Automatic Observations - Prospective user of Advanced version

Hardware and software setups, autoguiding and plate solving parameters, etc..
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rbotero
Posts: 1
Joined: Thu Jan 04, 2018 6:51 am

Thu Jan 04, 2018 8:38 am

Hi Hamza

I halfway through my 80-day trial of Prism Advanced and wanted to check a few points – particularly on automation – before considering buying the full licence.

Firstly, my main reason to look at Prism is consolidation of all my automatic observation needs under a single piece of software that is stable and is kept up-to-date. In that regard, I think Prism looks like a prime candidate. I know it has been around for over a decade, it is well supported and continuously developed by Cyril Cavadore and you have taken up the baton from Bob Sandness successfully.

Secondly, I currently use a set of programmes successfully, but some are becoming outdated and the investment in new licences would almost equal the cost of acquiring Prism’s.

All my equipment is housed in a RoR in my backyard, but it is managed as if it was completely remote. I don’t even keep a computer in the RoR and all devices are controlled from a PC inside through LAN. Equipment is monitored with an iPCam and switched on and off through an iPSwitch from DigiLoggers. All drivers are ASCOM compliant.

As mentioned earlier, my main interest in Prism centres around its automation abilities. I will only be acquiring the images through Prism to be processed elsewhere. At the moment my targets are all “pretty pictures” rather than any sort of more serious scientific interest/research. My main objectives would be for Prism to:

I. Control acquisition process from beginning of session to end
a. Getting equipment ready (connecting, cooling, focusing)
b. Opening/closing dome; monitoring weather
c. Alerting me in case of session suspension, finish, errors
II. Help plan observation sessions
a. By using its skychart and any scheduling features it may have

After testing the software for some days now, I have the following specific questions:

1. Can Prism control an iPCam’s IR light so that it switches off during acquisition yet switches on whilst the scope slews or my observatory closes?
2. In Automatic Observations, can list of objects be updated (i.e. change order of filters, number of images, etc) on the run whilst the process is running? I think not but this would be a very useful feature in variable weather which I suffer from in the UK
3. In addition to the above, can I set time limits for when a target should end and another start? This links to my horizon limits as per 6 below
4. In Automatic Observations, or Focusing in general, can Prism start a session by choosing a star near the meridian to focus on rather than a star near the initial target? Sometimes the initial target can be more than 30d away from the meridian and the focus on target seems to only be able to slew 9d from current target
5. Moreover, Prism presently compares focusing near target results versus a current image focus. This assumes the telescope is roughly focused before start. This may not be the case for example if starting a new session after a few days of inactivity and not having manually focused before an automatic session
6. Meridian flip, can Prism allow my mount driver to control meridian limits? I use an Astro-Physics mount which happily images with counterweights up and APCC which controls my meridian limits. This in part applies to my horizon limits and the zones that need to excluded because of trees, roofs, etc
o More precisely, can Prism read off time to meridian from the driver so that it adjusts dynamically depending on APCC’s data? (Delay to and from meridian is non-existent with APCC and can be negative): APCC stores profiles for meridian and horizon limits – both specific to my observatory and different limits depending on object’s elevation
7. Does Prism support Good Night Sleep (GNS) from Lunatico Astronomia (which is presently supported by other automation software)? I would like to keep a way of real time monitoring which wakes me up when there are issues I can fix on the go. This links to 2 above

On a more general note, I think I have found a couple of bugs:

- In the latest version of Prism (which I got from the update option under help), the Switches control does not work with the current ASCOM driver for Digital Loggers. I can confirm it worked previously (in the version I downloaded from your webpage).
- If I STOP an automatic observation session and restart it (because of an issue or because I want to change my list/parameters as per 2 above), Prism seems to go into a never-ending cooling loop (as the CCD camera was already cold) and does not restart immediately. It seems to try to match the imaging temperature too closely and sends my peltier into overdrive. For reference, I use a Moravian G4-16000 camera and have the latest ASCOM drivers

