Friday, May 26, 2017

High Humidity and More Frosting Issues.

Last night I went out to Kumeu Observatory around 7 pm, Steve wasn't free so I set about testing out the camera in the hopes that by cooking the desiccant I would have solved our frosting problems, unfortunately as I cooled down the camera I saw halos start to develop around the stars and after just ten or so minutes I started to see the tell tale signs of frost starting to form, while I was working in the observatory I had set up my DSLR outside to capture a startrail and after going over the images today I noticed quite a bit of thin cloud that was invisible to the naked eye but was clearly captured by the camera, so maybe some of the halos I was seeing may have been caused by the clouds although the tell tale signs of frosting are really quite distinctive and can't really be mistaken for anything else.


Halos around the stars after cooling down the CCD ^

The problem with the halos must have been in camera though because when I warmed up the camera the halos all went away and when I cooled down the camera they quickly came back, I had read online that after cooking the desiccant it may take a day or two for the desiccant to absorb all the moisture from the camera so maybe there just hasn't been enough time for the desiccant to do it's job or perhaps it's time to buy a new desiccant, we can't really do anything below zero degrees Celsius at the moment as you start to develop the halos below that temperature and once you have the halos they tend to effect being able to obtain good focus, I noticed that the weather station was reporting that the humidity was at 90% so I think this may have been a factor also, when I shut down the dome later on in the night the shutter was literally dripping wet! I also did some tests of running the camera at zero degrees Celsius for an hour or so and then cooling it down as me and Steve had read that in an online forum as being a possible solution to the problem but to no avail as soon as the camera was set to -20 you would see the halos start to form followed by frost in the 5-10 minutes after cool down, we will have to find a solution to our frosting issues quickly as the microlensing season is fast approaching.


Startrail looking south over the Wasp Observatory that I took while working in Kumeu Observatory. ^

I stuck it out until 2 am doing some pointing tests by astrometricaly solving images with the Image Link function in the Sky X, using this technique I could easily find variable stars such as AR Sco, so we will probably just use this method until we can get a really robust pointing model done, by 2 am the clouds had inevitably rolled in and put an end to the nights observations.

Posted by Jonathan Green.

Monday, May 22, 2017

Ice and Clean

After the adventures in collimation of the night before, another clear night saw Jonathan and I again off to Kumeu (missing out on the AAS film night).  Jonathan was out there first and was quickly frustrated once again by frosting on the CCD sensor.  After a couple of "warm up" and "cool down" cycles still hadn't fixed it, it was clear this problem was going to start getting annoying rather fast.

Cleaning the corrector plate on the C14
After I arrived, we decided to leave the camera with the coolers off for a while and tackle another little job that's been on the list for far too long - the C14 corrector plate.  We haven't cleaned the corrector at all since we started (a long long time ago....) so you can imagine the quantity of dust, water spots, insect gunk and all manner of things on there. (Actually you don't need to imagine - we've got quite a few pics of the corrector on the blog!)

I'll get you....dust particles... 
Using the old faithful technique of a bulb blower,  soft white tissue and 30% alcohol solution in demineralised water, the outside surface of the corrector was slowly and carefully de-gunked  - which had the predictable effect of showing just how much gunk was on the inside of the corrector - this will have to be addressed in the short term.  A medium term project might also be to get the primary cleaned (I know people have had fantastic results using the novel cleaning kit from https://www.photoniccleaning.com/)  or potentially re-aluminized - as there is an appreciable quantity of dust and a small mould/fungal spot.

Dismantling the filter wheel on the SBIG ST10XME
We also checked out the filters, as we know the new RGB we were testing needed to be tightened up - but also noticed the L and the #12 Wratten filter were looking past their best too...  after pulling the flter wheel out it was clear that the L and #12 filters would definitely be causing issues with our images.  Even though we are planning to replace these filters, these too had a very careful cleaning and came out looking much better than they were originally.
Carefully cleaning the L filter

We reattached the camera and cooled it down, only to be instantly frustrated by frosting again almost immediately.  We are definitely going to "cook" the dessicant pack again, as it's clear there is obviously moisture in the system that's not being removed.  We jumped on the internet (via Steve's phone as we've not get this sorted yet still) and learned a couple of interesting things about this problem:
  1. you can buy a replacement dessicant plug that takes disposable gel packs - this is fantastic as it would allow us to replace the dessicant quickly without the "cooking" process
  2. A technique described on a forum for cooling down in stages to avoid the frost. 
We gave #2 a go and cooled the chip to zero for half an hour before taking it any colder - this seemed to do the trick (though it might have just been luck this time) as we managed to cool further without seeing any frosting.  We'll certainly add this to our process for the future to see if this will avoid this situation.  

One final challenge for the night is that the focal reducer we have is also in dire need of replacement/professional cleaning or removal - though at this point we noted that we don't have the original 2" nosepiece- something else for our shopping list.

After I left around 12:30, all Jonathan did  was try image for a while but soon got hit with more frosting issues so frustrated, packed down and cleaned up the observatory including removing a dead mouse from under the dome ( gross but at least we know the rat bait is effective ), Jonathan ended up taking the desiccant home and cooked it (it goes in the oven for 4 hours to dry out the dessicant material) the next day. He then took it back out to Kumeu and reinstalled into the CCD camera, hopefully that should resolve our frosting issues for a while.

