VPhot and its Future

Affiliation
American Association of Variable Star Observers (AAVSO)
Tue, 07/09/2013 - 06:03

 

Here are some observations regarding VPhot:

On the positive side:

1. In general, I find it very easy / friendly to use.

2. Providing VPhot from the cloud is definitely a step in the right direction - it also sidesteps the whole Windows versus Mac debate, when it comes to PC-resident software.

3. I would like to continue to use it.

However,

  1. The documentation is poor: The tutorials are (and are acknowledged by the AAVSO to be) out-of-date, and no downloadable .pdf or other documentation is available that describes either: (a) the internal workings of VPhot; and (b) How to use VPhot.  Both are needed.
  2. From reading various forums, it would appear that both updated tutorials and a manual have been promised for quite a long time. However, nothing has eventuated on either front.
  3. From a long career in software development, I am aware that software without adequate documentation is very poor software indeed. But the thinking (at least in amateur or semi-amateur circles) appears to be that producing the code to do certain things (measure stellar magnitudes, for example) is all that really matters and it is OK that the would-be user simply muddles through without documentation.
  4. At least in one forum, the AAVSO has stated that it is committed to VPhot “as a flagship offering” to members. However, that claim does not sit well with the lack of support (tutorials and documentation) provided by the AAVSO for VPhot.

As the AAVSO does not appear to be devoting any resources to addressing the above deficiencies, I am wondering whether VPhot is simply a “dead duck”.

It is important to know one way or another because (and again this seems to be something that software developers fail to appreciate), a large investment in time and mental effort is required on the part of any user to learn a software package. Of course this situation is much aggravated by poor documentation. If VPhot is not to survive, then one might as well switch to a commercial alternative and stick with that.

If the problem is that the AAVSO does not have the resources, is there a way to enlist the help of members with design, coding and documentation? Has the AAVSO, for instance, considered making the source code available to (selected?) members, a la Linux etc, so that they can create and submit new functionality, help with testing etc?

I am also curious as to:

  1. Whether the AAVSO believes that VPhot performs (for variable star measurement and double star astrometry) at least as well as other (commercial) software;
  2. Presumably, the AAVSO developed VPhot for a reason (to ensure that observers analyzed and reported their data in a way that more closely conformed with AAVSO's requirements, perhaps?). What were those reasons and are they still relevant?
  3. Whether the AAVSO is really committed to VPhot over the long term;
  4. If the answer to (3) is “yes”, what the AAVSO plans to do in the near future to document VPhot appropriately;
  5. If the answer to (3) is “no”, why any AAVSO member should bother grappling with it (especially in the absence of documentation), rather than purchase a more “commercial” package?

Cheers

Paul (YPFA)

Paul,

Thanks for these

Paul,

Thanks for these comments.  I ca not directly adress any of your questions (since they are in the wheelhouse of the director, staff, and software support volunteers).   I think Arne shared in his annual report in May that Geir is visiting HQ this summer to collaborate on the future of VPHOT.

While I don't have satisfying answers, I am a councilor on the "Program Committee" who helps do SWOT analysis of our online offerings.  So I want to say that your comments echo and enhance concerns and compliments that have been aired about VPHOT.  They are helpful.  Thank you for bringing this back to the top of ongoing discussions.  I'm dropping this note because I want to encourage you and members who have constructive comments and concerns to air them out.  We might not always have answers right away.  But we are reading and acting on this kind of feedback.

-John Martin

Affiliation
American Association of Variable Star Observers (AAVSO)
VPhot

Hello Paul

I also serve with John on Council, and we did discuss the need for additional support for VPhot.  I would expect it to be continued for a long time.  I know Arne is working on a plan. 

 

I echo John's comments about providing feedback on things that you would like to see in regards to Vphot.  I expect Arne will weigh in on this shortly.

 

Gary

Affiliation
American Association of Variable Star Observers (AAVSO)
VPhot and its Future

[quote=WGR]

Hello Paul

I also serve with John on Council, and we did discuss the need for additional support for VPhot.  I would expect it to be continued for a long time.  I know Arne is working on a plan. 

 

I echo John's comments about providing feedback on things that you would like to see in regards to Vphot.  I expect Arne will weigh in on this shortly.

 

Gary

[/quote]

Thanks Gary.

