Freeware for plate solving

[NickH]

Thought this may come in handy for those of you on a budget, which doesn't stretch to CCD autopilot/pin point etc..

StarLocatorElbrus : Star Locator Elbrus

Credit crunch astronomy :-)

[NickH]

Ideally though, I'd like to see something like DAWN support full integration from the image acquisition, to then plate solve, and adjust based on target... so...if you do a GOTO, and it's slightly out, it plate solves, and then slews the mount so that your target is EXACTLY dead centre of your CCD FOV.. integrated into EQMOD....oh nice!

[themos]

Have you compared it to GPL'ed astrometry.net (http://astrometry.net/use.html)?

[NickH]

requires a cygwin compile and run...whilst I like Linux...I don't want all that munge on the little netbooks running all the other apps

The online version seems useful, but doesn't solve the integration problem w.r.t re-positioning the scope..

It's not that hard...take an app like DAWN integrate the art capture side, capture the image, (which it will know the pixel size etc, all you have to do is select from a simple list of aperture and focal length the scope in use). that gives you the scale. Then that FITS image is cross matched to the GSC catalogue and the software then sends a command (based on what it thinks your supposed to be pointing at...taken via ASCOM/CDC/EQMOD) to move the scope so that the object is dead centre

[blinky]

Nick - maybe you should make Chris (Of EQMod fame) aware of this thread and see if he can maybe start to look at integrating this into EQMod? I have to agree it would be great to have plate solving and then repositioning integrated into EQMod... we can but dream!

[SteveL]

EQMOD is *just* a mount driver, and should not be in any way made to integrate into various applications to grab images and plate solve. That is not EQMODs job.

[themos]

If you can use the online version, it should be a simple matter to parse the coordinates off the results web-page and turn them into an EQTour list item. You then use EQTour to do an EQMOD Sync at the current position and then slew to the center of the object (if you know its coords reliably).

[NickH]

Steve, not suggesting that EQMOD do that, more the other way around, that the capture application does the plate solve, and then feeds the offset/slew to EQMOD via POTH or similar to move the scope to the correct target position.

Online version means websites etc...useless in the field so to speak. GSC database and plate solving via a capture app is the answer..

W.r.t Chris, I will... (he's on another thread relating to the EQDIR)

[brianb]

requires a cygwin compile and run...whilst I like Linux...I don't want all that munge on the little netbooks running all the other apps

"All that munge" is about 1/10 the size of e.g. Microsoft Office. And you can throw away everything except cygwin.dll and the executable after compiling.

[NickH]

And who uses office?

...not I...

I have the leanest pair of netbooks on the planet..

Hmm...if the compile etc works that well, I may give it a blast...

[SteveL]

Steve, not suggesting that EQMOD do that, more the other way around, that the capture application does the plate solve, and then feeds the offset/slew to EQMOD via POTH or similar to move the scope to the correct target position.

Cool, so we ned to get CCD Inspector or CCDAP to use this freeware plate solving application, and then let it move the mount. I know that using CCDI + MaximDL/PinPointLE for slew then plate solve then reslew is just about the best thing I have seen at work in a long time

[NickH]

Indeed. Playing with pinpoint demo and LE versions, is what kind of got me thinking.. and seeing the online (flickr) astrometry.net tool, it appears that with so much data available, and such good free/low cost software, it makes sense to try to integrate it all.

Would make for a more accurate mosaic tool too...not as much need for overlapping regions if you can accurately plate solve

[themos]

It occurs to me that plate solving could help with polar alignment, too. Take two pictures of star-fields separated by pure mount-RA displacement and you can determine your azimuth error.

[brianb]

.if the compile etc works that well, I may give it a blast...

You can compile on a different system, then just copy cygwin.dll and the executable to a directory on the exectutable search path on the laptop. Two files, might take all of two megabytes.

[NickH]

:-)

In progress.. on the work machine..

Thanks Brian... you whetted my appetite

[arad85]

It occurs to me that plate solving could help with polar alignment, too. Take two pictures of star-fields separated by pure mount-RA displacement and you can determine your azimuth error.