Steve and Jonathan

Sunday, May 21, 2017

Collimation

Dew on the inside of the corrector plate
Last night Jonathan & Steve met up at Kumeu Observatory to take advantage of the clear skies and get to work on collimating the "Nustrini" C14, Jonathan arrived first and while waiting for Steve set about focusing the camera and doing some pointing tests, from the outset he was hit with frosting on the CCD, this happened 4 times before we decided to run the camera at -15 instead of -20, this seemed to resolve our frosting issues on the night but what is certain is that we either need to cook the desiccant again or replace it with a new one, also had an issue with dew on the inside of the corrector plate again and found this was due to the dew strap not being warm all the way around, it looks like we are using a dew strap that is not designed for a C14, so after adjusting the dew strap so it was providing heat to the affected area and taking off some of the masking tape over the vents so that we could air out the optical tube, thankfully this seemed to to do the trick as the dew eventually disappeared. Grant at Stardome has experience a similar problem with dew on the inside of the corrector - whilst sealing any small holes is great to prevent dust setting into the system it is also preventing adequate ventilation, and any humid air in the tube is unable to be circulated out.


CCD Inspectors's Single Star Collimation 
.After Steve arrived we set about collimating the telescope, we used CCD inspector and defocused a single star into an annulus.  It appears we don't have enough "travel" on the TCF focuser to defocus the star enough, so we needed to manually defocus to get the start image big enough for the CCDInspector process.

Starting off by identifying where on the image the collimation screws were in relation to the image (by making a shadow with my hand) it was easy to see which screw to adjust - basically the one which "moves" the image in the direction of the line on screen.

After making the corrections that CCD inspector gave us we improved the collimation then moved onto using the multi star collimation feature of CCD inspector, we used an open star cluster near the zenith but after a few attempts we ended up making the collimation worse so ended up having to star over !

Steve Hennerley collimating the "Nustrini" C14.
When we did start over though, and had to manually refocus and start again with the single star, we learned that our "shipping bolts" we installed to combat "mirror flop" may be causing us more problems than they are solving.  If we leave them loose enough so they don't interfere with the mirror, they are probably ineffective, and we've noticed they loosen up as we slew around (as the mirror cell is moving we guess).  If we tighten them however (or more correctly, tighten the focus against them) then there is a significant deflection of the mirror affecting collimation.  The shipping bolts are not opposite each other - rather they are 120degrees apart and opposite the focuser (if you imagine the CCD inspector picture of the collimation screws above as being the back of the scope, the focuser is at "A" and the two bolts are at "B" and "C").  This has the end result that the mirror is pivoted along the A to "B-C midpoint" axis.   This may need revisiting - but for now we left the bolts "just" touching the mirror cell.

We ended up collimating the telescope until about almost 3 am in the morning, we could definitely see a huge improvement in the images and the shape of the stars, after Steve left Jonathan managed to focus a star near the zenith at a FWHM of 1.7 arc seconds per pixel, after taking a few test shots he could really see how improved the images were but we will need to monitor the situation because if the primary mirror is flopping we can expect the collimation to degrade fairly quickly, with another clear night tonight Jonathan and Steve plan to catch up again and see what else can be done in preparation for the forthcoming microlensing season.




Posted by Jonathan Green & Steve Hennerley.

Monday, May 8, 2017

Cables....Be Gone !!!

Even though the skies weren't particularly clear this evening, Jonathan and I headed out to the observatory to tackle a few jobs that were on the list. A critical job that needed doing was to reconnect the dew strap to 12v power.  Since we'd replaced the mount electronics, the dew strap power couldn't actually be hooked up as the power had been routed through the original mount wiring (pretty much the only thing that was).

I wasn't keen on a temporary fix (we all know how these have a habit of becoming permanent) - and a "dream" of mine since we installed the paramount was to get as much of the cabling as we could to use "through mount" cabling to eliminate the risky "cable snake" that carried signal and power to the scope equipment.

Indeed when we rebuilt the mount, we were already supplied with the standard SoftwareBisque connector panel -  this was prewired with USB, a multipole pass thorugh power connector 5v and 12v outputs (though low current - we weren't too comfortable trying to drive the heater with the 12v).  We worked out this was almost enough for us to connect everything we needed bar a couple of items - one of which was the dew heater.

Custom wiring box on the mount dovetail plate
In the end we added to this two "network" sockets (connected with Cat5E cable) and two DC power sockets (locking 2 pin connectors) neatly mounted to the dovetail plate in a 3D printed enclosure. This provided all the connectivity we needed now, plus a little room for changes and expansion as we broaden our astronomical horizons.

in theory therefore, all that was required was making up a few cable connectors and we'd be to enjoy a cable-snake-less future....   Step one though is that we hadn't quite worked out the best (ie tidiest) way to get power into our extra power cables.  There were a number of spare "keystone" type connectors in the mount side panel we could have used - but unfortunately the locking connectors we used at the scope side were too big to fit.  We were originally planning to use "Anderson Power Pole" connectors but they didn't have an elegant panel mount solution.

