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VPhot , PinPoint, WCS

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Ed Wiley_WEY
Ed Wiley_WEY's picture
VPhot , PinPoint, WCS

Some of my images are not being processed by PinPoint, with the message below. Curiously, the same fields on different nights are being plate solved. I am wondering how to solve this problem. Typical file is attached as a jpeg and I can share images when and if they reload.

BTW: Trying to update WCS by selecting a correctly solved V1117 Her image does not work.


V1117 Her_V_120sec_2x2_2017-07-18_230025_frame3_CAL.FIT
7/19/2017 5:11:52 PM
PinPoint Error

There are too few catalog stars in the area for reliable matching. Increase the catalog star faint limit, or use a more dense catalog.

Eric Dose
Eric Dose's picture
What I've tried:

Your image looks to me as though it should solve, but it does look noisy for a calibrated image. You may want to go directly to the experts on DC-3's PinPoint forum.

I do share your experience: PinPoint simply leaves unsolved 2-5% of my good images, this during my ACP acquisition runs of 30-250 FITS/night. It was my worst photometry processing headache, to the extent that I wrote and now apply to every session an R script that opens every single downloaded FITS and scrutinizes several header keys for reasonable plate solution before I allow processing to continue, including for those occasions when I use VPhot.

For FITS that PinPoint initially left unsolved, I used to adjust PinPoint catalog settings, etc, with some success. Full PinPoint seemed to slightly outperform the limited LE version.

But recently for FITS without plate solutions, I've gone straight to TheSkyX's 'ImageLink' plate solver rather than tweaking PinPoint's settings. PinPoint may well be more accurate astrometrically, but for photometry I need robustness rather than the last bit of accuracy. And ImageLink is robust--in my recent experience, if ImageLink can't solve an image, you'll probably see something wrong with it.

pablotwa's picture solved it easily here's the fits header from the jpeg you posted. I also iincluded a view of your jpgeg superimposed on the world wide telescope for you.