You said "... on Council, and we did discuss the need for additional support for VPhot.  I would expect it to be continued for a long time.  I know Arne is working on a plan." 

That all sounds positive so far.

It will be interesting to hear Arne's view also.

Regards

Paul

Affiliation
American Association of Variable Star Observers (AAVSO)
VPhot and its Future

Thanks for your comments John.

You said "I can not directly adress any of your questions (since they are in the wheelhouse of the director, staff, and software support volunteers)".

Should I also post this on the General AAVSO Discussion forum, or will Arne et al get to see it anyway?

Cheers: Paul

Affiliation
American Association of Variable Star Observers (AAVSO)
VPHOT support

Hi Paul,

I am currently running the CCD School, so I am listening, but not responding, to many threads and emails.  As part of that school, I am running demonstrations using VPHOT as my primary source of software, so perhaps that will help indicate my strong support for the package.

I recognize that the documentation is getting out of date, and that will be taking high priority in the near future.  There are some other ongoing discussions as to new features and training volunteers.  By September, we should be able to announce our plan for the future of VPHOT.

Arne

Affiliation
American Association of Variable Star Observers (AAVSO)
VPhot support

Hello Paul

While I am a Maxim user, simply for other reasons, I have used Vphot on a couple of occasions and would myself, probably use Vphot if I was starting again.  It has the feature that its tied into the comparison star database, you can't make a mistake.  I have to copy that info down on my charts, and then input it into Maxim each time.  There is the possibility of an error. 

VPhot also gives you some nice options to look at aperture size, remove stars from an ensemble, etc as well as many more.  Its really slick.  I wish Maxim had all these same photometry features.

Paul, you sound like you might be familiar with this documentation issue.  Do you consider Maxim or SBIG well documented?  How much documentation do you consider adequate?  If the current videos were brought up to date, would that be sufficient?  How much work in person-years do you think it takes to fully document?  There is a forum for Vphot.  Should it be expanded?  Is it inadequate?  Should we have a Vphot discussion group on Yahoo like Maxim, Sbig, and others to provide a self help forum?  Do you have other ideas how to accomplish this?

Your input here could be very helpful.

 

Thanks

Gary

 

Affiliation
American Association of Variable Star Observers (AAVSO)
VPHOT issues

I consider myself as a heavy user of VPHOT.  My whole observing plan depends on VPHOT, without it I would have to scale back.  It could stand some improvement, IMHO, though.  Here are some of my thoughts (some of which have been expressed in this forum before, but with no response).

1.  There is a single point of failure - Geir.  That is not a criticism of Geir - he has done, and continues, a marvelous thing.  But he is only one person with, undoubtedly, another life and responsibilities.  Should he go away for any reason, VPHOT is doomed.  I espouse, along with others here, to open source VPHOT.  The Linux and free software movement is adequate testimony to the power of this idea.

2.  In my experience, VPHOT is not scalable.  It involves too many user input steps to get the job done.  For a few objects per session that is okay but with dozens or even hundreds it puts such a burden on the observer that few, if any, will use it.  If the leadership of AAVSO wants to increase the quality and quantity of VS measurements they might consider improving the tools - eg, transformations.  Can it be done?  Of course it can - it needs more workers.  Open source, maybe?

3.  VPHOT requires entire images to be uploaded to the cloud.  This is a burden and impediment to users with lower upload capabilities.  Forget it if you are on dial up.  Now I know that technology marches on and we can't let low tech users crimp the capabilities of others but a little software goes a long way towards equalizing opportunities.  The overwhelming percentage of image bits and bytes are sky background which VPHOT immediately starts to separate out and, for the most part, discard.  Lately I have noticed an uptick in huge (to my mind - 16 MB) images of time series some hundreds long that really tie up the processing queue for a long time - forget time sensitive results from others while this is going on.  We have discussed pre-processing images before upload to VPHOT before on this forum and it goes no where.  Limited manpower seems to be the big stopper.  Open source, maybe?

4.  Did anyone notice I'm in favor of open source?  Actually, I'm in favor of a systems approach to improving VPHOT.  To improve VPHOT more manpower is needed.  That could mean $$$$ but the open source movement has shown how to recruit free talent to get the job done.  Thus, open source is a means to an end - a better VPHOT for VS observers.

