How do I _TELL_ eqascom where it's pointed?

[pete_l]

After a very brief power cut just as I was about to start imaging, Cartes du Ciel and EQASCOM now both think that the telescope is pointing at some random point in Cephus. In fact it is pointing at a nice little galaxy cluster in Pegasus.

Now I *could* get up, go outside, reset EVERYTHING and start all over again. However I feel that I should just be able to press some buttons on the keyboard and tell EQASCOM where it is pointed. I don't want it to moan that the co-ordinates are more than 15° away. I don't want anything except instant, unquestioning obedience. And I don't care if it messes up my pointing model or anything else for that matter. That's not too much to ask from a computer program, is it?

The question is, what buttons do I press to make this happen? Answers would be greatly appreciated.

[steppenwolf]

If it were me, I'd take a photograph of where the telescope is currently pointing, plate solve the image and sync the mount to those coordinates in Cartes du Ciel - all without leaving my cosy command room.

[alan4908]

8 hours ago, pete_l said:

After a very brief power cut just as I was about to start imaging, Cartes du Ciel and EQASCOM now both think that the telescope is pointing at some random point in Cephus. In fact it is pointing at a nice little galaxy cluster in Pegasus.

Now I *could* get up, go outside, reset EVERYTHING and start all over again. However I feel that I should just be able to press some buttons on the keyboard and tell EQASCOM where it is pointed. I don't want it to moan that the co-ordinates are more than 15° away. I don't want anything except instant, unquestioning obedience. And I don't care if it messes up my pointing model or anything else for that matter. That's not too much to ask from a computer program, is it?

The question is, what buttons do I press to make this happen? Answers would be greatly appreciated.

Occasionally, I've also had this also happen to my NEQ6 when a power cut has occurred. Generally speaking, I found that the loss of sync resulted in an error of much more than 15 degrees and also impacted the park positions. Since my telescope can hit the roll off roof, I decided that going outside and performing a complete reset was the safest option.

As I also operate my telescope remotely, once I also tried to the plate solving resych technique remotely, which fixed the position of the scope but not the park positions.  As a consequence, at the end of the night, when my automated software issued a command to safely park the scope, my telescope slewed to an incorrect park position with the telescope protruding above the roof line !  At this point, the roof would normally close but this was prevented by some safety sensors that only allow the roof to open or close when the telescope is in the "safe" position.  Fortunately, it didn't rain that evening, so everything was OK.  After this event, I decided to install an internal rain alarm that goes off if water is getting into the obsey. 

As far as I can tell, for the NEQ6, the only reliable solution to this issue is to install a UPS. 

Alan 

[michael8554]

14 hours ago, alan4908 said:

once I also tried to the plate solving resych technique remotely, which fixed the position of the scope but not the park positions.

That's puzzling me - once you've told the scope where it's now pointing, why wouldn't it know where the park position is?

My LX200GPS occasionally loses it's way, I move it to a known star and synch, and then I'm good to go again, and it goes to the correct park position at bedtime.

Michael

[alan4908]

7 hours ago, michael8554 said:

That's puzzling me - once you've told the scope where it's now pointing, why wouldn't it know where the park position is?

My LX200GPS occasionally loses it's way, I move it to a known star and synch, and then I'm good to go again, and it goes to the correct park position at bedtime.

Michael

Hi Michael

Yes, I agree it is puzzling.

My theory is that the power cut must have somehow corrupted the files that are used to store the custom park positions. In the particular case referenced, my "reset" included storing new park positions. 

Alan 

 

[daz]

This is from memory - and therefore may be flawed....

• Clear your alignment points (having saved if required)
• Plate solve
• Park to current position
• Unpark
• Re-synch the encoders

ASCOM should now know where you are pointing, and where the encoders are so your park positions should now function again, and you can reload your saved model.

 

As an aside, I have set up a FLAT park position where both axis are horizontal and level. If I have an issue, I park to this position and manually adjust the axis until the perfectly level - however, I've not found a way to do this from the comfort of my armchair yet!!

 

[Robd]

My understanding is as follows-

1) Your mount does not have dual encoders, therefore when re-starting Eqmod has no way of determining where the scope is pointing. 

2) I suspect that EQ will update files to indicate parked or not. It may continually update with current RA/DEC, but I would have thought that this was unlikely - unnecessary overhead replacing a file every second.