The mount control panel showing our
newly installed Anderson PowerPole
connectors (top centre)
In the end the 3D modelling software and 3d printer again came to the rescue and we manufactured a custom "keystone" style mounting bracket for a pair of "PP30" connectors.  After adding further PP30 connectors to the lead from our 12V power supply (which would have been easier with the correct crimping tool for the job!) , and the appropriate 2 pin connector to the lead to the dew heater we were finally ready to test.  The dew strap (controlled by a PWM controller designed to handle LED lights) heated up properly and we were back in business to fight the dew. (if only it had been powerful enough to evaporate the clouds that had started gathering thickly!)

How many parts?
Of course one win doesn't make a successful evening - and with one device fully cabled up through our new mount wiring, sights were set on the rest of them!  Next in line was the biggest chunkiest cable - the power supply to our SBIG ST10XME camera.  From research this unit couldn't be driven from just 12v - the power supply has +12v -12v and +5v all supplied though a "DIN" style connector.

Making the cable connectors
The plan for this was to route through the small "Kycon" 4 pin connector in the SoftwareBisque wiring loom (labelled "power in" on the pic above).  this meant making up two adapter leads with DIN connectors on one end and "Kycon" on the other.  The DIN connectors were straightforward enough (once I'd checked, diagrammed, double checked and tested the pin layout) - but the Kycon connectors must be the fiddliest, most over-engineered plug on the planet.  It is supplied in no less than 8 individual parts, all in separate plastic baggies and a set of instructions.  The first one took some time to carefully assemble - though by the time I got to the second it was admittedly not quite as challenging.

Whilst it was a little nerve wracking to plug the new connector into the camera (even after double checking the polarity and voltage of the 3 voltage line pins), happily everything worked as it should have done and the camera spun up nicely.  The only remaining piece of equipment to handle was our Optec TCF Focuser.

As luck would have it, this one was probably the easiest.  The focuser connects to the controller by way of a 9 pin "D" plug cables to a modular RJ45 socket.  As a career geek, I've always got a handful of RJ-45s and a crimper at hand, so this was a 2 minute chop the wire smaller and connect on a new plug (which was even cabled as standard "T-568-B Spec").  Adding a small Cat5 patch cord at the control panel end and suddenly a long time dream was just about reality!

All that remained was to tidy and tie up the wring to keep it need and free from snagging on anything and to double check all our connections, and - importantly - to make sure everything still worked..

The process of moving from externally cabled equipment to using a "through mount" approach has taken a lot of planning - even at the early stages when we were tearing out the old control gear from the mount.  We needed to have our dovetail plate machined to take extra cables, and even create custom connector boxes.  Even with everything in place there was a bit of research required for the final cabling and it took a good few hours just to get everything built and plugged in.

The end result though is that now, as well as a much neater set up, we are free from the worry of the cables dragging on the floor or snagging on something - or of course one of us tripping on it.  We've also reduced the risk of damage to the cables, or a connector.

Steve


The end result - notice that all the cabling to the OTA now goes to the dovetail palte connector boxes.

6th-7th of May, Clouds and CCD Frost.

On the 6th of May I headed out to the observatory after sundown to be pleasantly surprised to find that the Wasp Observatory was open, Nicola Gujer was there using the University of Auckland's Department of Physics Meade 12' Inch LX200 Schmidt–Cassegrain to capture data for her project to study the astronomical "seeing" in Auckland, after setting up I went to focused on a few stars only to find I was getting some pretty bad results, after realising that I wasn't pointing the telescope high enough I managed to focus a star with a FWHM of 1.8 arc seconds per pixel, after finding an interesting target to image I noticed some strange features on the images, I think some of the early ones could have been ice starting to form and I was sure of it later on when the familiar arcs appeared, knowing that the only way to fix this was to "warm up" the camera, I did so and confirmed that the aberrations on the images were indeed caused by CCD frosting, the thing was I had to "warm up" the camera about three times before the problem went away entirely so i think we may have to cook the desiccant again.


NGC 2997 with the 1st signs of frost starting to form.(note that the image is uncalibrated and was also affected by the gibbous Moon.) ^

The Star that Nicola was monitoring went behind the trees so she packed up and headed home around 11 pm, after she left I started imaging part of the Lobster Nebula (NGC 6357), I captured around half an hours worth of data before the clouds started to arrive, I tried to wait them out but they were very consistent, it was very frustrating as I could tell the rest of Auckland was in the clear, the clouds were coming in from the west and not getting much further in before thinning out and dispersing, while I waited I got the vacuum cleaner out and gave the observatory a good clean up, after packing down I left the observatory around 2 am.


Part of the Lobster Nebula (NGC 6357) ^

I also went out to the observatory on Sunday night (7th) but got clouded out before I could get much done, I looked at the cloud sensor downstairs and noticed I had made the right decision leaving the previous night as the sensor showed that the sky didn't clear until 6 am!

Posted by Jonathan Green

Saturday, May 6, 2017

Documentation, Guiding, and "Point Telescope Here"

After a few rainy nights, the clouds cleared and another opportunity came up to knock off a few tasks. I arrived the site a little earlier than Jonathan and as I was starting things up, started to produce our "SOP" (Standard Operating Procedure) documentation.  By documenting our startup, operation and shutdown procedures we will ultimately make it easier to train others into using the site - and more importantly have a consistent way of doing things.  This also allows us to document little used procedures to save "head scratching" time when we need to use them again.

So we now have the bones of the Startup, Guiding and also "Point Telescope Here" documentation.