So, the first task is to embrace a systems approach to upgrading VPHOT.  It is not clear to me that Geir nor the leadership at AAVSO has the mindset to do this.  This is NOT a criticism of these fine folk.  I wouldn't expect any of them to be able to diagnose brain cancer either.  It's a question of their training and experiences to date.  Could they get the skills necessary to manage a systems approach to software development?  Of course, but how long will this take and do they want to do that?

At this point, I suggest the leadership of AAVSO consider going outside the organization to take on this task.  One thing to consider is to  look for a paid consultant with verifiable experience - of course we could look for a volunteer consultant, too.  That won't relieve the VSOers the task of defining the desired output in terms of accuracy, timeliness, usability, etc and coming up with a written RFP (request for proposals) that clearly delineates our needs and expected outcomes.  Perhaps a select committee drawn from AAVSO members and friends could start this process.

Jim Roe [ROE]

Affiliation
American Association of Variable Star Observers (AAVSO)
VPHOT

I find this thread puzzling.  My experience with VPHOT has been very positive and can't see why it won't be around for quite some time.  This "duck" seems alive and well.

I find most AAVSO users of VPHOT, I am in contact with, find it a useful product.  I have pretty much abandoned use of other commerical software to analyze my observations in favor of VPHOT.  Uploading images to the cloud alows me to process data from anywhere; yes, including my computer at work - don't tell anyone :-).  

I didn't find VPHOT especially difficult to learn, I don't feel it needs a lot of documentation.  With probably few exceptions, I can't  think of any commerical product out there that has printed documentation that isn't 1 or 2 revs out of date, and/or isn't buried deep in a (supposed) help file.

Hopefully Arne will tell us in September that VPHOT will continue to be a valuable part of the AAVSO support software that will be around for years to come.

Affiliation
URSA Astronomical Association, Variable Star Section (Finland) (URSA)
VPHOT and Open Source

I am also a heavy user of VPHOT and second Jim's suggestion to make VPHOT open source. I can see the obvious advantages of it but also can think some reasons against it, being in software business myself. 

Large images can make the processing queue slow, but that should be rather easy to overcome by using more virtual servers. If this is running in the Amazon cloud it should be easy to start new processing servers automagically when the queue is getting too long. I have been there several times waiting long time to measure some time critical data.  I am always using subframes to make uploading and processing as quick as possible, but many users seem to load full frame images.

I have successfully processed more than 10 000 images for the ongoing HSTCOS campaign with VPHOT.  Often the data points have been in the AAVSO database within few minutes after the images have been taken remotely in Chile. Overall I am a very happy user. Missing or dated manuals/videos/documentation has never been an issue for me, I have been able to learn VPHOT just by the good old "trial and error" method.

Big thanks to Geir for making all this possible and for the excellent support whenever I have needed some.

arto

Affiliation
American Association of Variable Star Observers (AAVSO)
VPHOT and its future

[Arto wrote:

 

"I am always using subframes to make uploading and processing as quick as possible, but many users seem to load full frame images."

Are these subframes pre-processed from full frames before uploading?  Or are you subframing in your original exposure thereby creating smaller images to upload?  Would any of this be a general recommendation to VPHOT users?

"Often the data points have been in the AAVSO database within few minutes after the images have been taken remotely in Chile."

This is very interesting to me.  Have you found a way to bypass the manual steps of selecting image(s), selecting sequence, etc and getting the data submited to WebObs directly?  Are you submitting images as they come out of the camera or waiting until you have a 'batch?"  How fat is your data pipe?

Jim Roe [ROE]

Affiliation
URSA Astronomical Association, Variable Star Section (Finland) (URSA)
Processing steps

I am imaging with subframe. I am usually using 800x800 pixels of the 2kx2k chip (1.3 Mb vs. 8 Mb per image). I strongly recommend using subframes. With ACP/MaxImDL this is simple as setting "#SUBFRAME 0.4" in the script file. MaxImDL can calibrate subframes from the full frame calibration images.