Image #1
    SIMPLE  =                    T / Fits format
    BITPIX  =                    8 / bits per pixel
    NAXIS   =                    3 / number of axes
    NAXIS1  =                 1023 / image width
    NAXIS2  =                 1023 / image height
    NAXIS3  =                    3 / image planes
    COMMENT Original key: "END"
    COMMENT --Start of WCS solution--
    COMMENT --Put in by the new-wcs program--
    WCSAXES =                    2 / no comment
    CTYPE1  = 'RA---TAN-SIP' / TAN (gnomic) projection + SIP distortions
    CTYPE2  = 'DEC--TAN-SIP' / TAN (gnomic) projection + SIP distortions
    EQUINOX =               2000.0 / Equatorial coordinates definition (yr)
    LONPOLE =                180.0 / no comment
    LATPOLE =                  0.0 / no comment
    CRVAL1  =        249.773142042 / RA  of reference point
    CRVAL2  =        9.80474204544 / DEC of reference point
    CRPIX1  =        516.427787004 / X reference pixel
    CRPIX2  =        493.187322349 / Y reference pixel
    CUNIT1  = 'deg     ' / X pixel scale units
    CUNIT2  = 'deg     ' / Y pixel scale units
    CD1_1   =   -0.000294105993972 / Transformation matrix
    CD1_2   =   -4.54434567297E-05 / no comment
    CD2_1   =    5.04767696214E-05 / no comment
    CD2_2   =   -0.000294506927996 / no comment
    IMAGEW  =                 1023 / Image width,  in pixels.
    IMAGEH  =                 1023 / Image height, in pixels.
    A_ORDER =                    2 / Polynomial order, axis 1
    A_0_2   =    4.86368064385E-06 / no comment
    A_1_1   =   -1.32817401792E-06 / no comment
    A_2_0   =   -4.72904386825E-06 / no comment
    B_ORDER =                    2 / Polynomial order, axis 2
    B_0_2   =   -1.40513416337E-06 / no comment
    B_1_1   =    -5.5307199273E-09 / no comment
    B_2_0   =    2.84346235394E-07 / no comment
    AP_ORDER=                    2 / Inv polynomial order, axis 1
    AP_0_1  =   -1.34955709409E-06 / no comment
    AP_0_2  =   -4.86441148546E-06 / no comment
    AP_1_0  =    3.49115873447E-06 / no comment
    AP_1_1  =    1.32640798738E-06 / no comment
    AP_2_0  =    4.72890466375E-06 / no comment
    BP_ORDER=                    2 / Inv polynomial order, axis 2
    BP_0_1  =    5.12231109362E-07 / no comment
    BP_0_2  =    1.40529566086E-06 / no comment
    BP_1_0  =    -1.9140760455E-07 / no comment
    BP_1_1  =    5.64893400804E-09 / no comment
    BP_2_0  =   -2.84371311342E-07 / no comment
    HISTORY Created by the suite.
    HISTORY For more details, see .
    HISTORY Subversion URL
    HISTORY Subversion revision 22686
    HISTORY Subversion date 2013-05-06 22:33:22 +0000 (Mon, 06 May
    HISTORY   2013)
    HISTORY This WCS header was created by the program "blind".
    DATE    = '2017-07-19T19:27:00' / Date this file was created.
    COMMENT -- blind solver parameters: --
    COMMENT Index(0): /data1/INDEXES/200-current/index-219.fits
    COMMENT Index(1): /data1/INDEXES/200-current/index-218.fits
    COMMENT Index(2): /data1/INDEXES/200-current/index-217.fits
    COMMENT Index(3): /data1/INDEXES/200-current/index-216.fits
    COMMENT Index(4): /data1/INDEXES/200-current/index-215.fits
    COMMENT Index(5): /data1/INDEXES/200-current/index-214.fits
    COMMENT Index(6): /data1/INDEXES/200-current/index-213.fits
    COMMENT Index(7): /data1/INDEXES/200-current/index-212.fits
    COMMENT Index(8): /data1/INDEXES/200-current/index-211.fits
    COMMENT Index(9): /data1/INDEXES/200-current/index-210.fits
    COMMENT Index(10): /data1/INDEXES/200-current/index-209.fits
    COMMENT Index(11): /data1/INDEXES/200-current/index-208.fits
    COMMENT Index(12): /data1/INDEXES/200-current/index-207.fits
    COMMENT Index(13): /data1/INDEXES/200-current/index-206.fits
    COMMENT Index(14): /data1/INDEXES/200-current/index-205.fits
    COMMENT Index(15): /data1/INDEXES/200-current/index-204-11.fits
    COMMENT Index(16): /data1/INDEXES/200-current/index-204-10.fits
    COMMENT Index(17): /data1/INDEXES/200-current/index-204-09.fits
    COMMENT Index(18): /data1/INDEXES/200-current/index-204-08.fits
    COMMENT Index(19): /data1/INDEXES/200-current/index-204-07.fits
    COMMENT Index(20): /data1/INDEXES/200-current/index-204-06.fits
    COMMENT Index(21): /data1/INDEXES/200-current/index-204-05.fits
    COMMENT Index(22): /data1/INDEXES/200-current/index-204-04.fits
    COMMENT Index(23): /data1/INDEXES/200-current/index-204-03.fits
    COMMENT Index(24): /data1/INDEXES/200-current/index-204-02.fits
    COMMENT Index(25): /data1/INDEXES/200-current/index-204-01.fits
    COMMENT Index(26): /data1/INDEXES/200-current/index-204-00.fits
    COMMENT Index(27): /data1/INDEXES/200-current/index-203-11.fits
    COMMENT Index(28): /data1/INDEXES/200-current/index-203-10.fits
    COMMENT Index(29): /data1/INDEXES/200-current/index-203-09.fits
    COMMENT Index(30): /data1/INDEXES/200-current/index-203-08.fits
    COMMENT Index(31): /data1/INDEXES/200-current/index-203-07.fits
    COMMENT Index(32): /data1/INDEXES/200-current/index-203-06.fits
    COMMENT Index(33): /data1/INDEXES/200-current/index-203-05.fits
