Remote controller observatory

[PeterWar]

Hello everyone,
 
Our family owns a campsite located north east of Catalonia (Spain). I myself have been an amateur astronomer since  I joined the undergraduate Astronomy club at Harvard. After coming back home I cultivated my passion to the point where I became confident I could teach introductory astronomy lessons to kids and families of the campsite.
Little by little the interest has grown up and we get a lot of recurrent customers willing to learn more about this wonderful hobby (last observing sessions we were up to 300 people!.
 
So I've convinced the director (my brother) to step up investment on astro equipment to setup a fully automatized dome with a telescope that could be used on observing sessions for families and could also be rented for remote observations (ex. exoplanet photometry) during the off season months. The campsite already has all what's required, a private owned land with good views of a sky that's pretty dark (average SQM 21.00), electricity and internet access through wifi.
 
Our current requirements are as follows:
 
1-The observatory scope should carry a competent instrument for exoplanet photometry.
2-The observatory should be versatile enough to also be used for visual use on public viewing sessions of the sun, moon, planets and DSO. Public viewing sessions  using a projector and camera are also contemplated.
3-The observatory must be fully automatized so that I can control it from home.
4-The observatory should be an attractive instrument to be rented online by other people through service like itelescope in the off season months when I'm not controlling it remotely to allow from some payback of the investment.
5-Although we have people living in the campsite almost every day of the year, the observatory should be designed like a remote observatory, so the instruments should be protected against accidental sun exposure, rain and theft.
6-The observatory will be located next to a river on a typically humid area, so robust, reliable electronics are a must.
 
The plan is to use the following equipment (everything is up to debate, as long as other suggestions fulfill the requirements):
 
Dome: Fully authomatized SopeDome 3M cupola (shutter with 100cm), the idea is to mount it on top of a 4m width x 4 lenght x 1m height concrete base (we're pretty cost efficient pouring concrete this days in my country).

Mount: Software Bisque MEII Mount.

OTA: I noticed that the Meade 16" F8 ACF OTA is priced the same as the GSO 20" f8 RC OTA when one adds up all the dew heaters and motor focusers required for remote operation. Both could be carried just fine by the planned Software Bisque MEII Mount at a max weight of 109Kg).
 
I'm now assaulted by last minute doubts, in one hand, I love the spike free images that the Meade 16" would provide, both for visual and for AP. On the other hand, aperture rules for photometry and the GSO looks very tempting indeed, here's a list of pros and cons for each OTA:
 
Meade 16" F8 ACF OTA (Weight 40kg approx)
Smaller central obstruction 12.6% as a function of area
Better for visual
Easier cleaning/maintenance
Smaller light gathering power
 
GSO 20" f8 RC OTA (Weight 78Kg approx)
Bigger central obstruction 47% aprox as a function of area (EDIT: I think this was listed as a function of diameter, my guess is that it's about 22% as a function of area).
More light gathering power
Better for differential photometry?
Requires field flattener for larger CCD chips.

 

I would greatly appreciate some advice regarding the OTA. Thank you very much in advance.

[graemlourens]

Hi Peter.

You've got quite a project you want to start! I love it - especially because it will be so darn challenging....

I'd like to share my experience setting up a fully remote operated observatory that does unattended imaging. I also bought a Sopecome 3M (newest version) and couldn't be happier.

Dome:

The ScopeDome 3M is a very well engineered piece of equipment, and the brain behind it is Jacek Pala from Poland. I am in regular contact with him and any problem you might have, he will invest any time necessary to fix it, be it saturday or even sunday! I bow to his determination to deliver the best possible product. The assembly was done by ScopeDomeServices, Hans Gerritsen & Michael Suchodolski (whereby only Michael came for assembly and Hans was involved in the planning). I would not suggest to assemble yourself if you have never done it. It takes them (professionals) 2.5 days and most of it is spent on levelling everything so it runs smoothly.

