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public:meetings:glowbi2008:tutorial_monday [2008-11-11 18:20] – James M Anderson | public:meetings:glowbi2008:tutorial_monday [2017-03-08 15:27] (current) – external edit 127.0.0.1 | ||
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This tutorial session is intended to get people familiar with the basic concepts of radio interferometry. | This tutorial session is intended to get people familiar with the basic concepts of radio interferometry. | ||
+ | |||
+ | |||
+ | History: | ||
+ | 2008 Nov ?? Initial version | ||
+ | 2010 NOv 14 Update for 31DEC10 AIPS | ||
====== Step 1 --- Figure Out What to Observe (Reduce) ====== | ====== Step 1 --- Figure Out What to Observe (Reduce) ====== | ||
Line 29: | Line 34: | ||
'' | '' | ||
+ | You should be able to download them from | ||
+ | [[ftp:// | ||
+ | [[ftp:// | ||
+ | |||
+ | While you are there, grab the new set of commands from | ||
+ | [[ftp:// | ||
====== Step 3 --- Start up AIPS ====== | ====== Step 3 --- Start up AIPS ====== | ||
Line 44: | Line 55: | ||
+ | '' | ||
+ | dowait=true\\ | ||
+ | dohist=1\\ | ||
+ | docrt=132\\ | ||
+ | dotv=1\\ | ||
+ | '' | ||
====== Step 4 --- Initial look at data ====== | ====== Step 4 --- Initial look at data ====== | ||
Line 54: | Line 71: | ||
'' | '' | ||
- | dowait=true\\ | ||
- | dohist=1\\ | ||
- | docrt=132\\ | ||
- | dotv=1\\ | ||
task ' | task ' | ||
- | default\\ | ||
datain = ' | datain = ' | ||
nfiles=0\\ | nfiles=0\\ | ||
ncount=2\\ | ncount=2\\ | ||
vlamode=' | vlamode=' | ||
+ | band ' | ||
doweight=10\\ | doweight=10\\ | ||
doconcat=true\\ | doconcat=true\\ | ||
Line 70: | Line 83: | ||
cparm(4)=28\\ | cparm(4)=28\\ | ||
cparm(8)=10./ | cparm(8)=10./ | ||
+ | dparm 0\\ | ||
+ | bparm 0\\ | ||
+ | timer 0\\ | ||
+ | calcode ' '\\ | ||
+ | clron\\ | ||
+ | outdisk 1\\ | ||
go\\ | go\\ | ||
'' | '' | ||
Line 75: | Line 94: | ||
This sets us up to read the data, sets the VLA mode to Solar, tells AIPS not to change the source if the position appears to be moving (which the Sun does), sets the shadowing limit to 28 meters, and sets the CL table interval to 10 seconds. | This sets us up to read the data, sets the VLA mode to Solar, tells AIPS not to change the source if the position appears to be moving (which the Sun does), sets the shadowing limit to 28 meters, and sets the CL table interval to 10 seconds. | ||
+ | ===== Header information ===== | ||
- | ===== LISTR --- scan listing ===== | ||
- | |||
- | First, let's check out which file we need. | ||
'' | '' | ||
- | pcat\\ | + | indisk 1\\ |
+ | pcat | ||
'' | '' | ||
- | |||
< | < | ||
AIPS 1: Catalog on disk 1 | AIPS 1: Catalog on disk 1 | ||