Cats Paw - 40 mins exposure (2 min subs)
The 'PTH' process is one that we were really happy to get working the last time we were set up - this allows us to centre an object in our field, if it's slightly off to one side say, just by clicking the point in the image that we are interested in.  The mount automatically tweaks it's alignment to get your desired target dead centre.

It's not a particularly hard process to get working - in fact when we first did it we were surprised we had taken so long to get it working.  It was so easy in fact that we didn't bother writing down what we'd done.   Needless to say, it wasn't working in the  new setup, and we couldn't quite remember the simple steps we needed to do!!

After requisite head scratching, it was indeed really easy to do - so I did it - but more importantly, I also wrote down how I did it so that next time it will be much faster!

Whilst working on this we also discovered the cause of the guiding woes from earlier in the week - it looks like it was just an extra "calibrate" that might have been needed to fix the problems!  We had guiding working just fine in all the areas we tried.

Since Jonathan had enjoyed the remote operation experience so much, I also improved the monitor setup down in the bunkroom - there are now two bigger monitors to use which makes operation all that much easier.

The other major task completed tonight was another improvement on out polar alignment by doing a few more rounds of drift alignment.  We have got rid of almost all the drift but still see more East/West movement than we are expecting - this possibly needs more investigation (could be just PE) but it's so slow that the autoguider will take care of it fully for now.

There was a little light cloud around so our test imaging wasn't particularly great and we are desperately in need of collimation.  We have found out there is to be some microlensing work to complete next month so the race is now on to get these tasks - along with checking out the filters and focal reducer - knocked off before then.

Wednesday, May 3, 2017

2nd - 3rd of May, Cold Clear Skies!

I didn't get out to Kumeu as early as I would have liked last night as I helped to host a talk by the co-creator of the PhotoPills app Rafael Pons at Stardome Observatory on behalf of the Auckland Astronomical Society, after the talk was finished I gave Rafael a quick tour of the facilities and then dropped him off at the backpackers he was staying at and headed out to the observatory. On arrival I was pleasantly surprised to find Auckland Astronomical Society member Alan Kane on site observing with his big Dobsonian, after exchanging pleasantries I opened up the dome and got to work.

The first thing I did was obtain focus using the TCF's auto-focus procedure this worked very well with a focus star giving me a result of a FWHM of 1.6 arc seconds per pixel, I then set about slewing to different objects and taking some test images but after a while I noticed that the TCF wasn't tracking the temperature changes so the focus had shifted off a bit, the temperature had dropped by about two degrees so when I went to run another autofocus I found that I could no longer obtain focus as the TCF wanted to go past 7000 steps when looking for the autofocus start position, knowing that the solution was to put the TCF back to the 3500 half way point and then manually get the focus back to as tight as I could by eye, I finally got back into focus although the focus Star I was now measuring was only giving me a result of a FWHM of 2.3 arc seconds per pixel, I don't know if that was because the "seeing" had changed or because having re-set the focus manually I had somehow changed the collimation.


- A stack of ten one minute exposures of the spiral galaxy NGC 5247, I think in this image the focus was already starting to go "Pear" shaped.

Imaging targets around the sky using the auto-guider I noticed that objects in the east couldn't be autoguided as the target stars were drifting off fairly rapidly, on the western side of the sky their was no problem at all so I think we really do need to do a lot more drift alignment to make sure we can autoguide on both sides of the sky, at this stage of the night I noticed the star shapes looked a bit funny ( not quite round ) I wondered if maybe the collimation had slipped out, but after a bit of investigation I found that we had dew forming on the inside of the corrector plate! I had encountered this the night before when hanging out with Grant Christie at Stardome while sitting in on his observations of a binary Wolf-Rayet star system, I knew that the solution was to crank up the dew strap to heat up the corrector plate but unfortunately our dew strap is not currently powered, I remembered Steve saying he had to think about how we are going to power it moving forward, so not wanting more dew to form on the inside of the corrector plate I shut down and headed home around 2:30 am, I've got to say I'm very thankful that Steve had setup the computer downstairs to control the dome computer remotely, so that I could operate in comfort, as on the way home I noticed my car's outside temperature sensor was recording the outside temperature at a chilly 3 degrees!


- Dew on the inside of the corrector plate.

So moving forward I think we have a number of tasks to prioritize before we can start doing some research grade observations, we obviously really need to get the dew strap powered! With the cold / damp weather here now it won't take long for dew to form on the corrector plate, we also really need to take the CCD off the mount and make sure the new filters are not moving, if the filters move even slightly we won't be able to do the data reduction correctly and with the microlensing season about to start we really need to make sure our data is reduced correctly for scientific submission and of course we really need to spend a full night or two doing the tedious task of drift alignment so that our autoguider won't have to work as hard and that autoguiding will work across the entire sky, all in all though we have made some great progress over the last few weeks so it's just a matter of building upon these successes.

Posted by Jonathan Green

Friday, April 28, 2017

Autoguiding and Remote Control

After a beautifully clear day, and with the successes of the night before still fresh in our minds, Jonathan headed out to the observatory for sundown hoping to get an early start on some more work getting all the equipment set up.  Unfortunately the weather seemed to have other plans, and in not long at all, the sky was covered in cloud.

So after it started to look pretty hopeless, he closed up again and headed off.