The 3M in my case holds a small ED80 refractor with everything needed, and the space infront of the telescope is enough to walk around, but behind i can not walk there. Especially as you'll have lots of electronic boxes, computers, dehumidifiers etc. I doubt that the 3M is enough for imaging & viewing. Maybe you'll have to consider the larger 5.5 one (much more expensive though). Don't forget that the Pier is offset to the south, so not in the center of the obsy.

All in all i can only recommend the ScopeDome highly as well as the team that assembled it of Michael. It does come with some cost though

Here a picture so you can imagine the space you'll have:

I also made a concrete ring to higher the dome. It has several advantages. You will have space for electronics, cables, boxes, computers, ups etc and you have more than enough space so you don't feel 'cramped' in the height. Furthermore there are less water / humidity issues if you isolate well enough. P.s. making that concrete ring wasn't terribly easy for our construction company. They're more used to making things square  And be careful that its perfectly level, if its off too much, you'll have no chance of having the dome run smoothly. This foundation is crucial.

Here's still an outside view.

Safety:

- Obviously a UPS device is a must. Nothing huge necessary, but with a fast 'switching time' (not sure how you call it) so there is absolutely no loss of power while going von AC to DC->AC
- Weather station i use the very reliable AAG Cloudwatcher that can be connected directly to the ScopeDome Electronics so that in emergencies the Shutter will close by hardwired signal, even if the software fails. (The same btw is concerning power failure, you can tell the observatory to close, when it switches to UPS, so your UPS just needs enough power to shut everything down.)
- Humidity in my case (located in Poland) is an issue, so i have a dehumidifier (based on desiccant system, others will not work in low temperatures) running 24/7. The cost is nothing compared to the equipment you're putting in there and constant high moisture will kill everything in time.
- I have located 2 moveable cameras (IR) in the dome,  so at any point in time (even when imaging, and without disturbing the imaging) i can see what is going on (Mount, Cables, Shutter etc)
- You'll have to build in multiple failover systems if you are not close to the observatory like in my case. I have a second computer that does nothing else than can restart the first computer (full power shutdown & restart) in case the first one freezes (and it does happen sadly with windows!). Further i have the same failover for Network connectivity. There are lots more of these nifty things i found out after travelling too many times to the obsy to reset something that i'm happy to share if you want to.
 

Mount & OTA i can not give you any recommendation, i'll leave that up to others

Kind regards, Graem

 

[dokeeffe]

Wow thats an interesting project.

I have setup my observatory for 'remote use' and been using it for the last year or so. There are a lot of challenges!!! However we measured our first exoplanet transit there last month.

When I say 'remote use' though its actually just a 1hr drive so its not too difficult to debug issues. I'm using a celestron CPC1100 with atik ccd equipment inside a roll off roof. Everything is controlled by INDI and some custom scripts/applications. If I were to go back and start again, I would choose a slightly smaller telescope and a much better mount. I think your mount choice is a good one. One thing worth having a peek at is the setups that itelescope.net use. They must have been through all the pain of setting up remote scopes so whatever equipment they choose for recent scope additions must be based on fairly solid experience.

BTW, do you have any plans to 'rent' scope space? I'm seriously considering moving my setup to somewhere drier than Ireland..... If you ever do, I would be interested :-)

Derek

[PeterWar]

Graem, thank you very much for your great feedback. We plan to build the dome on top of a 4x4m concrete base with walls 1.5m in high, so there will be more space to get around.

Derek, I'm sending you a PM.

[graemlourens]

6 hours ago, PeterWar said:

Graem, thank you very much for your great feedback. We plan to build the dome on top of a 4x4m concrete base with walls 1.5m in high, so there will be more space to get around.

Derek, I'm sending you a PM.

Ah, sorry i missed that 1 meter high info! I too have a approx 4x4m concrete base btw and just a hint there, make it slightly 'sloped' so that water doesn't pool around the ring. We did not do that and water pooled around the obsy, letting water soak into the cement constantly, giving lots of extra unnecessary humidity. Or you will have to seal the cement (inside & outside).