Isn't that what PoleAlignMax does (via MaximDL/Pinpoint LE)?

[MartinB]

I know that using CCDI + MaximDL/PinPointLE for slew then plate solve then reslew is just about the best thing I have seen at work in a long time

Ooh, tell me more Steve. What is the role of CCDI in that arrangement?

Any free plate solving software is going to be useful for people without deep enough pockets for Maxim and it's ilk. Even if it doesn't integrate. Having spent frustrating times at 2000+ f/l trying to get a target on an SXV H9 chip it sounds like a god send.

[arad85]

requires a cygwin compile and run...whilst I like Linux...I don't want all that munge on the little netbooks running all the other apps

Huh Cygwin only occupies disk space if you aren't running any cygwin app. My cygwin install takes 787Mbytes on my home machine and it's a fairly full install... Of course, if you have a small disk, it may be an issue but you actually have a command tool that is useful with cygwin

[NickH]

I have netbooks with about 300MB left on them...not a "huh" at all.. in the obsy (SSD's ), the images get punted via SDHC card (deep sky) up to my Mesh folder... the rest of the SSD space is taken with CDC, PHD, EQMOD, Windows :-), Art capture et al.

But, Brian's info has me compiling it and will give it a blast. I like neat solutions though...and this is not really a neat solution.

[themos]

Isn't that what PoleAlignMax does (via MaximDL/Pinpoint LE)?

I've just had a read of some website that suggests it does.

[SteveL]

Isn't that what PoleAlignMax does (via MaximDL/Pinpoint LE)?

Thats EXACTLY what PoleAlignMax (PAM) does. You move the scope to a medium brightness star and start the PAM run... it takes takes an image, plate solves, slews in RA a set number of degrees (user configutable) east or west (again, user configurable), then does it again, and again. From that it has three points that are in e straight line in RA, and it also has the plate solved RA/Dec co-ords, and from that it can work out how far out you are.

It the slews back to your initial point, ask you to center the star in teh cross hairs (looping through short exposures while you move the star with the hand controller or EQMOD rumble pad), then it moves the mount and ask you to recenter the star using the MOUNT'S Azimuth adjusters only. Then it ask you to center the star again with the HC/EQMOD Pad, then ask you to recenter the star using the MOUNT'S Altitude adjusters only. That should get you pretty close, and it takes 5-10 minutes once you know the routine. A second run will get you even closer. For my widefield images, a single run is more than enough to get pixel perfect 15 minute subs without any field rotation.

[arad85]

in the obsy (SSD's )

So you are short of disk space then

[themos]

Any free plate solving software is going to be useful for people without deep enough pockets for Maxim and it's ilk. Even if it doesn't integrate.

If it's free-as-in-speech, as opposed to free-as-in-beer, it can also never be taken away and can be integrated as soon as someone has a bad enough itch to scratch.

[SteveL]

Ooh, tell me more Steve. What is the role of CCDI in that arrangement?

CCD Commander slews tells the mount to slew to target, it tells CCDSoft or Maxim to take an image, it plate solves that image for RA/DEC of the image center, then tells the mount to either:

slew to where it thinks it is plus difference between where it think its is and the real RA/DEC (i.e an offset from wher it currently is)

or

sync the mount where it really is, then reslew based on a new alignment pattern from that sync. In EQMOD, I use this option so the slew+sync adds to the alignment map.

[NickH]

Hmm... definitely working, but not elegant or cheap..

Thanks for your input Steve, it's very interesting and valuable.

So the way I see it...

Maxim DL ($$$$$$), + CCDI (£££) + EQMOD (free) + Pinpoint ($$$$ maybe not needed?) + ASCOM (Free) + CDC (or planetarium app of choice) = much spondoolees

or

Nebulosity ($49) + EQMOD (pulse guide) + ASCOM (free) + CDC (free) + Platesolver 1.0 :-) (hopefully free when it's done!) = $49

and if Nebulosity could integrate PHD routines into its core, even more elegant and simple..