Happy to take this offline/by phone if too specific for the forum.
Thanks

Roberto
Hamza Touhami
Site Admin
Posts: 564
Joined: Sat May 20, 2017 6:05 pm
Location: Phoenix,AZ
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Fri Jan 05, 2018 8:53 am

Good morning Mr. Botero,

Thanks for the excellent post and I will try and answer below your questions:
1. Can Prism control an iPCam’s IR light so that it switches off during acquisition yet switches on whilst the scope slews or my observatory closes?
Answer: No, not at this time. At my own remote observatory, I do not use the IR light during automation because the IR light actually floods some optical sensors like my dome controller. But no, PRISM does not control IR cameras.
2. In Automatic Observations, can list of objects be updated (i.e. change order of filters, number of images, etc) on the run whilst the process is running? I think not but this would be a very useful feature in variable weather which I suffer from in the UK
Answer: Not at this since time since automation in PRISM was designed with a fire-and-forget philosophy. One could always cancel the run and amend the settings and/or targets if they wish.
3. In addition to the above, can I set time limits for when a target should end and another start? This links to my horizon limits as per 6 below
Answer: setting times per target no but you can do this with other means such as: Hour angle limits, minimum altitude limits, etc..
4. In Automatic Observations, or Focusing in general, can Prism start a session by choosing a star near the meridian to focus on rather than a star near the initial target? Sometimes the initial target can be more than 30d away from the meridian and the focus on target seems to only be able to slew 9d from current target
Answer: No and by design. Since PRISM is designed to work with everyone's equipment, people with moving primary mirrors and less than ideal OTA stiffness will suffer greatly from the movement. I am not saying this option cannot be added later either :D
5. Moreover, Prism presently compares focusing near target results versus a current image focus. This assumes the telescope is roughly focused before start. This may not be the case for example if starting a new session after a few days of inactivity and not having manually focused before an automatic session.
Answer: Well for a mobile setup, I completely understand. My own permanent observatory autofocuses night after night without issue. Moreover, I had a month of inactivity and focus remained between the range I set. However, I can see this being a problem if someone does not choose the right "focus span" where they either have a narrow window of focus or too few steps. I am working on an automatic observation tutorial video to explain all of this functions.
6. Meridian flip, can Prism allow my mount driver to control meridian limits? I use an Astro-Physics mount which happily images with counterweights up and APCC which controls my meridian limits. This in part applies to my horizon limits and the zones that need to excluded because of trees, roofs, etc
o More precisely, can Prism read off time to meridian from the driver so that it adjusts dynamically depending on APCC’s data? (Delay to and from meridian is non-existent with APCC and can be negative): APCC stores profiles for meridian and horizon limits – both specific to my observatory and different limits depending on object’s elevation

Answer: This is a really tricky one. APCC and all its functions is transparent since PRISM sees it as any other driver. PRISM does not control your meridian flip but "causes" it to happen. Example: if you set your meridian limit in APCC as the meridian ( or 0) then you just tell PRISM to stop imaging 5 minutes before the limit and go and wait 5 minutes after the meridian. Since APCC is set to flip at the meridian (or 0), by PRISM telling APCC to go to +5 after the meridian, this will cause a meridian flip.
7. Does Prism support Good Night Sleep (GNS) from Lunatico Astronomia (which is presently supported by other automation software)? I would like to keep a way of real time monitoring which wakes me up when there are issues I can fix on the go. This links to 2 above
Answer: Not at this time, PRISM includes safeguards in place to ensure your system is protected against changing weather. My own system in NM does this by closing the shutter of the dome, parking the mount and keeping everything online. PRISM will then check the weather every 60 seconds to make decisions if it can resume. If the conditions get better, then it will resume imaging like nothing happened. If not, It will execute your shutdown procedure. The short answer to supporting the GNS system, not at this time.
Hamza Touhami | Site Administrator
Hyperion-Astronomy.com
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