[PeterWar]

6 hours ago, graemlourens said:

Ah, sorry i missed that 1 meter high info! I too have a approx 4x4m concrete base btw and just a hint there, make it slightly 'sloped' so that water doesn't pool around the ring. We did not do that and water pooled around the obsy, letting water soak into the cement constantly, giving lots of extra unnecessary humidity. Or you will have to seal the cement (inside & outside).

Your experience is very usefull to us, we'll definitelly create a slope to drain water. Also, what is the de-humidifier that you are using? idieally we would like to setup one that could be controlled remotely. I'm also interested in your webcam setup, I was planning to buy a Reolink RLC410 4MP night vision camera at amazon to do the job, but there might be better choices.

Finally, if we create a 4x4x1.5m base and allow to get all the equipment except for the scope out of the way of the cilinder, how many people would you say we'll able to accomodate during a viewing session?

[graemlourens]

1 minute ago, PeterWar said:

Your experience is very usefull to us, we'll definitelly create a slope to drain water. Also, what is the de-humidifier that you are using? idieally we would like to setup one that could be controlled remotely. I'm also interested in your webcam setup, I was planning to buy a Reolink RLC410 4MP night vision camera at amazon to do the job, but there might be better choices.

Finally, if we create a 4x4x1.5m base and allow to get all the equipment except for the scope out of the way of the cilinder, how many people would you say we'll able to accomodate during a viewing session?

Hi Peter

I'm using this one here: https://www.amazon.co.uk/Meaco-DD8L-Junior-Desiccant-Dehumidifier/dp/B0060MY2KQ . It has been running for 1.5 years without stopping or having any issues. The most important thing with the dehumidifier is that even after power loss, when power is back (either you switched it on remotely or power restored itsself) that it restarts where it left off. My first purchase of dehumidifier i didn't think about that, and after first power loss i had to drive to the obsy to turn it on again  This dehumidifier also can automatically switch on/off based on certain humidity levels, saving you energy in the long run and obviously has an endless drain system with overflow-protection if the drain would be blocked (like it has been in my case when the ground freezes).

Concerning remote power on/off i am using multiple of these: http://creotech.pl/pl/produkt/cti-ps6-m-2/ It was recommended me by Jacek himself of Scopedome that has used this power strip for years without problems. It has its own webinterface, schedules, and an 'API' so a developer (like i am) can steer it from his own software (in my case i have made a software that will turn on / off the dehumidifier based on humidity levels, little more intelligent than the dehumidifier does by itsself)

Security cameras: Even if the obsy is considered 'outside' i took indoor cameras (MUCH less expensive). They have served me well for 1.5 years and despite horrible temperatures of +40 degrees vs -24 degrees never let me down. I took these ones here, simple and effective. Also have an 'API' so programmable (i also made my own software to grab certain timeintervals for timelapses etc) https://www.amazon.com/Foscam-FI9821P-Wireless-Camera-Storage/dp/B018K9YXZU/ref=sr_1_1?s=photo&ie=UTF8&qid=1481720952&sr=1-1&keywords=fi9821p+v2

I would though like a larger view (degrees) inside the obsy. With those cameras i have, i can only see one thing at a time (mount for example). So a widefield (fisheye) lense would be more appropriate. Depends on what you want to 'observe'.

Concerning cameras, also what i learnt is that i wanted a camera mounted on the Telescope itsself, pointing in the direction where the telescope is pointing. With these domes, the calculation of azimuth based on the EQ values, does need some tweaking, especially when you're pointing very high in the sky (>80 degrees). This helps a lot in determining 'why the heck did i loose my guide star' just to see you're pointing in the side of the obsy wall!