AIPS 1: Cat Usid Mapname | AIPS 1: Cat Usid Mapname | ||
- | AIPS 1: 1 100 19810926 | + | AIPS 1: 1 100 19810926 |
- | AIPS 1: 2 100 19810926 | + | |
- | AIPS 1: 3 100 19810926 | + | |
- | AIPS 1: | + | |
</ | </ | ||
'' | '' | ||
- | default listr\\ | + | getn 1\\ |
- | task ' | + | imhe |
- | indi 1\\ | + | |
- | getn 2\\ | + | |
- | optype ' | + | |
- | docrt=132\\ | + | |
- | go\\ | + | |
'' | '' | ||
+ | |||
+ | |||
< | < | ||
- | AIPS 1: Got(1) disk= 1 user= 100 type=UV 19810926.L BAND.1 | + | AIPS 1: Image=MULTI |
- | | + | AIPS 1: Telescope=VLA Receiver=VLA |
- | File = 19810926 | + | AIPS 1: Observer=GD |
- | Freq = | + | AIPS 1: Observ. date=26-SEP-1981 |
- | Scan summary listing | + | AIPS 1: # visibilities |
- | + | AIPS 1: Rand axes: UU-L-SIN VV-L-SIN WW-L-SIN BASELINE | |
- | Scan Source | + | AIPS 1: |
- | 1 1148-001 | + | AIPS 1: ---------------------------------------------------------------- |
- | 2 SUN : 0000 1 0/13:59:15 - 0/ | + | AIPS 1: Type Pixels |
- | 3 1148-001 | + | AIPS 1: COMPLEX |
- | 4 SUN : 0000 1 0/14:20:25 - | + | AIPS 1: STOKES |
- | 5 1148-001 | + | AIPS 1: FREQ 1 1.4461500E+09 |
- | 6 SUN : 0000 1 0/14:45:25 - 0/ | + | AIPS 1: IF 1 1.0000000E+00 |
- | 7 1148-001 : 0000 C 1 0/ | + | AIPS 1: RA 1 00 00 00.000 |
- | 8 SUN : 0000 | + | AIPS 1: DEC |
- | 9 1148-001 : 0000 C 1 0/15:32:55 - | + | AIPS 1: ---------------------------------------------------------------- |
- | 10 SUN : 0000 1 0/15:35:15 - | + | AIPS 1: Coordinate equinox |
- | 11 1148-001 | + | AIPS 1: Maximum version number of extension files of type HI is 1 |
- | 12 SUN : 0000 1 0/16:00:15 - 0/ | + | AIPS 1: Maximum version number of extension files of type AN is 1 |
- | 13 1148-001 : 0000 C 1 0/ | + | AIPS 1: Maximum version number of extension files of type NX is 1 |
- | 14 SUN : 0000 | + | AIPS 1: Maximum version number of extension files of type SU is 1 |
- | 15 1148-001 : 0000 C 1 0/ | + | AIPS 1: Maximum version number of extension files of type FQ is 1 |
- | 16 SUN : 0000 | + | AIPS 1: Maximum version number of extension files of type CL is 1 |
- | 17 1148-001 : 0000 C 1 0/ | + | AIPS 1: Maximum version number of extension files of type TY is 1 |
- | 18 1148-001 : 0000 C 1 0/ | + | AIPS 1: Maximum version number of extension files of type WX is 1 |
- | 19 SUN : 0000 | + | AIPS 1: Maximum version number of extension files of type OF is 1 |
- | 20 1148-001 : 0000 C 1 0/ | + | AIPS 1: Keyword |
- | 21 SUN : 0000 | + | AIPS 1: Keyword = ' |
- | 22 1148-001 : 0000 C 1 0/ | + | AIPS 1: Keyword = ' |
- | 23 SUN : 0000 | + | |
- | 24 1148-001 : 0000 C 1 0/ | + | |
- | 25 SUN : 0000 | + | |
- | 26 1148-001 : 0000 C 1 0/ | + | |
