Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Building 10Micron mount models

  • This topic is locked This topic is locked
723 replies to this topic

#126 Tonk

Tonk

    Cosmos

  • *****
  • topic starter
  • Posts: 9,434
  • Joined: 19 Aug 2004
  • Loc: Leeds, UK, 54N

Posted 28 January 2019 - 10:56 AM

Also I am curious if people are making both east and west pierside models.


This is automated in the internal 10Micron model builder. If there are 11 terms its  a single all sky model. If 22 then separate east and west
 

#127 555aaa

555aaa

    Vendor (Xerxes Scientific)

  • *****
  • Vendors
  • Posts: 2,023
  • Joined: 09 Aug 2016
  • Loc: Lynnwood, WA, USA

Posted 28 January 2019 - 03:03 PM

Thanks Tony. The following link describes the 15 terms that are used in the Alcor system Nova mounts and they are the same terms from Tpoint used by SB. The term named TF is tube flexure; FO, DAF, and DAB are all flexure error terms. I was wondering if 10Micron uses the same coefficients or are they using something proprietary? In the other two packages you can just read the model terms and see where you have large errors coming in. It seems intuitive to me that they would delete the four encoder first order error terms which gets you the 11 "standard" terms (which still is plenty!) Knowing those might help someone diagnose where problems are coming in when using model-based tracking.

 

http://www.alcor-sys...nting_model.pdf

 

-Bruce.


 

#128 PeterWar

PeterWar

    Messenger

  • -----
  • Posts: 472
  • Joined: 25 Aug 2011
  • Loc: Roses, Girona (Spain)

Posted 28 January 2019 - 03:32 PM

However you should also note that guiding on a 10Micron mount shouldn't have to work too hard making corrections unless your mirror really flops about

Indeed, I've set aggresiveness at Maxim DL at 2.0 and autoguide speed at 0.33x in the 10 Micron driver. It works, but sometimes I have to recalibrate the guiding star, I don't know why. At this point I attribute it to my -08' 36" orthogonality error. Next month I'll remove the OTA to do some cable maintenance and will attempt to reduce it.


 

#129 Tonk

Tonk

    Cosmos

  • *****
  • topic starter
  • Posts: 9,434
  • Joined: 19 Aug 2004
  • Loc: Leeds, UK, 54N

Posted 28 January 2019 - 04:09 PM

At this point I attribute it to my -08' 36" orthogonality error.


I'm certain that this wont be a factor - and the 10Micron manual suggests this too

 

My orthogonality error is ~37' and I've not seen any problems


Edited by Tonk, 28 January 2019 - 04:11 PM.

 

#130 akulapanam

akulapanam

    Mercury-Atlas

  • *****
  • Posts: 2,795
  • Joined: 26 Aug 2012

Posted 28 January 2019 - 11:34 PM

Indeed, I've set aggresiveness at Maxim DL at 2.0 and autoguide speed at 0.33x in the 10 Micron driver. It works, but sometimes I have to recalibrate the guiding star, I don't know why. At this point I attribute it to my -08' 36" orthogonality error. Next month I'll remove the OTA to do some cable maintenance and will attempt to reduce it.


Are you making sure your calibrating where the 0 dec intercepts with the meridian?
 

#131 PeterWar

PeterWar

    Messenger

  • -----
  • Posts: 472
  • Joined: 25 Aug 2011
  • Loc: Roses, Girona (Spain)

Posted 02 February 2019 - 07:03 AM

Actually I wasn’t, what is the reason to choose this intersection?

Thanks in advance
 

#132 Whichwayisnorth

Whichwayisnorth

    Gemini

  • *****
  • Posts: 3,331
  • Joined: 04 Jul 2011
  • Loc: Southern California

Posted 18 February 2019 - 11:36 AM

Calibrating guiding at DEC 0, or as close as you can get to there and close to the meridian, usually on the east side by about an hour, lets the calibration get the best data on the behavior of the mount and how it responds to guide corrections.  Just a general rule of thumb.  Think of it as eliminating one thing that could cause bad guide calibration if you follow that rule. 

