A Suggestion Toward Greater Queue Efficiency

Wed, 07/22/2015 - 17:08

I've noticed that the upload queue runs a lot slower on images that require some kind of a WCS solve.  I've observed this to the point where it takes almost no time to to upload an image that has WCS information included and requires no plate solve.  

My suggestion is that VPHOT should have two upload portals:  one that performs a plate solve -and- one that does not.  If you put an image requiring a plate solve in the no solve queue you are just SOL but little processor time has been spent on that file so no worries.  I think this might improve the efficiency of the queue process for VPHOT and prevent some of the long backlogs we have seen lately.

American Association of Variable Star Observers (AAVSO)
separate upload for solved images

I think this is a very good idea! 

It would be very nice for those who do the plate solution before uploading to have access to the "carpool lane".  This would encourage local plate solving and speed the upload processing for everyone.


American Association of Variable Star Observers (AAVSO)
Separate queues

Hi John,
this is indeed a good, and hopefully simple to implement, idea. Still, there are IMHO few open questions. The most important is - WCS in what format?
I have here two examples:

  • FOV of our observatory's 60cm F/12.5 reflector is pretty small. Fields solve perfectly without any distortion corrections in WCS - plain linear solution is all that we need there,
  • FOV of our robotic telescope is 37'x37' and that requires definitely at least second order corrections to linear WCS.

While that robotic telescope is controlled by ACP, images from that system are plate solved by PinPoint. Unfortunately no program from my arsenal is able to use those corrections. Instead, I have to solve all field by myself using e.g. local astrometry.net, basically doing that job from scratch.

What about VPhot? As I understand, it is using PinPoint as plate solving engine. But does it understand corrections in TAN-SIP format (IMHO de facto standard nowadays in pro community)? If it doesn't, what happens then to submitted frames? Would they be treated as having linear WCS (or no WCS?)?

Well.. such questions :-)

Best wishes,

American Association of Variable Star Observers (AAVSO)
Plate Solving by VPhot

Hello John

The VPhot team has discovered that a major slowdown in the Plate Solving by VPhot is caused by issues with the FITS headers.  These come from both observers and remote telescopes.  

I like your idea of the fast lane for those images that are plate solved.  Perhaps George and Ken have thought about how to implement that.  

We also need to encourage users to upload using the Wizzard, which checks the fits header for issues.  Only a very small number of images will pass the Wizzard, and still hang the Plate Solve.  One issue that has received considerable work is the choise of which of the 4 catelogs are used, in which order, and how long the timeout specs should be.  Lots of Progress here.  

The VPhot Team is planning to make a report to membership soon.