Concerning how many people:

I'd be surprised if you can have more then 2 visitors and yourself in there at once and still move freely. But this is assuming you only occupy 60% of the are, as the other 40 will be filled with boxes, computers etc (as you'll have to put them somewhere...). But again, i've never used it for visual, and it really depends if you have a dob in there or refractor as the viewing positions will be totally different.

If you have any other questions, ask away! I was dying to share this info lately  Didn't get round to making some kind of journal, maybe i should still...

P.s. hope there are no spelling mistakes, i quickly had to write this up during work...

Kind regards, Graem

 

[andrew s]

15 hours ago, PeterWar said:

Graem, thank you very much for your great feedback. We plan to build the dome on top of a 4x4m concrete base with walls 1.5m in high, so there will be more space to get around.

Derek, I'm sending you a PM.

If the wall is concrete as well than that is a lot of mass to heat up during the day and provide thermals in the night could you use a more light weight but strong construction for the walls?

Similarly you could just use a concrete ring to support the dome foundations with a wood decking for the external and internal flooring.

Just some thoughts as it gets hot in Spain!

Regards Andrew

[PeterWar]

On 14/12/2016 at 14:14, graemlourens said:

Hi Peter

I'm using this one here: https://www.amazon.co.uk/Meaco-DD8L-Junior-Desiccant-Dehumidifier/dp/B0060MY2KQ . It has been running for 1.5 years without stopping or having any issues. The most important thing with the dehumidifier is that even after power loss, when power is back (either you switched it on remotely or power restored itsself) that it restarts where it left off. My first purchase of dehumidifier i didn't think about that, and after first power loss i had to drive to the obsy to turn it on again  This dehumidifier also can automatically switch on/off based on certain humidity levels, saving you energy in the long run and obviously has an endless drain system with overflow-protection if the drain would be blocked (like it has been in my case when the ground freezes).

Concerning remote power on/off i am using multiple of these: http://creotech.pl/pl/produkt/cti-ps6-m-2/ It was recommended me by Jacek himself of Scopedome that has used this power strip for years without problems. It has its own webinterface, schedules, and an 'API' so a developer (like i am) can steer it from his own software (in my case i have made a software that will turn on / off the dehumidifier based on humidity levels, little more intelligent than the dehumidifier does by itsself)

Security cameras: Even if the obsy is considered 'outside' i took indoor cameras (MUCH less expensive). They have served me well for 1.5 years and despite horrible temperatures of +40 degrees vs -24 degrees never let me down. I took these ones here, simple and effective. Also have an 'API' so programmable (i also made my own software to grab certain timeintervals for timelapses etc) https://www.amazon.com/Foscam-FI9821P-Wireless-Camera-Storage/dp/B018K9YXZU/ref=sr_1_1?s=photo&ie=UTF8&qid=1481720952&sr=1-1&keywords=fi9821p+v2

I would though like a larger view (degrees) inside the obsy. With those cameras i have, i can only see one thing at a time (mount for example). So a widefield (fisheye) lense would be more appropriate. Depends on what you want to 'observe'.

Concerning cameras, also what i learnt is that i wanted a camera mounted on the Telescope itsself, pointing in the direction where the telescope is pointing. With these domes, the calculation of azimuth based on the EQ values, does need some tweaking, especially when you're pointing very high in the sky (>80 degrees). This helps a lot in determining 'why the heck did i loose my guide star' just to see you're pointing in the side of the obsy wall!

Concerning how many people:

I'd be surprised if you can have more then 2 visitors and yourself in there at once and still move freely. But this is assuming you only occupy 60% of the are, as the other 40 will be filled with boxes, computers etc (as you'll have to put them somewhere...). But again, i've never used it for visual, and it really depends if you have a dob in there or refractor as the viewing positions will be totally different.

If you have any other questions, ask away! I was dying to share this info lately  Didn't get round to making some kind of journal, maybe i should still...

P.s. hope there are no spelling mistakes, i quickly had to write this up during work...