After being busy with other things earlier in the evening, I became free at around 10pm and seeing the skies reasonably clear at home in Swanson, headed out - expecting Jonathan to perhaps still be around.  He wasn't of course after closing up earlier - but with only  a few clouds on the horizon, I set about a few tasks.

Whilst polar alignment still needs some refinement, I was also keen to get the autoguiding working again.  Even though we have guider relays on the ST-10XME camera,we are using "DirectGuide" (the SoftwareBisque implementation of pulse guiding) which is more accurate and required less cables.

Since we're using Maxim DL for the imaging, then Maxim needs to control the mount - this is done via TheSkyX's ASCOM driver.  This provides ASCOM with what looks like a telescope mount, with multiple autoguider options - including DirectGuide.  This was quickly set up and moving the manual controls in Maxim confirmed that the guider inputs weew working as expected.

NGC4038/NGC4039  20min (10x 120s) Stack
The guider calibrated correctly and seemed to be working, so I did a quick focus run and set up a short run of 120 second images of the NGC4038/NGC4039 Antennae galaxies (just in luminance) .  I did forget to turn temperature compensation back on though so my focus drifted a little between the images.

Whilst the image run was going on, I tool the opportunity to configure the PCs (the one in the dome and the one in the bunkroom) to be able to talk to each other - since we still have no internet connection at this point (we're working on that) - it was just a simple matter of assigning a fixed internal IP address on each machine.

NGC4945 28min (14x120s) Stack
This allowed us to use Remote Desktop to control the dome computer from the relative warmth and light of the bunkroom.  Jonathan arrived from being clouded out at an attempt at some photography further north to find that Kumeu was now perfectly clear.

Jonathan continued imaging for a while taking a (much better!!) set of images of NGC4945 - he of course noticed the focuser issue and came out with a very nice image!

Overall I'm really pleased with our progress this week getting things back into an operational state.  The polar alignment needs more work - though with Autoguiding working now we can still image whilst we refine that fully.  We have identified we need to work on collimation - so getting CCDInspector up and running for that is on the list.

The next big job is slaving the dome - we had some issues with the sensor wheel slipping resulting in us getting inconsistent counts.  This caused problems that the dome and the scope did not stay synced after a short run - we need to revisit this - perhaps install a rubber o ring or band "tyre" on the wheel - which may need a groove for it to sit in.

Steve


Wednesday, April 26, 2017

Back In Action!

After almost a year of the observatory being on hiatus, we finally got the observatory up and running again, the Paramount GT-1100S unfortunately could only be repaired by upgrading it's internal motherboard and chip sets to that of the Paramount ME-II, thankfully Software Bisque provided us with an upgrade kit for a reasonable price, the upgrade required us to modify the mount itself to accommodate for the larger chipsets and motherboard, the work was mainly carried out by Steve Hennerley and Tony Burns, after many setbacks and delays the mount is now operational ( expect a much more detailed account of the upgrade from Steve in the future ), Jonathan Green and Grant Christie then installed the newly upgraded mount back on the pier after cyclone cook bypassed Auckland the other week.


The upgraded Paramount GT-1100S
Last night Jonathan Green and Steve Hennerley met out at Kumeu to cable up the mount and give it a test run, we quickly ran into problems after connecting the mount to the Sky X as we found that it was tracking in the wrong direction in the right ascension drive, getting a bit frustrated with not being able to fix the problem in the Sky X we decided to install the latest version of the "Sky" from the Software Bisque website as our old version was well out of date, this completely fixed our problem with the right ascension drive, so once that was sorted we moved onto drift aligning the telescope after re-setting the altitude graduation of the mount to the latitude of our location we were pleased to see we weren't really that far off polar alignment, we spent maybe around two hours or so drift aligning but plan to do a much more thorough job once we refine the balance of the optical tube, camera and counterweights.


After getting a rough polar alignment we set about focusing the telescope, we quickly became frustrated with the auto-focus failing, so after re-setting the temperature compensating focuser to the halfway position, Steve manually focused the telescope and then locked the primary mirror using the shipping bolts, we still couldn't get an auto focus after doing that but we decided the focus was probably good enough to move forward, so we then set about finding a star to synchronize onto so that way the "Sky X" would know where the telescope was pointing, obviously the new version of the Sky X is a bit different than the old version that we were used to using, so it took us a while to figure out how to do it, what we actually ended up doing was loading up an old pointing model I captured before all the troubles began and then re-calibrated the model by syncing to the star Spica, this seemed to work well with targets being only slightly off center, we didn't worry about that too much as the camera will need to come off the mount to have the filters looked at and we will also need to re-balance and re-collimate the "Nustrini" optical tube, so once that's all done we will no doubt attempt a really robust pointing model that should increase our accuracy exponentially.
Steve Hennerley cabling up the upgraded mount at Kumeu Observatory last night

By this time it was starting to get late and Steve had to work in the morning so we got onto doing what more we could before Steve had to go, so we ended up getting Pin Point in MaxIm DL to successfully plate solve an image and we also got Image Link in the Sky X to successfully plate solve an image which will be very helpful once we get back to starting a new pointing model, Steve also wanted to capture a "first light" image and did so by capturing the Sombrero galaxy, after Steve left I couldn't help myself and set about capturing ten one minute images of Messier 83 (Southern Pinwheel Galaxy) I then calibrated them using my old calibration files ( so they probably didn't work that effectively, although visually you could see a big improvement in the images once they were calibrated ) then stacked the images to produce the best "first light" image I could, the result is below, although please note the focus was still only manually done at this point.

