Mike Lewis
Staff Member
So in spite of pulling the plug on my trip to AZ due to coronavirus concerns, with my friend's generous help I have been able to have my gear set up and do some checkout and even a little imaging. The weather has been usable most of the nights, and now that my gear is assembled, I could potentially have a few more nights of opportunities before he packs stuff up to store in AZ and heads back to CO.
Here is what the setup looks like. Mine is the smaller mount/scope in the background. :
We are setup on carefully aligned piers that are not physically mounted in the ground but secured with heavy sandbags. A compromise over a true observatory setup, but better than setup/teardown every night. Once aligned, the critical gear can be removed and re-installed and if done with some care, the sky alignment is not disturbed. With the powerful TPoint software in TheSkyX, I get sub 50 arcsec pointing all over the sky, and can also use a closed loop slew to even more accurately point to any object, visible or not.
My gear was set up Monday, and so far I have had portions of 2 nights to work with it. Here are the takeaways:
1) The remote link has been reliable, other than some self induced issues when Matthew and I were trying to 'redesign' things to maximize the outgoing data rates. The 1MBit uplink rate has been somewhat problematic, and would be a complete non-starter if there were any other users using uplink bandwidth (either locally at my friend's house of elsewhere remotely.) This was something we were not able to really evaluate prior to getting set up though, and is not a totally unexpected result. There are some options to increase the rate for more expenditure per month - we will likely talk through that after the fact.
2) The integration of the On Axis Guider (ONAG) has predictably been a somewhat slow and complex process, but I have managed to make some progress. This is a cool device that allows you to guide with your main scope, using the primary light path, giving you a full frame available to both the guide camera and the imaging camera by using a dichroic beam splitter (i.e. cold mirror.) With this set up properly, I can guide on the full scene (not using stars but using image analysis of the full frame to indicate drift) and also if both cameras are parfocal (i.e. focusing at the same place on the scope focuser) I can then autofocus in real-time, while imaging, using the full scene, without having to slew off to another temporary targeted star to periodically check focus that way. Super advantageous, but a bit tricky to integrate, especially without being there. I can pass on some links and/or additional info for anyone interested.
3) ONAG guider focus is not fully parfocal yet, but I think that with perhaps one more session outside and my friend manning the helical focuser this could get dialed in. This has been a little strange though, as previous adjustments have resulted in what looked like an improvement only to be followed by unstable readings.
4) The main scope autofocuser from Optec continues to work well, and when paired with @focus3 inside of TheSkyX is giving results that seem to be equivalent to the Bahtinov method which is very nice. The SVQ100 also seem to be very stable focus-wise, having come up last night still in perfect focus. I did have some focus drift with temperature over the evening I think that I did eventually detect and fix. This is the type of thing I hope to eliminate when/if I can get the system parfocal between the 2 cameras and use the ONAG autofocus software.
5) I am running a 50 point T-Point model and in general doing fine. Pointing is spot on, but tracking has not been quite what I have wanted, The guider astigmatism is a 'feature' for the ONAG software, allowing it to autofocus in real-time, but with the coarse guider focus still not quite dialed in, the resulting lozenge shaped stars are not compatible with either PHD2 or TheSkyX guiding algorithms. Monday night I was able to make no progress with the ONAG software due to a config problem, so was unguided. I shot a couple of 5 minute unguided exposures and was not really happy with the results. Tuesday night I did get at least the ONAG full sky autoguiding online for a couple of periods during the night. The combo of ONAG guiding and reducing my exposure lengths to 3 minutes (and turning up the camera gain) seemed to work pretty well, and brought my star eccentricity down a bit, although not perfect. One VERY interesting thing I noticed right at the end of the night was that according to the detailed plots on guider performance supplied by the ONAG software, I was able to notice that my guiding in the X direction was actually INCREASING my tracking error. Sure enough, when I turned off guiding in the X direction I could see my percent guiding error in the X axis start to decrease. The software is able to plot this because it keeps a separate record of both what the guided tracking accuracy is, and also what the unguided tracking accuracy would have been if no corrections had been applied. Kinda neat, and now a quantitative way to see when one is 'over-guiding' their mount, something I have suspected I was having issues with multiple times in the past.
6) So with all that said, I took some data on the Jellyfish Nebula. Throwing out any test frames, frames not well centered on the object, and other unusable data, I think I may have somewhere between 2 and 3 hours of narrowband captures on the object. We will see how the star shapes, signal levels, noise, and focus end up looking once the data is back here but potentially an image to come out of that I am hoping. A very cool object I have liked since seeing my other friend Dan's great results, and it was fun to see the OIII and SII signal levels swapped from what I am used to, with OIII not very prevalent and SII really showing up. I have no efficient way to get data back over such a slow link so will have to wait to get this and any other data I might be able to capture until my friend returns at the end of this month.
So that's about it. With rain in the forecast last night it was time to catch up on other family responsibilities and sleep, but if the forecast in AZ for tonight holds then hopefully some more progress and more data before my friend is heading back at the end of the month.