My usual number of images per target is 5 and I can upload them while imaging the next target. Internet connection is quite fast, it takes about 10s per image.  Pre-processing the images in VPHOT is usually slower than the file transfer, but the images appear in the VPHOT pretty soon. Then I just select the new images, click "Time Series" and select the correct sequence (saved when the first image of that target was measured) and click "Start the Analysis".  Then on the "Results" page I click "Create AAVSO report" and "Create Report File". Then "Open WebObs (AAVSO)" and submit the data. All this is maybe 15 mouse clicks and takes less than a minute and the data is in the database.  Easily done while the remote observatory is taking the next 5 images. Of course when there is longer time series it takes longer to upload the images (its just computer time), but the photometry steps are done as quickly as with the five images.

arto

Affiliation
Madrid Astronomical Association M1 (Spain) (AAM)
Subframe looks good

[quote=oar]

I am imaging with subframe. I am usually using 800x800 pixels of the 2kx2k chip (1.3 Mb vs. 8 Mb per image). I strongly recommend using subframes. With ACP/MaxImDL this is simple as setting "#SUBFRAME 0.4" in the script file. MaxImDL can calibrate subframes from the full frame calibration images.

[/quote]

This is very interesting to me. My camera produces an 8.3 Mpx frame, wich would collapse VPhot server processing qeue; fortunately I use 3x3 binning mode, and my pics are 1108x834 pixels if size. Using subframe would reduce more my photometric images, make Vphot uploads shorter and reduce server tasks.

Affiliation
Madrid Astronomical Association M1 (Spain) (AAM)
Regarding the topic of this

Regarding the topic of this post:

I am very happy that Vphot is available to me. This is the best photometric tool I ever used. It is easy and intuitive to use, and lets control the quality of your data.

I agree with Paul in that a good documentation is needed, but I think a medium skilled user can begin to use Vphot in a minimum time.

Vphot deserves a long life!!

Affiliation
Astronomical Society of South Australia (ASSAU)
Software without docs and open source

I just wanted to make a couple of remarks from the standpoint of a VPHOT outsider, as lead developer of VStar:

 http://www.aavso.org/vstar-overview

VStar is in a similar state with respect to documentation. I am in the process of rectifying this as per this forum topic: http://www.aavso.org/vstar-user-manual-project

As with all volunteer efforts, the key thing is to find people who are motivated enough for a particular task. With one person it's a slow task. Adding another can be a surprising help.

I think open source has worked well for VStar, via SourceForge in this case: https://sourceforge.net/projects/vstar

Of course, making something open source is no guarantee of attracting developers or of high quality. Processes must often be put in place to provide any kind of quality guarantees. However, it does help to guard against loss of developers from a project, so long as the code base is habitable and there's some modicum of guidance for developers.

David

 

 

Affiliation
American Association of Variable Star Observers (AAVSO)
VPHOT

David wrote:

"As with all volunteer efforts, the key thing is to find people who are motivated enough for a particular task. With one person it's a slow task. Adding another can be a surprising help."

Exactly.  Sometimes volunteers will appear spontaneously but a pro-active approach to recruit them (ie, ASK for volunteers) is usually more productive.

I see the essential requirement here (as in other areas of life) is leadership.  Someone needs to assume this mantle and organize the many details (it's been done before in innumerable software development projects and there is no shame in copying).  It's a matter of building a 'machine' that will crank out desired results.  Yes, it will take some time and resources but it is a one-time capital investment that will bear dividends in the future.  It also takes some training and/or experience which may or may not be listening within our little sphere.  But it exists!  That's why I suggested AAVSO leadership consider seeking an outside consultant.

But before even this, the will do do it is needed.  Is there any sign such a will exists within AAVSO leadership?

Jim Roe [ROE]

Affiliation
American Association of Variable Star Observers (AAVSO)
VPhot and its Future

 

Thanks to everyone that responded to my initial posting, particularly the expressions of confidence that VPhot will be around for the long haul. In light of those responses, I thought it might be useful to briefly re-state / clarify my position re VPhot.

 

I regard VPhot as a very good package to use and am not really criticising it per se. It’s only the approach to documentation that I am taking issue with. I believe we need two kinds of documentation with any software package:

 

1.   Ordinary user documentation that explains how to use the package. This should be presented in such a way that it will support newbies as well as experienced users. It does not need to be a written manual - it can be video tutorials, or whatever else works. My personal preference is to have something printable because it can often be difficult to work through on-line tutorials while, at the same time, having VPhot open and running. But that’s just me, on-line tutorials are fine.

 

2.   Documentation about the internals of the package, including design documentation (how the software is structured), what algorithms are used for things like centroid determination and whatever else the software does. Many software packages are essentially opaque (black boxes) - you simply have to trust that they are working OK. But I don’t believe this is good enough, given what we are trying to achieve in the AAVSO.