Messier 83 (Southern Pinwheel Galaxy)

After completing the "first light" image, I set about trying to figure out why the auto focus wasn't working, I must admit to being a little rusty after being out of action for so long but after many frustrating auto-focus fails I managed to find the correct settings in the options to make it work and managed to focus a star at a FWHM of 2.5 arcseconds per pixel, which isn't fantastic but is probably more indicative of our collimation rather than the local "seeing" conditions, Steve had fixed the temperature probe at the start of the night and after setting the focuser to track the temperature I can confirm that the TCF was successfully tracking the temperature changes for the rest of the night, I did then attempt a small pointing model but that ended up failing as the sample points were not solving in Image Link, it must have been another setting that needs adjustment or maybe the focus wasn't good enough, I'm not sure, at this stage it was getting pretty late ( 3:45 am ) so I packed down and closed up the dome and headed home around ( 4 am ).

All in all it was a good start, we still have loads of work ahead of us but hopefully we can now move forward confident that the upgraded mount will be dependable, I'm also looking forward to getting back out there tonight if the sky stays clear as well.

Posted by Jonathan Green

Sunday, June 26, 2016

Investigation

After the highs and lows of last week, it was time to start the investigation into whether or not we can get the Paramount back into operation.  During the week we had done a lot of reading and research - slightly worryingly SoftwareBisque - the manufacturer of the mount had informed us that it would be unusual for a firmware glitch to cause failure of the serial communication.

Testing the serial line
We started by checking the serial connection - we had borrowed a serial tester from Tim Natusch - and connected it inline.  We had hoped to see DSR (Data Set Ready) and CTS (Clear To Send) lights - indicating that the mount was ready to communicate.  We didn't - however this didn't upset us too much as many devices don't bother with these connections and use a basic "3-wire" protocol (Rx,Tx,GND).

Next step was the SoftwareBisque MKSER utility - still no internet at the dome, but we brought it along on a USB stick.  Quite typically (remember Murphy - he's never far away) - trying to run the software gave us a "DLL Not Found" error.

As Tony, Jonathan and I "fondly" recalled stories of "DLL Hell", I tethered my Macbook to my phone and set about finding the offending DLL files and transferred them to the Dome PC.

Once up and running (and after I'd worked out how to switch the active COM port in the utility) I quickly discovered the mount in fact DID seem to be communicating - though only the DEC board, not the RA.  After a restart of the mount, we could see that both boards were communicating, and we could even initiate a "home" in both axes through the software.

This was indeed excellent news - as it meant that the basic underlying serial communication to the control boards was working, and the control boards were able to drive their respective mount axes.  As a test, I disconnected MKSER (whilst it was working) and started up TS6.  TS6 failed to connect - and then I discovered that the MKSER utility was now unable to communicate too.  A restart of the mount brought it up again, and I also proved that TSX caused the same issue as well.
Inside the Paramount GT-1100S

Since I also had a copy of the firmware for the mount, we had decided that reloading the firmware was a sensible option.  From the research we had done we knew we had to set a DIP switch on the control boards to PGM (Program). Whilst I was doing the tests above, Tony set to the mount with a hex key or two to removed the side plate covering the mount innards.

After carefully levering off the side of the mount it was easy to see the three internal boards and all the cabling.  We were quite encouraged that there didn't seem to be too much dust, dirt or insect activity in there.  It wasn't immediately obvious though where the programming switch would be - and the boards were certainly not all that easy to get to.

Now where is this DIP switch?
 Eventually though we did locate the correct switch which was on the right-hand board, mad a little harder to see clearly due to the OTA being on that side of the mount in its home position (as you can see in the photo of me peering in there with a torch)

The sporadic rain showers of the day didn't really help as we couldn't really have the dome shutter open most of the time to help with getting some light on the subject - good job we had plenty of torches!

DIP switch located, we set it into PGM mode, told the software where to find the file and hit the "download" button to reprogram (and hopefully re-initialise) the RA board.

Those of you playing along will immediately realise that good old Murph' wasn't gonna let us off that easy.

"Error 1008"

Hmm.  Let's check the firmware.  We were uploading 1.1.45 (same as the previous version).
"Version 1.0.2"

Bugger.  What now!? Back to the laptop and the SB support forums - it turns out that whilst the version of MKSER we have specifically says it supports the GT-1100S - it doesn't actually support uploading to the MKS3000 and an older version is needed.  Naturally that version is not available for download.

Long story short (well short-er!) - without the earlier version of MKSER, we're stuck -I've emailed and forum posted to SB to try and get a copy, and Grant C is going to check his old hard drives from back then to see if he might have a copy from 2002 when the firmware was last updated.

Scariest part was realising that with the mount in a state without the correct firmware loaded on one of the boards, we had to power off (and disconnect).  I was a little worried we might not get connected again.  Biting the bullet we powered off, reset the controller to RUN and powered back on.

RA Board didn't connect.

Mount would not joystick or home in RA.

Rather than panic (or cry - either of which would have been perfectly reasonable at this point!) I powered off and switched back to PGM.  Communication established again to the RA board (but still reporting 1.0.2).  Looks like we *really* need that older MKSER.