    COMMENT Index(34): /data1/INDEXES/200-current/index-203-04.fits
    COMMENT Index(35): /data1/INDEXES/200-current/index-203-03.fits
    COMMENT Index(36): /data1/INDEXES/200-current/index-203-02.fits
    COMMENT Index(37): /data1/INDEXES/200-current/index-203-01.fits
    COMMENT Index(38): /data1/INDEXES/200-current/index-203-00.fits
    COMMENT Index(39): /data1/INDEXES/200-current/index-202-11.fits
    COMMENT Index(40): /data1/INDEXES/200-current/index-202-10.fits
    COMMENT Index(41): /data1/INDEXES/200-current/index-202-09.fits
    COMMENT Index(42): /data1/INDEXES/200-current/index-202-08.fits
    COMMENT Index(43): /data1/INDEXES/200-current/index-202-07.fits
    COMMENT Index(44): /data1/INDEXES/200-current/index-202-06.fits
    COMMENT Index(45): /data1/INDEXES/200-current/index-202-05.fits
    COMMENT Index(46): /data1/INDEXES/200-current/index-202-04.fits
    COMMENT Index(47): /data1/INDEXES/200-current/index-202-03.fits
    COMMENT Index(48): /data1/INDEXES/200-current/index-202-02.fits
    COMMENT Index(49): /data1/INDEXES/200-current/index-202-01.fits
    COMMENT Index(50): /data1/INDEXES/200-current/index-202-00.fits
    COMMENT Index(51): /data1/INDEXES/200-current/index-201-11.fits
    COMMENT Index(52): /data1/INDEXES/200-current/index-201-10.fits
    COMMENT Index(53): /data1/INDEXES/200-current/index-201-09.fits
    COMMENT Index(54): /data1/INDEXES/200-current/index-201-08.fits
    COMMENT Index(55): /data1/INDEXES/200-current/index-201-07.fits
    COMMENT Index(56): /data1/INDEXES/200-current/index-201-06.fits
    COMMENT Index(57): /data1/INDEXES/200-current/index-201-05.fits
    COMMENT Index(58): /data1/INDEXES/200-current/index-201-04.fits
    COMMENT Index(59): /data1/INDEXES/200-current/index-201-03.fits
    COMMENT Index(60): /data1/INDEXES/200-current/index-201-02.fits
    COMMENT Index(61): /data1/INDEXES/200-current/index-201-01.fits
    COMMENT Index(62): /data1/INDEXES/200-current/index-201-00.fits
    COMMENT Index(63): /data1/INDEXES/200-current/index-200-11.fits
    COMMENT Index(64): /data1/INDEXES/200-current/index-200-10.fits
    COMMENT Index(65): /data1/INDEXES/200-current/index-200-09.fits
    COMMENT Index(66): /data1/INDEXES/200-current/index-200-08.fits
    COMMENT Index(67): /data1/INDEXES/200-current/index-200-07.fits
    COMMENT Index(68): /data1/INDEXES/200-current/index-200-06.fits
    COMMENT Index(69): /data1/INDEXES/200-current/index-200-05.fits
    COMMENT Index(70): /data1/INDEXES/200-current/index-200-04.fits
    COMMENT Index(71): /data1/INDEXES/200-current/index-200-03.fits
    COMMENT Index(72): /data1/INDEXES/200-current/index-200-02.fits
    COMMENT Index(73): /data1/INDEXES/200-current/index-200-01.fits
    COMMENT Index(74): /data1/INDEXES/200-current/index-200-00.fits
    COMMENT Index(75): /data1/INDEXES/4200/index-4200-21.fits
    COMMENT Index(76): /data1/INDEXES/4100/index-4119.fits
    COMMENT Index(77): /data1/INDEXES/4100/index-4118.fits
    COMMENT Index(78): /data1/INDEXES/4100/index-4117.fits
    COMMENT Index(79): /data1/INDEXES/4100/index-4116.fits
    COMMENT Index(80): /data1/INDEXES/4100/index-4115.fits
    COMMENT Index(81): /data1/INDEXES/4100/index-4114.fits
    COMMENT Index(82): /data1/INDEXES/4100/index-4113.fits
    COMMENT Index(83): /data1/INDEXES/4100/index-4112.fits
    COMMENT Index(84): /data1/INDEXES/4100/index-4111.fits
    COMMENT Index(85): /data1/INDEXES/4100/index-4110.fits
    COMMENT Index(86): /data1/INDEXES/4100/index-4109.fits
    COMMENT Index(87): /data1/INDEXES/4100/index-4108.fits
    COMMENT Index(88): /data1/INDEXES/4100/index-4107.fits
    COMMENT Field name: job.axy
    COMMENT Field scale lower: 0.351906 arcsec/pixel
    COMMENT Field scale upper: 633.431 arcsec/pixel
    COMMENT X col name: X
    COMMENT Y col name: Y
    COMMENT Start obj: 0
    COMMENT End obj: 0
    COMMENT Solved_in: (null)
    COMMENT Solved_out: (null)
    COMMENT Solvedserver: (null)
    COMMENT Parity: 2
    COMMENT Codetol: 0.01
    COMMENT Verify pixels: 1 pix
    COMMENT Maxquads: 0
    COMMENT Maxmatches: 0
    COMMENT Cpu limit: 600.000000 s
    COMMENT Time limit: 0 s
    COMMENT Total time limit: 0 s
    COMMENT Total CPU limit: 0.000000 s
    COMMENT Tweak: yes
    COMMENT Tweak AB order: 2
    COMMENT Tweak ABP order: 2
    COMMENT --
    COMMENT -- properties of the matching quad: --
    COMMENT index id: 204
    COMMENT index healpix: 7
    COMMENT index hpnside: 1
    COMMENT log odds: 240.394
    COMMENT odds: 2.52109e+104
    COMMENT quadno: 548352
    COMMENT stars: 609043,608950,609046,608956
    COMMENT field: 8,27,16,17
    COMMENT code error: 0.00591445
    COMMENT nmatch: 42
    COMMENT nconflict: 0
    COMMENT nfield: 279
    COMMENT nindex: 47
    COMMENT scale: 1.07344 arcsec/pix
    COMMENT parity: 1
    COMMENT quads tried: 627902
    COMMENT quads matched: 1517318
    COMMENT quads verified: 1437859
    COMMENT objs tried: 28
    COMMENT cpu time: 131.574
    COMMENT --
    COMMENT --End of WCS--
    COMMENT --(Put in by the new-wcs program)--

