[daip] cross-correlation of theoretical images
Amy Mioduszewski
amiodusz at nrao.edu
Tue Apr 17 15:19:08 EDT 2012
Juan-Carlos,
So sorry, now I am on travel and cannot help until I get back Friday.
Amy
> Dear Amy,
>
> Initially the model was just an image, and hence I thought it would be OK
> to set any
> parameters on it. For example, I do not consider essential to have the
> right RA, DEC,
> and parameters for beam size can also be altered without loss of
> generality, as far as I
> understand. I used the following to make the maps match:
> - OGEOM for pixels and peak pixel
> - PUTHEAD for map type, coord incr, rotat, flux units
> (about conv size and flux units, recall previous question regarding
> Jy/pixel vs Jy/beam)
> Am I doing any wrong assumption here when I think I can manipulate the
> theoretical image
> to match the observed one without loss of generality?
>
> I have tried OHGEO. Here's a sample header for the theoretical image
> modified by OHGEO:
>
> AIPS 1: Got(1) disk= 2 user=3000 type=MA MODGLJET .OHGEO.2
> AIPS 1: Image= (MA) Filename=MODGLJET .OHGEO . 2
> AIPS 1: Telescope=VLBI Receiver=VLBI
> AIPS 1: Observer= User #= 3000
> AIPS 1: Observ. date=05-OCT-2007 Map date=16-APR-2012
> AIPS 1: Pixel type: FLOATING Magic value blanking
> AIPS 1: Minimum= 1.00000002E+20 Maximum=-1.00000002E+20 JY/BEAM
> AIPS 1: ----------------------------------------------------------------
> AIPS 1: Type Pixels Coord value at Pixel Coord incr Rotat
> AIPS 1: RA---SIN 102 00 00 00.000 51.00 -0.000002 0.00
> AIPS 1: DEC--SIN 102 12 23 59.999 51.00 0.000002 0.00
> AIPS 1: ----------------------------------------------------------------
> AIPS 1: Coordinate equinox 2000.00
> AIPS 1: Map type=NORMAL Number of iterations= 100
> AIPS 1: Conv size= 0.00002 X 0.00002 Position angle= -23.93
> AIPS 1: Observed RA 17 45 40.041 DEC -29 00 28.12
> AIPS 1: Maximum version number of extension files of type HI is 1
>
> Both if I use the observed map as a template to interpolate the
> theoretical one or
> vice-versa, the parameters in the header seem to adequately match, but the
> flux behaves
> funny. I have tried in both initial files and files whose header I had
> already modified
> and the problem still remains.
>
> I have also tried HGEOM but the task dies giving the following message:
>
> localh> HGEOM1: Task HGEOM (release of 31DEC11) begins
> localh> HGEOM1: You are using a non-standard program
> localh> HGEOM1: I WANT TO DIE BUT I CANNOT
> localh> HGEOM1: Create ICLJETGL .HGEOM . 1 (MA) on disk 2 cno 52
> localh> HGEOM1: Using 12271 words of buffer
> localh> HGEOM1: Begin computing coordinate tables
> localh> HGEOM1: Begin computing output image
> localh> HGEOM1: ***** ALL OUTPUT PIXELS BLANKED *****
> localh> HGEOM1: SUBROUTINE MAPIO RETURNED ERROR 16 AT 165
> localh> HGEOM1: ILLEGAL WINDOW SPECIFICATION
> localh> HGEOM1: DISK 2 SLOT 52 USER 3000 (MA)FILE: ICLJETGL.HGEOM.1
> localh> HGEOM1: Destroyed MA image file: catno= 52 disk= 2
> localh> HGEOM1: Purports to die of UNNATURAL causes
> localh> HGEOM1: localhost 31DEC11 TST: Cpu= 0.0 Real= 0
>
> Still receiving same error even after specifying
> BLC=1,TRC=120,IMSIZE=120,120 in the
> inputs and/or using REMAG files to ensure no blanked pixels are in the
> image. My guess,
> given the two results with HGEOM and OHGEO, is that the headers are
> properly
> interpolated but, for some reason, the output is blanked in both cases,
> giving the error
> above in the case of HGEOM and the strange flux behaviour in the case of
> OHGEO.
>
> Is it possible that the flux is ill-defined due to the previous issue
> (convolution and
> Jy/pixel to Jy/beam), thus leading to this problem?
>
> CONVL seems to be able to cross-correlate the two maps now but, due to
> this issue with
> the flux, the result obviously does not make any sense.
>
> Thank you very much
>
> JC
>
>
> ---------- Original Message -----------
> From:Amy Mioduszewski <amiodusz at nrao.edu>
> To:Juan-Carlos Algaba-Marcos <algaba at asiaa.sinica.edu.tw>
> Cc:daip at nrao.edu
> Sent:Mon, 16 Apr 2012 09:24:17 -0600
> Subject:Re: [daip] cross-correlation of theoretical images
>
>> Dear Juan-Carlos,
>>
>> I'm sorry, our primary expert is away. Did the original pair of images
>> have
>> the same geometries? Or did you just force them to be the same? To
>> make the
>> image geometries consistent I would recommend using OHGEO.