With nothing further we could really do with the mount at this stage, we replaced the cover (can't have the spiders finding a new place to set up home) and powered down.  Hopefully we can get the software soon.

Keeping the cables under control.
With no more mount stuff to do I decided to check a fault that Jonathan had reported with our new dehumidifier - it had stopped going and was showing an error. Turns out the "error" was "tF" and it meant "tank full" and indeed the water tank was full - meaning the permanent drain wasn't draining. Turns out that as well as a screw fitting cap, there was a rubber bung I'd failed to remove as well!

Finally, Jonathan had purchased a couple of surge protected power boards the week before.  Since we'd had a few power outages and electrical storms over the past couple of weeks, it seemed like the sensible thing to do would be to make sure that a power surge didn't end up as the next drama down on the list.

I took the opportunity to tidy the cables around the pier a little more by mounting the new power board and all the associated power supplies on a board bolted to the pier.  Much tidier and off the floor, this arrangement will also mean that the equipment will be a little more protected in the event we get a leak in the dome. As a bonus, the new boards have also got USB charger sockets - must add microUSB and lightning charger leads to the list to so that we can keep our phones topped up whilst working out there.

Steve

Monday, June 20, 2016

Murphy Strikes Back

Anyone who has heard me talking about Kumeu Observatory recently will be familiar with the concept of how Murphy's law operates at full strength in Astronomy - and in particular - with our work out at Kumeu.

After a really positive and productive evening a few nights previous, Jonathan, Tony and I spent an initially productive and hopeful time out at Kumeu during the day on Sunday which ended with a new major issue for us to address.

On the productive side, we manage to install the new dehumidifier that we had purchased.  The model we bought is compact and wall mounted so it keeps out of the way.  We managed to find a perfect location for it inside the dome in a position that allowed us to pass the drain hose through the wall (after a quick trip to Mitre10 for drill bits and silicone) and directly into a drainpipe.  The dehumidifier is set to target a particular humidity level (so it's not running all the time) - we've set this to 70% for now and we'll adjust as necessary to keep it dry without consuming too much power.

We set about more investigations of the Zone of Death issue - First step was an update of TheSkyX (TSX) to the latest version (which made no difference) - so we carried on - particularly wanting to confirm or deny the possibility of the previously broken cables being the source of the error (the hypothesis was that at certain mount positions we may be extending the cables for one of the encoders).  With the covers off we could see a few important points,

  1. No movement of the mount seemed to be overextending any cables
  2. Tracing the set of cables that got damaged, it as clear that all the cores on the multicore ribbon cable/connector (except 4) were used for the "passthrough" cabling (power, serial and parallel connectors), and not for any mount control.  The 4 cores that were in use were for the home position sensor (working fine) and the motor, encoders etc were on seperate cables that were not damaged.
  3. For the future, it was noted that most of the cable bundle was completely unused - so if we ever do have to pull the mount apart in future, we should probably remove it all and replace with modern power and USB
Confident that a physical cable issue was almost certainly not the cause of the ZoD we set about running more tests.
  • The ZoD covers an area around the South/SouthEast in the sky
  • We could always slew accurately to any location within the ZoD without issue
  • Once in the ZoD, we can use the joystick and accurately navigate the scope around the ZoD and the mount continues to accurately track position back to the computer.
  • If we joystick out of the ZoD, we can slew to a new position (in or out of the ZoD) no problem
  • If we try to slew from the computer at all (even a 1 arcsecond "jog") we see the following
    • Mount does a slow move in RA - much more than it should
    • at the end of this, the reported position back to the computer is send back - radically different to what it should be, this puts the mount completely out of sync
    • The mount then "continues" the slew into an incorrect position 
  • From here, the mount will now slew anywhere in the sky - apparently "accurately" but completely out of sync (so not the same part of the sky the computer thinks it should be) - including into and out of the ZoD
  • The new incorrect position appears to be largely out in RA and out to a lesser degree in DEC
This behaviour led us to think that, as we were starting to consider the other night, that software might be an issue - Either TheSkyX (still, even though we had updated it) or the firmware on the mount itself.

Then we had (what we though was) a major breakthrough - we tried TheSky6.  And it worked. No ZoD issues at all !!!.  When we switched back to TSX the ZoD returned.  We were very hopeful that the whole thing was just a software glitch on the PC.  We set about completely removing and reinstalling TSX from scratch.

When we had done this, very hopefully, we tried again.  This time, the behaviour was not quite the same - there was no longer any random slews from within the ZoD.  Yay.!!!!  However, there was actually no slewing AT ALL once we entered the ZoD - Boooooo!!!   We could still joystick (and issue move commands from TSX) but no slewing to a target. 

Clearly something in the communication between TSX and the mount had to be at fault.but what? and what was different in the reinstalled version that made the behaviour different?

Checking through the mount configuration in the "BisqueTCS" panel, the only obvious thing was that the mount was apparently reporting that the "Hemisphere Setup" was set to "not configured".  Knowing we'd previously selected "Southern" (of course) when we initially set up TSX for this mount, I clicked this option.  The mount disconnected (as expected) and then the TSX software froze up and then crashed.  After reloading the mount was connecting ok, but seemed not to be quite functioning correctly - for some reason the joystick was only allowing the mount to slew in DEC. 