Kind regards, Graem

 

Graem, I'm curious about how your dome does the meridian flip, do you have uninterrumped views of the sky at the zenith during the meridian flip? 

 

Andrew, we'll avoid concrete as much as possible, thank you for your comments.

[steppenwolf]

Quote

how your dome does the meridian flip, do you have uninterrumped views of the sky at the zenith during the meridian flip? 

On my robotic observatory, at meridian flip time, a plate solve is taken, the dome's azimuth controller is uncoupled, the mount does the flip then couples to the dome again. When the dome has revolved to the correct position, a second plate solve is carried out and off she goes.

[PeterWar]

1 hour ago, steppenwolf said:

On my robotic observatory, at meridian flip time, a plate solve is taken, the dome's azimuth controller is uncoupled, the mount does the flip then couples to the dome again. When the dome has revolved to the correct position, a second plate solve is carried out and off she goes.

The projected Paramount ME II mount has the ability to track 30 degrees past the meridian without doing the flip, this is important for exoplanet photometry as you don't want to flip in the middle of a transit. I just want to know if the dome zenital view is clear and that the dome is able yo flip without interrumping the view of the sky.

[steppenwolf]

I have just realised that you have already made your choice of dome so I don't have much to bring to the table on this one - hopefully Graem can answer your question for you. Good luck with your project.

[ollypenrice]

I would keep away from the 16 inch Meade on grounds of optical quality. Imagers wanting to rent time on scopes of this class really do want seriously good optics. The Meade optics which I have seen are not at the level people are looking for. I think you'll also have a terrible time trying to get the Meade to thermal equilibrium and the damp will be an issue on the corrector plate. A Plane Wave would be a far better idea.

I'm not entirely sure about your observing projects but one thing I avoid like the plague is making my kit 'multi task.' Once it is all tickled up and working sweetly for imaging I don't want to touch it at all. It stays just as it is and I do other activities (I work with the public as well) on different instruments. The need to redo flats, for instance, adds quite a lot of work. Changes to balance will inevitably have knock on effects on your guiding - and so on and on.

At the Observatoire des Baronnies near my place they have a huge RC (0.8 metre) on a research grade Alt Az mount with field derotator. However, they have two points of focus to choose from, an EP on one side and a CCD on the other.

For photometry you'll need a linear response camera which means having no anti blooming gate. This obviously will have a big impact on non scientific imaging. I'm not sure how modern recreational imagers would feel about bleed lines but I wouldn't want them myself.

My biggest concern, though, centres upon the difficutlies of setting up a single instrument to do different jobs. Don't under estimate how complex this is.

Olly

[andrew s]

3 hours ago, ollypenrice said:

For photometry you'll need a linear response camera which means having no anti blooming gate (ABG). This obviously will have a big impact on non scientific imaging.

While I fully support all most all of what Olly says above, you can, and many do, do quality photometry and spectroscopy using CCDs with ABG. The key is to characteristic your CCD so you know where the linear region is and where the ABG cuts in. I use Sony sensors on my low resolution spectrograph (Atik 414Ex) and on my echelle medium resolution spectrograph (SXVR 694) both are very linear until close to saturation. As with all scientific CCD work you need to use bias, darks etc. to extract the science data.

Regards Andrew

PS if you add a Star Analyser 200 to your filter wheel you can easily do slitless spectroscopy . See here http://www.shelyak.com/rubrique.php?id_rubrique=4 and http://www.threehillsobservatory.co.uk/astro/spectroscopy.htm

[ollypenrice]

1 minute ago, andrew s said:

While fully support all most all of what Olly says above, you can, and many do, do quality photometry and spectroscopy using CCDs with ABG. The key is to characteristic your CCD so you know where the linear region is and where the ABG cuts in. I use Sony sensors on my low resolution spectrograph (Atik 414Ex) and on my echelle medium resolution spectrograph (SXVR 694) both are very linear until close to saturation. As with all scientific CCD work you need to use bias, darks etc. to extract the science data.