>>
>> Also I notice that the RAs are different.
>>
>> Amy
>>
>> Juan-Carlos Algaba-Marcos wrote:
>> > To whom it may concern,
>> >
>> > I am lately working on task CONVL with theoretical and observed
>> images. Currently I want
>> > to obtain the cross-correlation of a theoretical model and the
>> corresponding synthesized
>> > 'observed' one. (OPCODE='IMAC') However, when I try to do so I obtain
>> the following
> error:
>> >
>> > localh> CONVL1: CONFIL: UNEQUAL SPACINGS IN TWO MAPS
>> > localh> CONVL1: IMAGE= 0.0000 0.0000 CONV. FN= 0.0000
>> 0.0000
>> > localh> CONVL1: Destroyed MA image file: catno= 39 disk= 2
>> > localh> CONVL1: Purports to die of UNNATURAL causes
>> > localh> CONVL1: localhost 31DEC11 TST: Cpu= 0.0 Real=
>> 0
>> >
>> > As the first image is a model, I have removed the blanks with task
>> REMAG and adjusted
>> > all values to match the observed image with PUTHEAD. Here are the
>> headers of both input
>> > images:
>> >
>> > MODEL
>> >
>> > AIPS 1: Image= (MA) Filename=MODGLJET .REMAG . 3
>> > AIPS 1: Telescope=VLBI Receiver=VLBI
>> > AIPS 1: Observer= User #= 3000
>> > AIPS 1: Observ. date=05-OCT-2007 Map date=16-APR-2012
>> > AIPS 1: Minimum= 1.71167770E-07 Maximum= 3.32765914E-02 JY/BEAM
>> > AIPS 1:
>> ----------------------------------------------------------------
>> > AIPS 1: Type Pixels Coord value at Pixel Coord incr
>> Rotat
>> > AIPS 1: RA---SIN 102 17 45 40.041 51.00 -0.000002
>> 0.00
>> > AIPS 1: DEC--SIN 102 -29 00 28.118 51.00 0.000002
>> 0.00
>> > AIPS 1:
>> ----------------------------------------------------------------
>> > AIPS 1: Coordinate equinox 2000.00
>> > AIPS 1: Map type=NORMAL Number of iterations= 100
>> > AIPS 1: Conv size= 0.00002 X 0.00002 Position angle= -23.93
>> > AIPS 1: Maximum version number of extension files of type HI is 1
>> >
>> >
>> > OBSERVED:
>> >
>> > AIPS 1: Image= (MA) Filename=ICL JETGL .REMAG . 2
>> > AIPS 1: Telescope= Receiver=
>> > AIPS 1: Observer= User #= 3000
>> > AIPS 1: Observ. date=01-JAN-2000 Map date=16-APR-2012
>> > AIPS 1: Minimum=-1.13594451E-03 Maximum= 4.81160544E-02 JY/BEAM
>> > AIPS 1:
>> ----------------------------------------------------------------
>> > AIPS 1: Type Pixels Coord value at Pixel Coord incr
>> Rotat
>> > AIPS 1: RA---SIN 102 00 00 00.000 51.00 -0.000002
>> 0.00
>> > AIPS 1: DEC--SIN 102 12 23 59.999 51.00 0.000002
>> 0.00
>> > AIPS 1: FREQ 1 2.3000000E+11 1.00 1.0000000E+09
>> 0.00
>> > AIPS 1: STOKES 1 -1.0000000E+00 1.00 1.0000000E+00
>> 0.00
>> > AIPS 1:
>> ----------------------------------------------------------------
>> > AIPS 1: Coordinate equinox 2000.00
>> > AIPS 1: Map type=NORMAL Number of iterations= 1913
>> > AIPS 1: Conv size= 0.00002 X 0.00002 Position angle= -23.93
>> > AIPS 1: Maximum version number of extension files of type HI is 1
>> > AIPS 1: Maximum version number of extension files of type CC is 1
>> > AIPS 1: Keyword = 'MAXABSU ' value = 2.242303E+10
>> > AIPS 1: Keyword = 'MAXBLINE' value = 2.242303E+10
>> >
>> > I have modified the map type (hence, iterations), conv size, coord
>> increase, size of the
>> > model. However, after matching all these, I still keep receiving the
>> same error when
>> > trying to cross-correlate.
>> >
>> > I have found the same problem with OPCODE 'IMAG', but everything runs
>> fine when I use
>> > OPCODE 'DGAU' or I try to autocorrelate the same image. Where can the
>> problem be?
>> >
>> > Thank you very much
>> >
>> > _______________________________________________
>> > Daip mailing list
>> > Daip at listmgr.cv.nrao.edu
>> > http://listmgr.cv.nrao.edu/mailman/listinfo/daip
>> >
> ------- End of Original Message -------
>
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