Which software to use?

I use a selection of software but mostly AIP4WIN. It is very popular with lots of AAVSO contributors.

I output both raw data and AAVSO upload versions.  It is then easy to average results etc in a spreadsheet and modify the already created upload format in a text editor.

I also use MIRA but motly just for preprocessing.

Cheers

Terry (BHQ)

 I have only fiddled with Canopus a couple of times and that was a few years ago. Therefore it would be hard for me to compare others to it. 

I also found Maxim DL to be very limited particularly since you must have a comparison star to use the photometry tool and the information window aperture tool is not very accurate and is not recommended for photometry. You can't get raw magnitudes, at least I found no way to get them and for certain things like establishing transformation coefficients you don't want to do differential photometry. You want the raw magnitudes.  

Many people use AIP4WIN. I have used it in the past and it's pretty good and readily available as freeware. More than 5 years ago I tried a number of different packages and decided I liked Mira-pro the best. It was developed by Michael Newberry,  one of the original developers of IRAF. It has robust GUI interfaced algorithms for photometry and other image analysis tasks - including source extractor -  and one of the slickest image calibration pipelines I have ever seen. The problem is it is expensive - on the order of Maxim DL or a bit more if you get the scripting add-ons. This was developed as a Windows program but I think it is also available for the current MAC OS. 

Of course there is IRAF itself or the version integrated with Python, PYRAF. If you found Canopus too complicated you will find these ridiculously so. IRAF, however is regarded as the gold standard of Image Reduction and Analysis (Facility) software for astronomy. It is versatile, has lots of add-on packages to do almost anything you can imagine, has a image viewing interface called DS9 that is incredibly versatile but it has a very difficult learning curve. There is also a free package called image J. It was developed for medical imaging photometry as were many of the best photometry packages including Mira-Pro (because that is where the money is). Image J is quite a good package BUT the last time I looked it did not have a conversion into magnitudes. You had to do that as a manual step at the end. It has some very interesting and helpful features, however and it is free. 

Finally, I have used VPhot and have not had unexpected results. It seems to work well. I don't know if there is a version that you can download to your computer. You could in its original implementation as Photometrica and perhaps it still can be. that would be an interesting question to ask on the forum. I don't see a post on that topic. I agree Uploading images to VPhot is a problem. It was bad enough with my old ST7 that was about 0.8 Mbyte per image. With my new camera at 16 Mbyte per image, it is essentially impossible for more than a very few images over my DSL connection at 0.7Mbps. If you have 10 Mbps it might not be such a pain. It would be great if there were a VPhot client that ran on user computers to do all the heavy lifting on the image with automated interfaces to AAVSO for Variable star search comp stars, and reporting. That could also greatly reduce the storage and traffic on AAVSO servers. I am not competent to evaluate the complexity of such a development project, however. 

I am sure that I haven't scratched the surface of all the photometry packages that are out there. There are probably a whole bunch I have never heard of or have forgotten about. 

Brad Walter

PS: 

Perhaps I should be specific about the meaning I apply to "raw magnitude" what I mean is precisely

-2.5*LOG(Netcounts*GAIN.EXPTIME)

So it is a negative number, or if you offset all measurements by the same sufficiently large constant you can make them positive i.e. -2.5*LOG(Netcounts*GAIN/EXPTIME) + 25

So not only is it not transformed, it isn't referenced to a comparison star magnitude.

I use the term "instrumental magnitude" for a magnitude that is referenced to a comparison or standard star magnitude but which is not transformed.
Tmag_raw - Cmag_raw + Cmag_sequence 

A Confusing Vocabulary:
The terms raw, instrumental  standard, differential and absolute are not uniformly used and can have conflicting meanings in different contexts or different meanings in the same context when used by different people.  It leads to confusion. The term standard as used in the MTYPE field of WebObs, for example is a bit of a misnomer although it is completely explained in the link in the notes, if you read that far. I would only use the term standard to apply to the magnitude of a recognized standard star. I wouldn't even use it to describe a magnitude that had been transformed to a standard magnitude scale. I would use "transformed" to describe that. I don't even use "standard" to describe the chart magnitude of a comparison star. I use "sequence" magnitude or "reference" magnitude to describe comp star magnitudes (unless they are recognized standard stars) because most sequence star magnitudes are only transformed to a standard magnitude scale. They are not sufficiently measured to qualify as a photometric standard stars. 

I certainly would never use the term "absolute" magnitude to mean anything other than a magnitude transformed to a recognized standard and adjusted for distance and interstellar extinction to an observational distance of 10 parsecs (see 2.3.3 in Binney and Merrifield, for example)  but you sometimes see it used to mean an instrumental magnitude, 
Tmag_raw -Cmag_raw + Cmag_sequence,

to distinguish it from a differential magnitude,  
Tmag_raw - Cmag_raw.

To add to the confusion, either of these two magnitude types are most frequently produced by AAVSO members using differential photometry vs. all-sky photometry. So differential photometry does not necessarily result in a differential magnitude, but it can. It just depends on which formula you use.

Some of these distinctions are only the vocabulary choices of one journeyman amateur, but I think they make distinctions much clearer, particularly trying to explain things to someone new to photometry. 