 

Perhaps PHD2 is smart enough now that it doesn't need to do that as longs as it can get the DEC from the ascom driver but some areas of the sky I think may not provide enough data to get it as accurate as you would want.

 

I rarely guide anymore. With the 10micron I just make a 50 point model and I'm done.


 

#133 Fukinagashi

Fukinagashi

    Mariner 2

  • -----
  • Posts: 228
  • Joined: 10 Sep 2014
  • Loc: Italy

Posted 25 February 2019 - 11:15 AM

Anyone could tell me if it's possible and how to add refinement points to an existing model with Mount Wizzard 3 without starting by scratch?


 

#134 fjhdavid

fjhdavid

    Lift Off

  • -----
  • Posts: 8
  • Joined: 13 Feb 2020

Posted 17 March 2020 - 10:25 AM

Hi,

 

I have a newcomer question for the 10micron mount:

 

assuming, you edit and save a model mount for your telescope (with tube, camera...)

 

 

if you move this telescope (mount+tube+CCD+...) just several feets away (same GPS position) , do you have:

 

- to generate a new model mount?

- can you use the same model than before directly?

- do you have to execute a preliminary 3 stars manual pointing + polar alignement + an another 3 stars manual pointing, before using the same model?

 

best regards

François


Edited by fjhdavid, 17 March 2020 - 10:34 AM.

 

#135 Lead_Weight

Lead_Weight

    Vanguard

  • *****
  • Posts: 2,049
  • Joined: 21 Jul 2016
  • Loc: Houston

Posted 17 March 2020 - 12:37 PM

Hi,

 

I have a newcomer question for the 10micron mount:

 

assuming, you edit and save a model mount for your telescope (with tube, camera...)

 

 

if you move this telescope (mount+tube+CCD+...) just several feets away (same GPS position) , do you have:

 

- to generate a new model mount?

- can you use the same model than before directly?

- do you have to execute a preliminary 3 stars manual pointing + polar alignement + an another 3 stars manual pointing, before using the same model?

 

best regards

François

Yes, you would need to build a new model. The chance of you setting it up precisely in the exact same direction and leveling would be slim to none, and the accuracy would require you create a new model. 3 star, plus polar alignment, and then a new model.


 

#136 Michaeljhogan

Michaeljhogan

    Messenger

  • -----
  • Posts: 485
  • Joined: 25 Aug 2014

Posted 17 March 2020 - 04:00 PM

just waiting for mine to be delivered


 

#137 lambermo

lambermo

    Apollo

  • -----
  • Posts: 1,108
  • Joined: 16 Jul 2007
  • Loc: .nl

Posted 18 March 2020 - 08:16 AM

if you move this telescope (mount+tube+CCD+...) just several feets away (same GPS position) , do you have:
- to generate a new model mount?


Ideally yes because alignment will be off.
 

- can you use the same model than before directly?


You can, but I would not recommend it. GOTO's will no longer be accurate. And tracking will be less than optimal (but still very good).
 

- do you have to execute a preliminary 3 stars manual pointing + polar alignement + an another 3 stars manual pointing, before using the same model?


You can adjust (== offsetting the axis angles) the entire model with a plate-solve of just 1 star. From the API manual :

:CM#
Synchronizes the position of the mount with the coordinates of the currently selected
target.
Starting with version 2.8.15, this command has two possible behaviours depending on
the value passed to the last :CMCFGn# command. By default after startup, or after
the :CMCFG0# command has been given, the synchronization works by offsetting the
axis angles. If the :CMCFG1# command has been given, it works like the :CMS#
command, but returning the strings below.
Returns:
the string “Coordinates matched #” if the coordinates have been synchronized
the string “Match fail: dist. too large#” if the coordinates have not been synchronized

Having said all that, why not just build a new model ? Takes about 10 minutes when fully automated. See my sig for what I use for that.

-- Hans


 

#138 fjhdavid

fjhdavid

    Lift Off

  • -----
  • Posts: 8
  • Joined: 13 Feb 2020

Posted 18 March 2020 - 10:30 AM

thanks for your answers!!!

 

I knew I can save a model with model creator (for example) and always stay with it.