Regards Andrew

I didn't know that, Andrew. It's interesting. I know that at the Obs des Baronnies they do use a camera without ABG so I assumed it was still considered necessary. (They do a lot of exoplanet surveys there, too.)

Olly 

[andrew s]

Olly I started down that route too with an expensive E2V chip front illuminated and no ABG but the higher QE and dynamic range were at the expense of higher read noise and dark current. In typical amateur setups the Sony chips deliver better S/N and fainter magnitude. The pro's still use E2V and other similar chips but they often have much better cooling (liquid N2) and electronics. They often have much bigger scopes with longer focal lengths where bigger pixels are more efficient.

Regards Andrew

[graemlourens]

On 12/16/2016 at 13:32, PeterWar said:

Graem, I'm curious about how your dome does the meridian flip, do you have uninterrumped views of the sky at the zenith during the meridian flip? 

 

Andrew, we'll avoid concrete as much as possible, thank you for your comments.

Peter, i'm sorry, somehow i didn't get the notification that you quoted me.

Indeed this is a tricky one. Theoretically everything works. The dome shutter on the scopedome is constructed so that looking straight up, you have clear view, though i do not know until what aperture. But even with my piggypacked ST80 it is no problem.

The tricky part is the software that is controlling (in my case SGP) where the dome should point, and indeed i have had to trial and error a lot with the settings there (offsets etc) to get it right. The biggest problem is that at such high altitudes, small telescope movements, can cause the observatory to turn 180 degrees, as this takes a lot of time (even if the scopedome i think is rather fast in azimuth) you will have to have a long waiting period (i have set mine to 30 seconds) to allow the dome to slew wherever it has to go. The Scopedome software ittself does this job perfectly, but you can not use it as the imaging software needs to control the dome. I guess my settings are just not as great yet, but thats got nothing to to with the dome.

UPDATE***: With the latest SGP Version SGP waits for the dome to complete the slew before it continues, it seems i had a pretty old version . Excessive mount settling times are then not necessary anymore.

In SGP and in probably most other softwares as well you have a 'mount settling time', i have used this, and set it to 30 seconds, (even if its not the mount that has to settle, its the dome ) i guess in more sophisticated softwares like the SkyX & co there will probably be less challenges with these kind of things.

I also set that i'm only flipping 3 minutes past the meridian.

Kind regards, Graem

[graemlourens]

On 12/16/2016 at 13:54, steppenwolf said:

On my robotic observatory, at meridian flip time, a plate solve is taken, the dome's azimuth controller is uncoupled, the mount does the flip then couples to the dome again. When the dome has revolved to the correct position, a second plate solve is carried out and off she goes.

Steve, What Software is controlling your sequences?

Based on your other thread i guess its still CCD Commander, and i'm trying to find out how you manage to restart the sequence when clear skies arrive again. Especially i'm interested in your experiences with that, but i'll PM you about this as its a different topic.

Kind regards, Graem

[steppenwolf]

I do indeed still use CCD Commander as it does all that I require with an amazing amount of control over the whole imaging process but as it is closely interfaced with MaxIm DL it may not be for everyone.

I look forward to your PM.

[PeterWar]

On 16/12/2016 at 15:20, PeterWar said:

nt for exoplanet photometry as you don't want to flip in the middle of a transit. I just want to know if the dome zenital view is clear and that the

Just wanted to post a quick update on the progress done, we're now assessing different options but we had to increase the budget to consider a bigger dome, Graem you were absolutely right on pointing that the Scopedome 3M might be too tight for public observations.

 

We're now considering the Scopedome 4M and the Baader Planetharium All Sky 4.5M dome.

 

Regarding the optics, the Meade 16" F8 OTA is quite overpriced in Spain, because of this reason, we're assessing the possibility to adquire an Orion Optics ODK16 or a GSO 16" RC instead.