Thinking the hemisphere setup routine had not completed, I tried again (though selecting Northern Hemisphere to ensure it changed).  This worked properly - the mount disconnected, then connected again and it seemed to clear the issue up.  Of course I then needed to ensure we went back to "southern hemisphere" mode, so I again selected this option. 

The mount disconnected, and reconnected - but would not respond correctly to a "home" command, giving an error that the motors we currently operational.  We restarted everything - but this time the mount would not reconnect to serial control. The mysterious issue where the mount would not joystick in RA was also back.  The mount did respond to a "home" command (double click of the joystick) though - proving both axes were still controlable. 

After another full power off restart of everything (this is my IT support background kicking in) we learned that sometimes, after a power cycle and the initial "home" command, the mount would start and the RA would work and the DEC not from the joystick.  Sometimes it was the other way round.  Sometimes both both work.  Unfortunately serial communication doesn't seem to be working at all now.......   We tested the serial port, and switched ports with the Optec TCF to make sure the PC hadn't locked out the COM port for some reason. No Joy. 

Frustrated and annoyed we shut everything down and went home.  Next steps is to attempt to recover from this situation.  There is a utility that permits a lower level communication with the internal control board that we can try - possibly to reload the firmware.  There are also, I believe, further options for programming the control board (the MKS3000) directly - so we've not lost all hope!

That said, we really are starting to tire of Murphy's Law of Astronomy - it seems that just as we are getting some serious leaps forwards-  we get our biggest setbacks.... 

Steve




Friday, June 17, 2016

A Productive Night

Last night Steve Hennerley and myself meet up at Kumeu Observatory, it ended up being a very productive night, we did some tests on the "Zone of Death" and our current theory is that it's not a hardware issue but has something to do with the Sky X, Steve noted that our version of the Sky X was out of date so maybe by reinstalling the latest version of the Sky we might be able to resolve the issue, the evidence for the Sky X being the problem has been mounting with the Sky X randomly losing synchronisation and the home position, also slewing through the "Zone of Death" with the joystick has no adverse affect and there has been some weird flipping of the way the Sky X displays the sky when zooming in on a targets lately as well.

One of the first things we did was calculate the focal length of the telescope, Grant Christie had suggested we fill in all the configurations in MaxIm DL so that they will get picked up by the fits header after I had sent him some test microlensing images the other day, so after a bit of calculating we entered the focal length and aperture of the telescope and the latitude and longitude of the Kumeu Observatory site, the only thing we didn't enter was the % of the central obstruction, Steve said he would bring out his digital calipers next time so we can measure it accurately.

With the sky being so clear last night we decided to have a go at collimating the telescope, the telescopes collimation has degraded recently probably from all the times we have had to take the OTA off the mount, so it was good to see that it was not the "astronomical seeing" that was causing the bad focus results I've been getting recently, after spending a bit of time getting the collimation refined using the open star cluster method and then some single semi bright stars, Steve noted that we had got the collimation as good as we could using the methods that we had at our disposal but that we could improve the collimation even more using a program like CCD Inspector, we would have downloaded it and installed it on the night but the internet is still not working out at Kumeu Observatory so that's another issue that still needs to be resolved, after doing as good a job as possible refining the collimation we could see a definite improvement in the auto focus results.

The next thing we got onto was getting the Pin Point Astrometry to work in MaxIm DL, after Steve got that working I was delighted to see that we can now use the "point telescope here" function in MaxIm DL, this is a really helpful option when wanting to center an object in an image in MaxIm DL so you don't have to waste time jogging the telescope.

After that we got onto trying to get the internal Auto-guider of the SBIG ST-10 XME to work, after a bit of investigating Steve managed to get the Auto-guider working, this is a huge step forward for us because we are now not limited to 100 - 200 second exposures, after Steve went home around 2:30 am I took some test images, the stars looked nice and round in both 5 minute and 10 minute exposures, needless to say I was very happy with the results.

All this fantastic progress was tempered by the discovery that we have mold growing on the inside of the corrector plate as well as on the primary mirror so we are going to have to take apart the OTA to be able to clean the telescope up, Steve suggested we might even want to try get the primary mirror re-aluminized while we have the OTA apart, we could even look to flock the interior of the optical tube seeing as we will have access to the interior of the tube, the outside of the corrector plate also needs a good clean as well.

We did notice a fair bit of condensation in the dome over the night so we plan to get out to Kumeu over the weekend and get the recently purchased dehumidifier installed to deal with this problem, I have also purchased two surge protectors so we can protect all the equipment from any electrical faults as well, as we have had a fair amount of power cuts out at the observatory over the past few months as well.

Also when I was shutting down the dome at 5 am, I put the telescope back to the home position to find that the Sky X had again lost it's home position, the telescope was in the home position but as far as the Sky X was concerned the home position was up near the zenith! I have no idea why the Sky X is randomly losing it's synchronisation but this is further evidence that perhaps we do have a problem with the software, it might be solved by simply updating the Sky X to the latest version or maybe we will have to reinstall the drivers I'm not sure, so even though we still have a few issues to work through I went home very satisfied that we had made some fantastic progress.


Ten minute auto-guided test exposure of the Eagle Nebula, the brighter stars all showed signs of bleeding as you would expect from such a long exposure but I was really happy to see the stars stay so spherical over such a long time. ^

Posted by Jonathan Green

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