 

From the point of view of quality software development methods, I believe that the documentation should never lag the software release at all - it should always be up to date. If there are some commercial packages around that do not meet this standard, then so much the worse for them. We can do better. Here are some thoughts to support what some might see as my “uncompromising” position on this:

 

1.   Keeping the documentation up-to-date is not as hard as it looks. Essentially, this is because the production of documentation (both kinds) should simply be a by-product of design and testing in any quality software development process. In other words, the documentation is needed anyway to do good design and testing. Conversely, its absence can make one wonder a little about the quality of the approach used to develop the software in question.

 

2.   I think of AAVSO as being an organization of amateur astronomers who believe in working to professional standards. The collection of good VS data and its subsequent analysis requires an important sequence of steps to be done to a high standard - we require a good scope, good CCD, good data transmision, photometry, data analysis, etc. Software plays a critical role in more than one of these steps. We should not accept a lower standard for the  software than we insist on for the “hardware” links in the chain - the optics, the electronics and so on.

I don’t have much to suggest in terms of features that VPhot ought to have or things that VPhot should do differently. However, I note that both ROE and OAR have suggested several possible improvements in their postings.

 

Gary (WGR): You raised a number of questions about “documentation” in your posting. Some brief responses: a) Bringing the current tutorials up to date would be a good first step; b) How much documentation is “adequate”? Well, I guess everyone would have a different opinion on that, but I am not suggesting we go overboard. I think the key requirement is that it be up-to-date. If people then find it less than adequate, they can always ask for clarification, but that “clarification” then needs to be incorporated quickly into the available documentation; c) In a sense, I don’t think it takes any “person-years” to adequately document a software package, beacuse it needs to be done as you go along anyway (see my comments above re documentation being a natural byproduct of good development practices). d) I think the existing forum for VPhot is a good thing. Should it go to a Yahoo-type self-help forum? Maybe. One of the things I noticed immediately on looking through the existing VPhot forum is that some questions seem to go unanswered altogether (including past queries about the future of VPhot and when the tutorials might be updated). This shouldn’t happen at all.

 

For my part, I am more than happy to help out on this matter wherever I can, bearing in mind the geographical fact that I don’t live in the States. However, the networking tools we have at our disposal should ensure that distance is not a serious problem ...

 

I look forward to the projected announcement (in September) regarding AAVSO’s plans for the future of VPhot. I think it is a great concept and a great tool.

 

Regards

Paul (YPFA)

Affiliation
American Association of Variable Star Observers (AAVSO)
VPhot and its Future - Dead Thread?

I read this thread with great interest originally.  There were a lot of interesting points raise regarding outdated / overly lean documentation, new features as well as suggestions for open sourcing. 

Then the thread appears to have died.

Fast forward to March 2014 and obviously VPHOT hasn't been axed, but what, if any decisions have been made regarding the concerns and suggestions raised in this thread?

Last year as a n00b to photometry as well as VPHOT it was an endless struggle for me.  Though my campaign images came directly from one of the AAVSO scopes, which helped eliminate a lot of steps on my part (already plate solved and calibrated, etc), I still struggled with performing the analysis in VPHOT.

I found the tool very easy to use on the surface - click-click-click and you're ready to upload your data, but not being an expert with photometry I had ZERO confidence in the quality of my results.  Just by adding or removing comparison stars I was getting what I felt were signifcant variances in manitudes of my target.  Rather than taint the AAVSO database with garbage and unable to elicit someone to at least just perform the same analysis on a few of my images to let me know if I was in the ballpark, I gave up and abandoned the campaign.

Maybe I needed (still do) more handholding than someone who should have even been attempting to use the tool, but again, with this thread the fact that others shared similar user guide/documentation concerns I had hope.

Sincerely,

Wayne

Affiliation
American Association of Variable Star Observers (AAVSO)
VPhot and Its Future

Hi Wayne

I produced the original posting on this topic. I felt quite strongly about it at the time and still do.

"Then the thread appears to have died", as you say …

One reason for this is that I had said pretty much all I had to say on the matter, and I even finished up the thread with a sort of "summary" or "status" posting. So I ended up saying most everything twice, anyway. But that was way back in July 2013. 