3) EQ depends on starting in a known position,  hence Park before power off.

4) A power cut is very unlikely to corrupt a file unless a write was in progress in which case EQ  possibly is frequently updating or you were very unlucky. 

I agree with Steppenwolf,  however I think that you will first have to clear your pointing model since existing 'corrections' will be drastically different to the new position and  now wrong.

Actually that raises a possible downside to this solution. 

Usually we initially start at the default position of pointing north. Corrections are then fairly small, let's say 1degree. If after the power cut, restart and sync the error is now 90 degrees,  I suspect that this might make ' mapping ' less reliable. I am not totally convinced that mathematically I am correct but gut feeling says that the smaller the correction the better.

Either way unfortunately there is no magic button to put everything right again.

 

Rob

[pete_l]

19 minutes ago, daz said:

This is from memory - and therefore may be flawed....

• Clear your alignment points (having saved if required)
• Plate solve
• Park to current position
• Unpark
• Re-synch the encoders

ASCOM should now know where you are pointing, and where the encoders are so your park positions should now function again, and you can reload your saved model.

 

As an aside, I have set up a FLAT park position where both axis are horizontal and level. If I have an issue, I park to this position and manually adjust the axis until the perfectly level - however, I've not found a way to do this from the comfort of my armchair yet!!

 

Yes. It does seem that it is impossible to do something as simple as manually entering an RA / Dec position into EQAscom.

As for the plate solving route, I tried many different types and none were satisfactory.

Astrotortilla simply failed to connect to my QHY5Lii guide camera

 

Platesolve accepted an image but couldn't solve it.

Pointcraft (part of Astrophotography tool) was unable to do anything at all

 

Though Astrometry.net, as always, produced a perfect "solve". The only trouble being that I had to then enter the centre RA / Dec co-ordintates by hand. Which brings me back to the original point ....

 

The next night (last night), after I gave up in disgust the previous night, I turned everything off and on again. Like you I have my "park" position set with the scope and axis flat horizontal and pointing north. But when I brought up Cartes du Ciel and started ASCOM/EQAscom it insisted that my mount was at the default position, weights down and the OTA pointing at Polaris. It wasn't and there appeared to be no way to persuade the software that it was wrong. Had I attempted tp park the rig at that time, the OTA would have crashed into the mount.

 

In the end, I had to accept the shortcomings in the software and set my OTA to where EQAscom thought it was pointing. Not a very satisfactory result. But it got me going again!

 

[Merlin66]

Pete,

you can nominate an RA and Dec GOTO position in EQMod.

[pete_l]

52 minutes ago, Merlin66 said:

you can nominate an RA and Dec GOTO position in EQMod.

Thanks. Yes. The issue is that where EQMOD thinks it is pointing and where the mount is actually pointing are different, after the power dropped out. I can find no way to tell EQMOD that where it thinks the mount is pointing, is wrong.
A platesolve followed by a SYNC might do it, but I couldn't find a working plate solver app.

[spillage]

Odd you mention this. Around that time in the uk I had a similar issue with platesolve. Probably just coincidence. I if I was lucky the first image would platesovle but not the second one. I even rebooted everything and was about to give up. It then started to work as normal.  Im sure it was the user....

[Merlin66]

Pete,

there is a way of "accepting " external Sync points into EQmod/CDC.

I've done it a couple of times, but I can't access my computer to verify the process.

 

[alan4908]

4 hours ago, pete_l said:

A platesolve followed by a SYNC might do it, but I couldn't find a working plate solver app.

I use ACP which calls MaximDL which then calls Pinpoint. However, Pinpoint will generally fail to solve the plate if the error is large. If this happens, then ACP passes the request to astrometry.net for a blind solution. When the plate is solved ACP issues a synch command to the scope. 

A quick search on Google reveals a freeware solution that also uses astrometry.net and apparently can be interfaced to other programs, it doesn't require a connection to the internet:

http://www.astrogb.com/astrogb/All_Sky_Plate_Solver.html

Alan

[Merlin66]

ASPS is the one I have used.

very easy to set up and use.

Highly recommended.

 

[pete_l]

53 minutes ago, Merlin66 said:

ASPS is the one I have used.

Thank you thank you thank you!

THAT's what I'm talking about. Simple, well thought out, reliable, intuitive. It just works.

 

[Merlin66]

;-)

Glad to be of help.