 

But, if I understand, what I will need before, in order to use it again, is to perform a 3 stars pointing, a polar alignement and a 3 stars pointing and after only, use the model.

 

Am I right?


Edited by fjhdavid, 18 March 2020 - 12:22 PM.

 

#139 Tonk

Tonk

    Cosmos

  • *****
  • topic starter
  • Posts: 9,434
  • Joined: 19 Aug 2004
  • Loc: Leeds, UK, 54N

Posted 23 March 2020 - 07:34 AM

No - if you are setting up the mount fresh each night you will need to rebuild from scratch. Typically the model will be generating 22 terms (11 for each hemisphere). These terms incorporate a lot of stuff about the behaviour of the scope with respect to the mount as well as the mount in relation to the stars. You are not going to reproduce this using an old model.

Permanent setups can reuse models night after night - mine current one is now in its 13th month and still tracking accurately to the 15 minute mark. However before switching to a permanent observatory set up I built a fresh model for every imaging session I did with my mobile rig. I did that for 6 years.


 

#140 Tonk

Tonk

    Cosmos

  • *****
  • topic starter
  • Posts: 9,434
  • Joined: 19 Aug 2004
  • Loc: Leeds, UK, 54N

Posted 23 March 2020 - 07:40 AM

I forgot to say - even manually with an astrometric eyepiece for centering - you can get aligned and the model built in the twilight phase - easy! Thats 3 iterations of 25 star models with 2 alignment refinements and this works well under the constraints of mobile (i.e. setting up each time) imaging. If that is not clear - build 25 star model, polar align, build 25 star model, polar align refine, build 25 star model - stop. If your scope is rigid and no flexure/flop - then expect polar alignment to be below 30"

 


 

#141 Tonk

Tonk

    Cosmos

  • *****
  • topic starter
  • Posts: 9,434
  • Joined: 19 Aug 2004
  • Loc: Leeds, UK, 54N

Posted 25 March 2020 - 10:49 AM

Just a note about lee ways - >25 point model is ideal but you can still do well dropping that to 12 stars - but evenly spread around the sky. However going below 12 star models is not recommended (by me).

 

If you are not convinced and have a night to waste - try repeatedly building pointing models to a specific number of stars. Do each model size three times and note down the PA error for each one and how reproducible (clustered) these values are. I've done this - below 15 or so stars the reproducibility is not good - above 15 it rapidly starts to tighten up as does the pointing RMS. Plotting this is useful  to understand what gains you get by progressively adding more stars to the model size.


 

#142 EFT

EFT

    Vendor - Deep Space Products

  • *****
  • Vendors
  • Posts: 6,234
  • Joined: 07 May 2007
  • Loc: Phoenix, AZ

Posted 25 March 2020 - 12:16 PM

Tonk,

 

In your alignment method, what do you consider to be an RMS level that will be sufficient for what you want to do?


 

#143 hnau

hnau

    Vostok 1

  • *****
  • Posts: 194
  • Joined: 12 Sep 2007
  • Loc: AZ

Posted 25 March 2020 - 06:20 PM

I don't do much beyond 35 points in a model, only because I haven't found a need to do more (at least with any refractors I've owned).  The below for me is sufficient to run unguided up to 20 min anywhere in the sky, however I'm usually running 5min subs at most due to standardizing on sub lengths for unity gain with my camera.

 

Results from my last model creation run w/ the Esprit 120; built in just over 15 min and no points removed:

35 point model
RMS error = 1.76
Elapsed time: 16:33

 

#144 Tonk

Tonk

    Cosmos

  • *****
  • topic starter
  • Posts: 9,434
  • Joined: 19 Aug 2004
  • Loc: Leeds, UK, 54N

Posted 26 March 2020 - 04:15 AM

In your alignment method, what do you consider to be an RMS level that will be sufficient for what you want to do?


Well RMS is telling you only about the accuracy regarding pointing and hence finding your target. The RMS value you get has more to do with the rigidity of your OTA and camera than anything else once you get your model size optimal. Regarding RMS values - I typically get better than 10" with my scopes and am happy with that. Around 2-3" is typical with my TOA130.

My comments above were really about getting a good PA and knowing that the stated PA error was a reasonably accurate one too - its not the case in very small models.
 