The second reason is that, apart from a few supportive responses, virtually nothing constructive came back (officially) from AAVSO concerning the points I had raised. There was some mention by Arne about an update in September (2013) regarding plans for VPhot, but I have not been able to find anything to that effect in the newsletters. In light of this silence, To keep posting on this matter just felt as though I was "flogging a dead horse".

Late last year, I discovered that Mike Simonsen was working on the VPhot documentation and on a VPhot course, so I wrote to him offering my help. He was working on it with Geir and, I think, Ken Mogul. Mike sent me the documentation, which I took a look at , but I concluded that the work was so well advanced and so closely connected with what was in each of those persons' heads, that I could add very little. So that's where I left it.

Like you, I recently discovered that the Choice course was being held and I have enrolled for it. I am really looking forward to it and hope to learn a lot.

Six months on, here are my thoughts ...

1.  It is pretty clear that many of the active AAVSO members (who are doing such things as maintaining VPhot) are greatly overworked.

2.  For this situation to change, these folk (the "over-worked") must find a way to permanently hand certain duties over to other members. In the short term, this might cause even more work. AAVSO should call for volunteers or at least respond to those who have volunteered already. I am disappointed that my offers to help, save one, have more or less fallen on deaf ears …

3.  Sticking with VPhot for a minute, I have spent my working life as a software developer and enterprise architect. I don’t pretend to know everything about it, but I believe that I am perfectly capable (in this digital age) of remotely managing and maintaining the VPhot code and its associated documentation, provided I have access to the relevant materials and am given some help in the transition. This activity might well require me to enlist the help of some other AAVSO members, also, depending on the volume of the work. No doubt there are other AAVSO members capable of doing this job, but I am definitely putting up my hand.

4. My experience with the AAVSO forums has generally been disappointing - there is my less than satisfactory experience with this VPhot thread, but there is also the fact that you don’t have to look too far in several other forums to find postings that have never had a response of any kind. Is no one officially monitoring these forums? If not, they are of limited use.

5. I suspect that there are a lot of experienced people in AAVSO who, over the years, have forgotten what it is like to grapple with variable star observation for the first time. In general the introductory manuals are pretty good, but once these have been mastered, there is an enormous gap between this entry-level degree of knowledge and real expertise - a gap which is very difficult to bridge: there is virtually no documentation to plug the gap and, as I said above, the forums leave a lot to be desired in this regard.

Regards

Paul (YPFA)

Affiliation
American Association of Variable Star Observers (AAVSO)
vphot etc.

I'll respond to a few of Paul's many (useful) comments.

First, regarding forums: we moved to the forum concept for many reasons after a decade of mail-lists.  It is not perfect, but it is much better than mail-lists, and we have far more members/observers contributing politely to the forums than we did with the earlier structure.  I am subscribed to ALL of the forums, and read each and every post.  I classify the posts into several categories, and respond accordingly: any post that mentions my name gets responded to quickly; any post that is HQ-related may get routed to another staff member; any other post is usually read, but I give other readers the opportunity to respond before I jump in.  Not every reponse has to come from me (for technical questions, there are people with far better expertise than I have in many areas), and not every post needs a response.  If you have found some where an official response is needed, let me know (privately) and I'll take care of it.

I agree that Geir is a single point of failure for VPHOT, and we've been working on the problem.  Paul is raising his hand to help out (thanks!), and I'll reach out to him shortly.  One of the missing pieces was better documentation, and as you mention, our volunteers and staff have done that, creating an extensive manual that will be released shortly, as well as a full CHOICE course on using VPHOT.  I think one of the items we could be better at is communication, and towards that end I will resume my monthly HQ status reports.  One thing to remember is that much of the AAVSO work is being done by volunteers, often with supervision from HQ, but with a typical volunteer's schedule: we have to be patient, as many have day jobs and other commitments.

While our documentation is pretty good, and I think our introductory manuals are particularly noteworthy, I agree with Paul that the next level of support is largely missing.  Much of that can be given through mentoring - if you have difficulties, you just have to ask for someone to lend a hand.  We have an official mentoring program for members, and posting on forums with questions also yields useful responses.  Some could be improved with a better list of intermediate texts, so that the observer can purchase an external book to give guidance.  Providing intermediate-level instruction is a good avenue for expansion, and I hope that we can make some progress in the next few years.

