming, but EQMOD is truly astounding.

You ain’t impressed, huh? I hear you, Boudreaux. The problem with laptop computers is not everybody wants to carry one into the field. Most of us are toting a ton of gear as is, and the thought of adding one more major puzzle piece along with its support stuff (like a big battery; forget running off the PC’s internal battery—for long, anyway) does not appeal. Not only that; laptops are much cheaper than they used to be (500 bucks will get a more than astronomy suitable new one), but they still don’t put ‘em in the Crackerjack box, and some amateurs quail about using one on a cold and dew-soaked observing field. Me? I think laptop PCs are the best thing to hit amateur astronomy since Dobs and SCTs, but I do understand this mindset. What to do? PDA it.

By “PDA,” I mean, for those even more technically backward than Unk, a Personal Digital Assistant. You know, a Palm Pilot—that’s what they used to call ‘em anyhow. PDAs are currently available in two major flavors. Palm is still hanging on, but there’s also, yep, Microsoft’s competing device, the Pocket PC (PPC), which runs the Windows Mobile operating system. Pocket PCs are sold by a variety of manufacturers, while Palms are currently sold only by Palm. There is a wealth of astronomy software available for both flavors, software that will frankly amaze. Modern PDA planetariums can do almost anything their PC based big sisters can; sometimes even more.

Which, though, Palm or PPC? I used to say, “Pick the software you want, and buy the device it runs on.” That’s still good advice. Some of the best loved PDA astro-softs are still platform “exclusive.” Bisque’s TheSky Pocket Edition only runs on PPCs, and the single major planner for these devices, Pocket Deepsky, is PPC-only as well. The granddaddy of ‘em all, Planetarium for Palm, is, natch, just for Palms. The trend, though, is for cross-platform PDA software. The current king-of-the-hill (so I’m told) is Astromist, which is available for both types of hand-helds.

All software things being equal, though, Palm or PPC, and which specific model (there are many)? I’d suggest two hardware criteria: display and memory. A high resolution screen as large as you can get is a must if your eyes are as bad as my old peepers and even a laptop screen looks like a parade of crawling bugs without your glasses. Memory is also important if you want plenty of objects and pictures. That’s not as much of a show-stopper as it used to be. PDAs now have substantial onboard memory and the SD memory cards they use are dirt cheap.

One further consideration? After a period when the Pocket PC was generating all the interest and all the publicity, the Palm seems to be back in the lead, and I have begun to wonder how long the PPCs will be around. Why is that? The Palm operating system is simpler and easier to use, day or night, than the PPC's Windows Mobile OS. Also, Palm has insinuated itself into the cell phone biz in a bigger way than PPCs. Many advanced cells are Palms as well. That’s right, while you’re waiting for the scope to slew to M15 you can call Aunt Lulu and ask what she’s fixing for Sunday dinner.

How are PDAs at the scope? They can be fantastic and probably come closer than anything else to providing you with a “replacement” go-to hand control. With one of these slick weasels running the telescope, you will never, ever wish you had a Starbook for your LX200—you will have that and more. The features PDA authors are packing into their programs are amazing. Astromist, for example, will let you slew the telescope around with the Palm’s buttons. Unlike the Starbook, you can use your PDA and astro-soft on almost any go-to scope in your inventory, and any that you will acquire in the future. I swear, it’s sweet: align the scope with the old HC, Velcro it to the side of the tripod, and spend the rest night operating the old war horse via a hand held with a high resolution color display. If you’d like to learn more about PDAs and astronomy might I be so bold as to suggest you sign up for Unk’s long running Palmastro Yahoogroup (which despite the name covers PPCs too)?

Any monkey wrenches to jam up the works? Only one, really. You’ll naturally have to interface PDA to scope. That used to be easy way back when Palms featured serial ports. That’s gone the way of the buggy whip with the coming of USB. Now, all PDAs are hooked to a PC (to load programs and “sync” data) via USB and it ain’t easy to get ‘em to talk RS-232. You can get serial cables for contemporary PDAs, but plan to pay about 50 – 75 bucks for one. Dangit.

So the ideal way to “upgrade” a decrepit go-to is with a PDA? Right now, prob’ly. These small wonders will, depending on the software you choose, be able to add most of the missing features you pine for on your Ultima 2000. As usual, though, I ain’t quite satisfied. PDAs work and work well at the scope, BUT they are generic computing devices not specifically designed for use with a telescope. What if somebody came out with a PDA/HC device designed to be used exclusively with telescopes (see my Photoshop made mockup above)?

What do I have in mind? Something in the size range of PDA – HC – TV remote. It would have a nice high resolution screen. It would also have plenty of well-laid out telescope - centric buttons, including nice, big north-south/east-west ones to mash. What would also make it better is that its software would be in ROM. No memory cards or program loading to deal with. Since “Rod’s HC” would be designed for astronomers, the night vision mode would be perfect—no consarned white border around the screen—and could be dimmed to extinction. The interface would be RS-232 to the scope’s normal serial port. Users would initially align their scopes with the old HC, just like normal (though I’m open to ones that would replace the HC completely, technical and legal considerations probably preclude that) but Rod’s HC would take over afterwards.

Hardware and software details? I ain’t smart enough to work out things like “Which operating system?” “What kinda processor?” “ASCOM or built in drivers?” “How much memory?” “What kinda power source?” yadda, yadda, yadda. I’m sure the Bright Boys can puzzle it all out. It would take some money and talent to produce something like this, but it seems to me this would be very popular in a small amateur astronomy sorta way. There are plenty of old go-tos out there that still, believe it or not, work exceptionally well, and wouldn’t get sent to off to the Astromart if the owner could find a way to add a little more glitz and a few more features. This is especially true as we hit leaner economic times and some of us begin to be of the opinion that them old go-tos were actually better built mechanically and electronically—if not optically—than the modern marvels. Convinced? OK, one of y’all kick in a few million and we’ll setup a company and start crankin’ out Rod’s HC!


For me one big advantage of ASCOM is that it allows multiple programs to connect to the mount at the same time. So I can have my planetarium, and Maxim (say) both communicating without having to keep disconnecting one to connect the other.

PDAs? The only way to connect now is Bluetooth. Wireless freedom, stick the PDA in you pocket when you aren't using it. Sure you need a serial/Bluetooth adapter to plug into the mount (unless you have a Paramount with it built-in), but when it works it is amazing.

Howdy Unk!

Hows about a post or two on using this pc-go-to thingy?
I'm thinking you need to teach us a bit about periodic-error-correction and the basics of autoguiding!

keep up the good work!
Since you axed for it...a blog entry on the autoguiding game will be put on the ol' schdule!
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