>  Many people use AIP4WIN. I have used it in the past and it's pretty good and readily available as freeware. 

AIP4WIN is not freware, you need to buy the book "Handbook of Astronomical Image Processing" to get the software. Around 100 bucks. If you find AIP4WIN as a "free download" somewhere, it must be an illegal copy.

A package that hasn't been mentioned yet is IRIS (which is freeware). It it nice for image calibration and basic photometry, but doesn't offer "batch" photometry features like AIP4WIN, AFAIK. Idt does have a little scripting feature build-in, tho. 

If you are working on photometry of very crowded fields, SourceExtractor (under Linux) might be an option for source identification and photometry. Anyway, anybody not afraid of Linux and configuration-rich Pro tools can try the "SciSoft" package from ESO, a compilation of pro tools which has IRAF, SourceExtractor and a ton of other tools bundled together. 

Cheers

HBE

I hope Brad meant that IRAF was readily available as freeware although anything is possible. 

AIP4WIN is a commecial package authored by James Brunell and Richard Berry and sold  for about $100.   In my view it is an excellent program and for your 100 bucks you also get an excellent book that every imager should have on their book shelves.  Used by many AAVSO observers.  I have used it from time to time.  There is a limit on the number of computers that you can load AIP on.

I generaly  do long time series and primarily use MaxIm because it is a very robust program that provides a lot of useful support like PinPoint and stacking.  You can get raw data from it but it takes some fiddling.  I always import my nights data into Excel for plotting, further analysis and  checking.  I have  also written some crude and rude scripts so I can edit the AAVSO output file if I need to. I use MaxIm when I want to calculate my transform coefficients but it has been awhile

I don't think MaxIm would be useful for all sky photometry but works fine for differential photometry.

Finally there is a fairly new free-ware program available....LesvePhotometry.  It has some interesting features and resembles VPHOT in some ways.  It, in theory, will do a very large number of images without running into memory problems.  It is very fast to use.  I've had some problems with it and am not using it.  But a number of high volume observers are using it and are very happy.  I believe it requires a full PinPoint license.  You can find out about it at

http://www.dppobservatory.net/AstroPrograms/Software4VSObservers.php

Hope this helps.

Jim Jones, JJI

AIP4Win is apparently popular, perhaps being an early and inexpensive entrant.  However, set up and data entry are tedious to say the least.  The program invites errors, and if your pointing is not fairly precise between images or you cross the meridian it is difficult to get through a large stack of image without upset.  Even having learned its idiosyncrasies I still find the program a pain to work with.

http://c-munipack.sourceforge.net/

Is a wonderfully straight forward shareware program with lots of capability but it does not do AAVSO style reports or Std. Magnitudes, only instrumental. 

I normally use:

http://www.dppobservatory.net/AstroPrograms/Software4VSObservers.php

This is also a shareware program and it runs circles around AIP.  Drawback is you have to have a pinpoint license costing $200, but as AIP is half that anyway, there is no contest in my mind.

Data entry and set up are a fraction of the effort as with AIP and almost devoid of error potential, especially if you use the separately available tool that allows importation of data from the AAVSO website.

Once the sequence is established, you enter the index name you assigned to the star, click “go” and highlight the images in your file and off it goes.  Using pinpoint to find the relevant stars, Lesve automatically processes the images, generating all manner of data in real time as it does so. 

It can generate four different report styles (including AAVSO) and an error report where needed.  It will filter out images based upon preset parameters, such as image elongation, maximum ADU count, minimum SNR.

I have found one star our of nearly a hundred I have gathered data on over the last three months that it can’t resolve.  I suspect some adjustment would overcome this but I just have not focused on it. 

Current short comings, it does not include excluded images for violating the preset parameters in the error report, and I wish the optional excel report include the reference star’s instrumental magnitude reading instead of its stated magnitude.  However, these are minor issues that perhaps will be addressed in the future as the owner has been pretty good about upgrading the program.

Mira Pro 7 has a 1 click output to the Standard Extended format. I end up not being able to use it much of the time however because I am doing mutlicolor photometry in say VBBV, or IRVBBVRI blocks (or binned multiples of these blocks) and I am averaging the measurements in each color so that the resulting midpoint times of the averaged images in the various colors are as close to the same as possible. I could stack and average the images themselves and then do the photometry but I don't. I do the photometry on the individual images and average the results in a spreadsheet so the feature doesn't help. I do use it, however, if I am doing single color photometry.

Attached is a sample output CSV file from Mira-Pro 7 using an ensemble of comp stars. If you don't plate solve the images before doing photomtry the X and column values are the same and the Y and row values are the same. 

One of the things I shold have mentioned about Mira Pro is tht it has excellent documentation even compared to Maxim DL, which I think is darned good,  and much better than The Sky.  It is a real commercial product not a hobby project. I don't get commissions for recommending Mira I just like it, but, as I mentioned, "it ain't cheap." 

Brad Walter

Everybody thanks for the replies! I didn't hear about Lesve and as I have pinpoint it sounds interesting, so I will give it a try...

I will add an option in LesvePhotometry to report the HJD instead of JD. The next release will be available in one or two weeks.

Pierre de Ponthiere