Arne

Affiliation
American Association of Variable Star Observers (AAVSO)
VPhot and Its Future

Arne

 

Thanks for your response …

 

Point taken with regard to the forums. The use of mail-lists was before my time so I don’t have any direct experience with that. I can see that the forums are a much better solution, though.

 

I like the idea of the monthly HQ status reports resuming. I look forward to reading them.

 

I also like the idea of “a better list of intermediate texts”. Sometimes I find it impossible to pose a sensible question to a mentor, because I lack sufficient background in a particular area to even formulate the question properly. I would be happy to consult books, however, particularly if some guidance was available on the website as to which books were most promising, best for particular topics, etc. That would also tend to save the time of the mentors as they would not (as a rule) have to answer questions that are covered elsewhere. Does that make sense?

 

Finally, I hope I didn’t come over as too critical. I appreciate that the AAVSO is a volunteer organisation (with volunteers all having day jobs and / or other commitments) and am continually amazed by what it has achieved over the years.

 

On the other hand, I thought I needed to give some feedback for the sake of the better functioning of the AAVSO (as I see it). But sometimes, it’s hard to get the balance exactly right (especially in e-communications) between a bit of (negative) feedback and a genuine appreciation for what the AAVSO has done and continues to do for the astronomy community.

 

Regards

Paul

Affiliation
Royal Astronomical Society of Canada (RASC)
vphot etc.

[quote=HQA]One of the missing pieces was better documentation, and as you mention, our volunteers and staff have done that, creating an extensive manual that will be released shortly[/quote]

I started using VPHOT for the first time recently and have enjoyed it immensely - however some documentation in addition to the videos would be excellent to answer questions. When will these docs be available? Thanks!

Regards,
  Gord

Affiliation
American Association of Variable Star Observers (AAVSO)
VPhot User Guide

Hi Gord,

We just concluded the first CHOICE course on 'How to use VPhot'. Part of the process was creating and editing a user guide for the software that we could also use as the text for the course. As part of the course, I had the students point out typos, errors and omissions, which they did very effectively. This allowed us to publish the improved version, VPhot User Guide 3.0, which members can now download here.

[Note: this is a member access only page, so if you are not a member you will get an error message if you try to access this page]

I have also created a thread in the VPhot Forum called 'VPhot User Guide Suggestions' where users can make suggestions for improving the user guide and we can track and implement them as time and creativity allow.

I expect version 4.0 will come in the next few months, incorporating some of the suggestions made in the CHOICE course that have not been adopted yet and any new suggestions from the forum thread. I will make an announcement in this forum when that update becomes available.

Mike Simonsen
AAVSO

Affiliation
American Association of Variable Star Observers (AAVSO)
VPhot and the VPhot User Guide

Note added: In original post I mentioned a v4 manual. Wrong, its v3! Sorry for the mistake.

I just finished the VPhot course and have read the new manual (v3) that evolved during the course based on feedback by other students with changes incorported by Mike . Although I have used VPhot since its Photometrica days, I found the course very informative and the manual quite good.

One illuminating part of the course for me was better understanding how to use ensembles more effectively. Lesson I took home: use as many comp star as possible and don't be put off by the resulting uncertainty so long as it is reasonable -- the goal is not to minimize the uncertainty but to report an uncertainty that reflects the conditions of the observation. Another lesson: spend lots of time studying each comp star: some are too close to the edge of the image, some appear to be doubles, some are iffy, some too dim, in one case the comp was the variable (!).T hese lessons are unique to VPhot, but the way VPhot works makes such things easier for me to explore.

Another thing to understand about VPhot is the color coding. Deep red means the comp deviates by 3-sigma. But this is relative. You can continue to eliminate comps and you will find additional 3-sigma comps that did not turn up in the first round because after eliminating the first 3-sigma comp the remaining comps are evaluated again. The elimination of the first one will recalibrate the overall uncertainty. No doubt you can continue to do the elimination until you have a single comp. But this destroys the value of using an ensemble approach. So, I have taken the step of being very careful after the initial elimination to minimize eliminating additional comps based on only the color code. My uncertainties may not look so good, but I can live with them.

Finally, the ability to save ensembles for future use and load them automatically leads to consistency: groups of observers can even agree on the comps for a joint compaign and they can be different for each filter. All of this speaks, to me, of a program I want to use (and do). I would encourage others to take the course and/or read the new manual and explore the program.

Thanks for a great course Mike.

Ed