Ionosphere calibration

Ionosphere calibration


Compilation options

Logged on 09/30/2009 12:33:03 PM

MS:VLAAA4h_LF Sky model - grid; 5 sources in each direction; 30 arcmin; 1Jy flux Z jones - Rotate ionosphere; sine_tid_model TEC model; TEC=10; Relative amplitudes=0.1; X size=100Km; X speed=150Km/h; Y size=120Km; Y speed=200 Km/h; no central phase correction

Data products

.tdl.conf


Simulate MS

Logged on 09/30/2009 12:41:09 PM

Column: DATA Time slots:100 Image shows phase fluctuations

Data products

iono_phases.png

iono_phases.png


Make dirty image

Logged on 09/30/2009 12:43:45 PM

64 channels I stokes 512 pixels, 150 arcmin image

Data products

VLAAA4h_LF.MS.DATA.channel.64ch.fits (header)

64x1x512x512 FITS cube, 4 planes are given below.

0-full.png

Image plane #0.

data range:-0.0457696,0.0466941
mean:0.00209288
sigma:0.0117004
clipping:95%
clip range:-0.0228342,0.0233073
1-full.png

Image plane #1.

data range:-0.0480625,0.0615764
mean:0.00126581
sigma:0.0112183
clipping:95%
clip range:-0.0217234,0.0224962
2-full.png

Image plane #2.

data range:-0.0435119,0.0525258
mean:0.00125629
sigma:0.0113486
clipping:95%
clip range:-0.0206279,0.0239208
3-full.png

Image plane #3.

data range:-0.059445,0.0556331
mean:0.00147387
sigma:0.0129706
clipping:95%
clip range:-0.0259555,0.0251778

Higher freq. dirty image

Logged on 09/30/2009 12:51:09 PM

channel 35

Data products

channel35.ppm

channel35.ppm


Correct for ionosphere central phase

Logged on 09/30/2009 03:42:33 PM

set correct for central phase and compile Image shows central phase is now corrected...

Data products

.tdl.conf

iono_phases_corrected.png

iono_phases_corrected.png


Corrected fits data

Logged on 09/30/2009 03:44:57 PM

Central point source looks much better. Channel 35 also shown.

Data products

VLAAA4h_LF.MS.DATA.channel.64ch.fits (header)

64x1x512x512 FITS cube, 4 planes are given below.

0-full.png

Image plane #0.

data range:-0.0861085,0.470662
mean:0.0049048
sigma:0.0306848
clipping:95%
clip range:-0.0665345,0.0579777
1-full.png

Image plane #1.

data range:-0.0818528,0.486475
mean:0.00352996
sigma:0.0305794
clipping:95%
clip range:-0.0707527,0.0618941
2-full.png

Image plane #2.

data range:-0.0913039,0.489727
mean:0.00401065
sigma:0.0307535
clipping:95%
clip range:-0.0691748,0.0607628
3-full.png

Image plane #3.

data range:-0.0918201,0.508197
mean:0.00391652
sigma:0.0352033
clipping:95%
clip range:-0.0836167,0.0740051
channel35_corrected.ppm

channel35_corrected.ppm


Subtract sky model

Logged on 09/30/2009 03:51:49 PM

Choose subtract from MS on TDL options simulation mode. Uncheck the Z jones. Final image shows the residuals. See also channel 35 (enhanced with histogram: -60 +60 mJy/beam). Thats it!

Data products

.tdl.conf

VLAAA4h_LF.MS.CORRECTED_DATA.channel.64ch.fits (header)

64x1x512x512 FITS cube, 4 planes are given below.

0-full.png

Image plane #0.

data range:-0.385749,0.12203
mean:0.000273911
sigma:0.0276431
clipping:95%
clip range:-0.0445853,0.0531027
1-full.png

Image plane #1.

data range:-0.413309,0.138776
mean:-7.21246e-05
sigma:0.0274623
clipping:95%
clip range:-0.0483073,0.0492781
2-full.png

Image plane #2.

data range:-0.423664,0.144581
mean:0.000226661
sigma:0.0253712
clipping:95%
clip range:-0.044094,0.0452493
3-full.png

Image plane #3.

data range:-0.363752,0.1416
mean:0.000167094
sigma:0.0220457
clipping:95%
clip range:-0.0414913,0.0389506
channel35_residuals.ppm

channel35_residuals.ppm


This log was generated by PURR version 1.0.