Edited by Tonk, 26 March 2020 - 04:19 AM.

 

#145 Tom Polakis

Tom Polakis

    Vanguard

  • *****
  • Posts: 2,198
  • Joined: 20 Dec 2004
  • Loc: Tempe, Arizona

Posted 28 March 2020 - 02:07 PM

Well RMS is telling you only about the accuracy regarding pointing and hence finding your target. The RMS value you get has more to do with the rigidity of your OTA and camera than anything else once you get your model size optimal. Regarding RMS values - I typically get better than 10" with my scopes and am happy with that. Around 2-3" is typical with my TOA130.

My comments above were really about getting a good PA and knowing that the stated PA error was a reasonably accurate one too - its not the case in very small models.
 

I have a 2000 mount set up permanently, and only occasionally re-do the model using Per's ModelMaker.  Am I reading from your earlier comments that 10Micron has their own model-building software?  If so, is it accessed from their Forums area?  Thanks.

 

Tom


 

#146 Tonk

Tonk

    Cosmos

  • *****
  • topic starter
  • Posts: 9,434
  • Joined: 19 Aug 2004
  • Loc: Leeds, UK, 54N

Posted 28 March 2020 - 06:12 PM

Am I reading from your earlier comments that 10Micron has their own model-building software?


No they (10 Micron) don't - however three 10Micron customers have built their own. Two are still very active - and yes if you go to the software topic in the forum you should be able to find the latest and greatest of these offerings. I'm using MountWizzard - its has nice model analysis tools
 

 

This is automated in the internal 10Micron model builder.


Or where you referring to this? Here I'm referring to the firmware component that processes all the points you input into the actual pointing model used by the mount - this can be via a software app or via the hand pad with manual alignment on reference stars. Note that ModelCreator, MountWizzard, ModelBuilder etc. are not actually model builders - these are automated point selection and input apps that feed the raw data to the mount computer - which then does the the real model building.


Edited by Tonk, 29 March 2020 - 04:04 PM.

 

#147 EFT

EFT

    Vendor - Deep Space Products

  • *****
  • Vendors
  • Posts: 6,234
  • Joined: 07 May 2007
  • Loc: Phoenix, AZ

Posted 28 March 2020 - 07:01 PM

The other app is ModelCreator which you can find at The author is very good about addressing any problems.  He is also the one making the weather stations for the 10Micron mounts.  


 

#148 Michaeljhogan

Michaeljhogan

    Messenger

  • -----
  • Posts: 485
  • Joined: 25 Aug 2014

Posted 28 March 2020 - 10:40 PM

The other app is ModelCreator which you can find at The author is very good about addressing any problems.  He is also the one making the weather stations for the 10Micron mounts.  

Ed my mount should be here on Monday delayed how important is this how big a difference ?

 

I forgot to order this from Dutch EU 10 Micron dealer Robtics UK left EU so their prices are hundreds more well they made their bed

Attached Thumbnails

  • Screenshot_2020-03-29 Astromi ch MGBox V2 Meteostation USB Weather Station with GPS First Light Optics.png

Edited by Michaeljhogan, 28 March 2020 - 10:55 PM.

 

#149 EFT

EFT

    Vendor - Deep Space Products

  • *****
  • Vendors
  • Posts: 6,234
  • Joined: 07 May 2007
  • Loc: Phoenix, AZ

Posted 29 March 2020 - 02:47 PM

It depends in part on where you are shooting in the sky.  But the ability to constantly adjust the diffraction parameters the model is constantly being corrected for that can be caused by diffraction.  The additional GPS capability is handy if you are not permanently mounted.  It's one of those things that you use to try to squeeze out every bit of tracking precision you can get.  Absolutely necessary?  Maybe not.  Worth the addition?  Probably.


 

#150 David_Ritter

David_Ritter

    Viking 1

  • *****
  • Posts: 624
  • Joined: 31 Jan 2014
  • Loc: Edmonton, Alberta, Canada

Posted 29 March 2020 - 07:26 PM

I agree that a GPS is not absolutely necessary. But it sure is nice to have, particularly for a mobile setup when travelling.


 


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics