Rotation measurment problem

[Rami zainal]

Hi all,

My name is Rami, I am PhD student at Western Sydney University. I am work on some SNR, produce polarisation images and rotation measurement.

I have problem with task (imrm), it gave me Fortran runtime error.
I split 5.5 GHz into four frequencies, I produced images for stokes (I, q, u, v) for four frequencies, and then used the task (impol) to produce position angle (pa) and the error of position angle (pa_e).

Task: imrm
in = n103b.6268.pa1,n103b.5756.pa1,n103b.5244.pa1,n103b.4732.pa1
inerr = n103b.6268.pa_e1,n103b.5756.pa_e1,n103b.5244.pa_e1,n103b.4732.pa_e1
rmi =
rm = rm1,rm1_e
pa0 = pa0,pa0_e
qcut =
errcut =
rmcut =
pacut =
device = /xs
nxy =
csize =
options =
imrm% go

imrm: Revision 1.9, 2011/10/06 07:18:56 UTC

### Warning: It is advised that some error-based blanking be used.

At line 901 of file /nfs/atapplic/miriad/linux64/tmp/imrm.f
Fortran runtime error: Expected INTEGER for item 4 in formatted transfer, got CHARACTER
('Axis ',i1,' differs in length for ',a,' & ',a)
^

Thank you for help

Cheers,
Rami

[Mark.Wieringa]

Hi Rami,

welcome to the forum!

I've had a look at the code and there is indeed a problem at that line. I've fixed that and a new version will be built tonight.
Depending on how you update Miriad, you can either do a mirsync tomorrow, or wait till Friday for a new tar file download.

However, you will only run into this error if the axes in your input images differ. So the first thing to do is check that all
your input images are the same size. You could use prthd for this.

Cheers,

Mark

[Rami zainal]

Thank you Mark for quick reply... the positions angle look diffident see below:

prthd: Revision 1.10, 2012/03/02 06:13:02 UTC

****************************************************************
Filename: n103b.6268.pa1
Telescope: ATCA
Object: 120-n_103b Observer: PM
Image type: position_angle
Map flux units: DEGREES
Beam Size: 2.00 by 2.00 arcsec.
Position angle: 0.0 degrees.
This image has 3 axes.
----------------------------------------------------------------
Type Pixels Coord Value at Pixel Coord Incr Units
RA---NCP 3478 05:08:59.416 1740.00 -4.021471E-01 arcsec
DEC--NCP 3478 -68:43:35.170 1740.00 4.021471E-01 arcsec
FREQ-LSR 1 6.215845E+00 1.00 1.000000E-03 GHz
----------------------------------------------------------------
Average time of observation: 17AUG17:00:05:38.8
Equinox: J2000.0
Doppler reference frame: TOPOCENT
Observatory radial velocity: 17.31 km/s
Number of iterations: 2000
Mask item is present ... some data are blanked
History item is present
miriad% prthd in=n103b.4732.pa1

prthd: Revision 1.10, 2012/03/02 06:13:02 UTC

****************************************************************
Filename: n103b.4732.pa1
Telescope: ATCA
Object: 120-n_103b Observer: PM
Image type: position_angle
Map flux units: DEGREES
Beam Size: 2.00 by 2.00 arcsec.
Position angle: 0.0 degrees.
This image has 3 axes.
----------------------------------------------------------------
Type Pixels Coord Value at Pixel Coord Incr Units
RA---NCP 3511 05:08:59.416 1756.00 -5.179448E-01 arcsec
DEC--NCP 3511 -68:43:35.170 1756.00 5.179448E-01 arcsec
FREQ-LSR 1 4.781480E+00 1.00 1.000000E-03 GHz
----------------------------------------------------------------
Average time of observation: 17AUG17:00:05:38.8
Equinox: J2000.0
Doppler reference frame: TOPOCENT
Observatory radial velocity: 17.31 km/s
Number of iterations: 2000
Mask item is present ... some data are blanked
History item is present
miriad% prthd in=n103b.5244.pa1

prthd: Revision 1.10, 2012/03/02 06:13:02 UTC

****************************************************************
Filename: n103b.5244.pa1
Telescope: ATCA
Object: 120-n_103b Observer: PM
Image type: position_angle
Map flux units: DEGREES
Beam Size: 2.00 by 2.00 arcsec.
Position angle: 0.0 degrees.
This image has 3 axes.
----------------------------------------------------------------
Type Pixels Coord Value at Pixel Coord Incr Units
RA---NCP 3531 05:08:59.416 1766.00 -4.697201E-01 arcsec
DEC--NCP 3531 -68:43:35.170 1766.00 4.697201E-01 arcsec
FREQ-LSR 1 5.242167E+00 1.00 1.000000E-03 GHz
----------------------------------------------------------------
Average time of observation: 17AUG17:00:05:38.8
Equinox: J2000.0
Doppler reference frame: TOPOCENT
Observatory radial velocity: 17.31 km/s
Number of iterations: 2000
Mask item is present ... some data are blanked
History item is present
miriad% prthd in=n103b.5756.pa1

prthd: Revision 1.10, 2012/03/02 06:13:02 UTC

****************************************************************
Filename: n103b.5756.pa1
Telescope: ATCA
Object: 120-n_103b Observer: PM
Image type: position_angle
Map flux units: DEGREES
Beam Size: 2.00 by 2.00 arcsec.
Position angle: 0.0 degrees.
This image has 3 axes.
----------------------------------------------------------------
Type Pixels Coord Value at Pixel Coord Incr Units
RA---NCP 3515 05:08:59.416 1758.00 -4.297107E-01 arcsec
DEC--NCP 3515 -68:43:35.170 1758.00 4.297107E-01 arcsec
FREQ-LSR 1 5.755387E+00 1.00 1.000000E-03 GHz
----------------------------------------------------------------
Average time of observation: 17AUG17:00:05:38.8
Equinox: J2000.0
Doppler reference frame: TOPOCENT
Observatory radial velocity: 17.31 km/s
Number of iterations: 2000
Mask item is present ... some data are blanked
History item is present

in applied task (regrid) to make them the same size.
I applied the (imrm) again, it worked, but with diffident error

Task: imrm
in = n103b.6268.pa1,n103b.5756.pa.regrided,n103b.5244.pa.regrided,n103b.4732.pa.regrided
inerr = n103b.6268.pa_e1/,n103b.5756.pa_e.regrided/,n103b.5244.pa_e.regrided/,n103b.4732.pa_e.regrided/
rmi =
rm = rm1,rm1_e
pa0 = pa0,pa0_e
qcut =
errcut =
rmcut =
pacut =
device = /xs
nxy =
csize =
options =
imrm% go

imrm: Revision 1.9, 2011/10/06 07:18:56 UTC

### Warning: It is advised that some error-based blanking be used.


Found frequency 6.2162 GHz
Found frequency 6.2162 GHz
Found frequency 6.2162 GHz
Found frequency 6.2162 GHz
### Warning: There are degenerate frequencies amongst the PA images
### Warning: There are degenerate frequencies amongst the PA images
### Warning: There are degenerate frequencies amongst the PA images
### Warning: There are degenerate frequencies amongst the PA images
### Warning: There are degenerate frequencies amongst the PA images
### Warning: There are degenerate frequencies amongst the PA images
### Fatal Error: No convergence in GCF

[Mark.Wieringa]

Hi Rami,

I think what may have happened is that you forgot to specify axes=1,2 in regrid, which means it regridded all axes including the frequency one.
This means all images have the same frequency in the header now and imrm doesn't like that.
So try again and make sure the first two axes are the same for all images, but the frequencies are left untouched.

Cheers,

Mark

[Rami zainal]

Thank you Mark. It works. appreciated.

Cheers,
Rami