If I operate the system tonight there will be something very fun about operating gear and shooting sky images when there is snow falling right outside my window here in CO
ML
Here is what the setup looks like. Mine is the smaller mount/scope in the background. :
We are setup on carefully aligned piers that are not physically mounted in the ground but secured with heavy sandbags. A compromise over a true observatory setup, but better than setup/teardown every night. Once aligned, the critical gear can be removed and re-installed and if done with some care, the sky alignment is not disturbed. With the powerful TPoint software in TheSkyX, I get sub 50 arcsec pointing all over the sky, and can also use a closed loop slew to even more accurately point to any object, visible or not.
My gear was set up Monday, and so far I have had portions of 2 nights to work with it. Here are the takeaways:
1) The remote link has been reliable, other than some self induced issues when Matthew and I were trying to 'redesign' things to maximize the outgoing data rates. The 1MBit uplink rate has been somewhat problematic, and would be a complete non-starter if there were any other users using uplink bandwidth (either locally at my friend's house of elsewhere remotely.) This was something we were not able to really evaluate prior to getting set up though, and is not a totally unexpected result. There are some options to increase the rate for more expenditure per month - we will likely talk through that after the fact.
2) The integration of the On Axis Guider (ONAG) has predictably been a somewhat slow and complex process, but I have managed to make some progress. This is a cool device that allows you to guide with your main scope, using the primary light path, giving you a full frame available to both the guide camera and the imaging camera by using a dichroic beam splitter (i.e. cold mirror.) With this set up properly, I can guide on the full scene (not using stars but using image analysis of the full frame to indicate drift) and also if both cameras are parfocal (i.e. focusing at the same place on the scope focuser) I can then autofocus in real-time, while imaging, using the full scene, without having to slew off to another temporary targeted star to periodically check focus that way. Super advantageous, but a bit tricky to integrate, especially without being there. I can pass on some links and/or additional info for anyone interested.
3) ONAG guider focus is not fully parfocal yet, but I think that with perhaps one more session outside and my friend manning the helical focuser this could get dialed in. This has been a little strange though, as previous adjustments have resulted in what looked like an improvement only to be followed by unstable readings.
4) The main scope autofocuser from Optec continues to work well, and when paired with @focus3 inside of TheSkyX is giving results that seem to be equivalent to the Bahtinov method which is very nice. The SVQ100 also seem to be very stable focus-wise, having come up last night still in perfect focus. I did have some focus drift with temperature over the evening I think that I did eventually detect and fix. This is the type of thing I hope to eliminate when/if I can get the system parfocal between the 2 cameras and use the ONAG autofocus software.
5) I am running a 50 point T-Point model and in general doing fine. Pointing is spot on, but tracking has not been quite what I have wanted, The guider astigmatism is a 'feature' for the ONAG software, allowing it to autofocus in real-time, but with the coarse guider focus still not quite dialed in, the resulting lozenge shaped stars are not compatible with either PHD2 or TheSkyX guiding algorithms. Monday night I was able to make no progress with the ONAG software due to a config problem, so was unguided. I shot a couple of 5 minute unguided exposures and was not really happy with the results. Tuesday night I did get at least the ONAG full sky autoguiding online for a couple of periods during the night. The combo of ONAG guiding and reducing my exposure lengths to 3 minutes (and turning up the camera gain) seemed to work pretty well, and brought my star eccentricity down a bit, although not perfect. One VERY interesting thing I noticed right at the end of the night was that according to the detailed plots on guider performance supplied by the ONAG software, I was able to notice that my guiding in the X direction was actually INCREASING my tracking error. Sure enough, when I turned off guiding in the X direction I could see my percent guiding error in the X axis start to decrease. The software is able to plot this because it keeps a separate record of both what the guided tracking accuracy is, and also what the unguided tracking accuracy would have been if no corrections had been applied. Kinda neat, and now a quantitative way to see when one is 'over-guiding' their mount, something I have suspected I was having issues with multiple times in the past.
6) So with all that said, I took some data on the Jellyfish Nebula. Throwing out any test frames, frames not well centered on the object, and other unusable data, I think I may have somewhere between 2 and 3 hours of narrowband captures on the object. We will see how the star shapes, signal levels, noise, and focus end up looking once the data is back here but potentially an image to come out of that I am hoping. A very cool object I have liked since seeing my other friend Dan's great results, and it was fun to see the OIII and SII signal levels swapped from what I am used to, with OIII not very prevalent and SII really showing up. I have no efficient way to get data back over such a slow link so will have to wait to get this and any other data I might be able to capture until my friend returns at the end of this month.
So that's about it. With rain in the forecast last night it was time to catch up on other family responsibilities and sleep, but if the forecast in AZ for tonight holds then hopefully some more progress and more data before my friend is heading back at the end of the month.
If I operate the system tonight there will be something very fun about operating gear and shooting sky images when there is snow falling right outside my window here in CO
ML