Ed Wiley_WEY
Ed Wiley_WEY's picture

Thanks, I can also use, but it is (1) slow and (2) I could only find out how to do it one image at a time. So I don't think this is a viable solution. SkyX is, I have used it before, all you have to do is parly the $$. This seems anthetical to VPhot and our member benefits.

What mystifies me is that almost identical images of the same FOV were handled just fine in VPhot.


pablotwa's picture
It's not a viable solution but

Ed you're right, is not a viable solution , I just wanted to see if there's something wrong with your sub and to get a pixel scale and there's nothing wrong with it. The Jpeg you posted here shows a Bayer Matrix like pattern but that maybe an artifact of the Jpeg compression scheme..and I'm sure that you setup a 1.07 arcsec/pixel  scale on pinpoint program.

That's all I can offer.

Good Luck!

Ed Wiley_WEY
Ed Wiley_WEY's picture
It's not a viable solution but

Thanks for the comments.


hambsch's picture
Change catalog



occasionally I have similar issues and then I change catalog to UCAC3 or so and it works.

You could use this catalog all the time.

I do not use VPHOT though due to my vast amount of data. I use LevesPhotometry instead, which need Pinpoint full version.


Ed Wiley_WEY
Ed Wiley_WEY's picture
SkyX is the solution if you have it

Following Eric's post, I used SkyX with its Image Link feature. As per Eric's email, SkyX has an abbreviated way of putting the plate solve into the fits file. All images were successfully plate solved and uploaded into VPhot with no problems. So, this s an easy solution if you happen to have some version of the Sky that will plate solve. I don't use SkyX for imaging, but it sure came in handy for plate solving when VPhot fails to arrive at a solution.

Thanks Eric!


Eric Dose
Eric Dose's picture
a typical night:

As brief follow-up: for last night's 214 FITS files (mostly Miras), ACP/PinPoint running my remote scope plate-solved 209 real-time (during ACP acquisition). Once downloaded from the remote site to my office PC, TheSkyX/ImageLink solved the other 5.  Most of my image batches go about like that. Inelegant workflow maybe, but it rescues some perfectly good observations and spares me headaches.

It probably does require that image fields be relatively square--limited skew and pincushion, etc. (I don't know whether or not VPhot even uses SIP or PinPoint distortion parameters in a FITS header.)

spp's picture
Astrometric catalog

Which astrometric catalog does VPhot's Pinpoint use?  If an image fails WCS using the default catalog does Pinpoint try a different catalog before giving up?


lmk's picture
Pinpoint issues

The BSM I operate, uses pinpoint for the plate solves, but due to various reasons, one of them being the CGEM mount RA/Dec axes likely are not quite 90 degrees!, it frequently fails to solve, and defaults to all-sky solving after a few fails. This is a big issue, since a lot of images are wasted and time lost with the failed solves. It seems that pinpoint is "weak" as far as locating itself, if things are not very close to the expected location, or the mount or image characteristics are less than "perfect"...


Ed Wiley_WEY
Ed Wiley_WEY's picture
Pinpoint Issues are not unique

Pinpoint, SkyX, PlateSolve2 (in SGP),, local (in SGP). -- they all fail on occasion. SkyX will usually work after a failure by centering on the target in the planetarium view. I have found that to be a strength of SkyX and its many add-ons. 



SGEO's picture
VPhot has a WCS workaround

When I get stuck with just a handful of images not solving I use the VPhot "Update WCS" tool:
- Identify one image that does solve and all the images that do not solve.
- On my local machine I align all the unsolved images on that one image known to be solvable.
- Re-upload the newly aligned images.
- On the image page check those images you just re uploaded and are still not solved as well as the one image that did solve and to which the others are aligned.
- Now click "Update WCS". VPhot will give the one good solution to all the other images.
Preset zingo!

Sorry I didn't offer this sooner but I was away at Stellafane. And the discussion offered in the thread looked productive!


VPhot has a WCS workaround

Hi George,  

Can you elaborate on your following comment?  Align as in stacking?

"-On my local machine I align all the unsolved images on that one image known to be solvable.
- Re-upload the newly aligned images."



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