- | 27 SUN : 0000 1 0/18:54:45 - | + | |
- | 28 1148-001 | + | |
- | 29 SUN : 0000 1 0/19:19:35 - | + | |
- | 30 1148-001 | + | |
- | 31 SUN : 0000 1 | + | |
- | 32 1148-001 | + | |
- | 33 SUN : 0000 | + | |
- | 34 1148-001 | + | |
- | 35 SUN : 0000 1 | + | |
- | 36 1148-001 | + | |
- | 37 SUN : 0000 1 | + | |
- | 38 1148-001 | + | |
- | 39 SUN : 0000 1 0/21:24:15 - | + | |
- | 40 1148-001 | + | |
- | 41 SUN : 0000 1 | + | |
- | 42 1148-001 : 0000 C 1 0/ | + | |
- | 43 SUN : 0000 1 0/22:14:05 - 0/ | + | |
- | 44 1148-001 | + | |
- | 45 SUN : 0000 1 0/22:39:05 - | + | |
- | 46 1148-001 | + | |
- | 47 SUN : 0000 1 0/23:04:05 - | + | |
- | 48 1148-001 | + | |
- | 49 SUN : 0000 1 0/23:28:55 - | + | |
- | 50 1148-001 | + | |
- | 51 SUN : 0000 1 0/23:54:05 - | + | |
- | 52 SUN : 0000 1 1/00:07:25 - 1/ | + | |
- | 53 3C286 : 0000 B | + | |
- | + | ||
- | Source summary | + | |
- | Velocity type = ' | + | |
- | + | ||
- | ID Source | + | |
- | 1 1148-001 | + | |
- | 2 SUN : 0000 | + | |
- | 3 3C286 : 0000 | + | |
- | + | ||
- | ID Source | + | |
- | 1 All Sources | + | |
- | + | ||
- | Frequency Table summary | + | |
- | FQID IF# Freq(GHz) | + | |
- | | + | |
- | AIPS 1: Resumes | + | |
</ | </ | ||
+ | |||
+ | ===== LISTR --- scan listing ===== | ||
'' | '' | ||
- | getn 4\\ | + | task ' |
+ | indi 1\\ | ||
+ | getn 1\\ | ||
+ | optype ' | ||
+ | docrt=132\\ | ||
+ | flagver 0\\ | ||
+ | sources ' '\\ | ||
+ | stokes ' '\\ | ||
+ | docalib 0\\ | ||
+ | gainuse 1\\ | ||
+ | dopol -1\\ | ||
+ | dparm 0\\ | ||
go\\ | go\\ | ||
'' | '' | ||
< | < | ||
- | AIPS 1: Got(1) | + | |
- | vlb054 | + | File = 19810926 |
- | File = 19810926 | + | Freq = 1.446150006 GHz Ncor = 4 No. vis = |
- | Freq = 1.446150006 GHz Ncor = 4 No. vis = | + | |
Scan summary listing | Scan summary listing | ||
Scan Source | Scan Source | ||
- | 1 SUN : 0000 | + | |
- | 2 SUN : 0000 | + | 2 1148-001 |
- | 3 SUN : 0000 | + | 3 SUN : 0000 |
- | 4 SUN : 0000 | + | |
- | 5 SUN : 0000 | + | 5 1148-001 |
- | 6 SUN : 0000 | + | 6 SUN : 0000 |
- | 7 SUN : 0000 | + | |
- | 8 SUN : 0000 | + | 8 1148-001 |
- | 9 SUN : 0000 | + | 9 SUN : 0000 |
- | | + | 10 SUN : 0000 |
- | | + | 11 1148-001 |
- | | + | 12 SUN : 0000 |
- | | + | 13 SUN : 0000 |
- | | + | 14 1148-001 |
- | | + | 15 SUN : 0000 |
- | | + | 16 SUN : 0000 |
- | | + | 17 1148-001 |
- | | + | 18 SUN : 0000 |
- | | + | 19 SUN : 0000 |
- | | + | 20 1148-001 |
- | | + | 21 SUN : 0000 |
- | 22 SUN : 0000 | + | 22 SUN : 0000 |
- | 23 SUN : 0000 | + | 23 1148-001 |
- | | + | 24 SUN : 0000 |
- | | + | 25 SUN : 0000 |
+ | 26 1148-001 | ||
+ | 27 SUN : 0000 | ||
+ | 28 SUN : 0000 | ||
+ | 29 1148-001 | ||
+ | | ||
+ | 31 SUN : 0000 | ||
+ | 32 1148-001 | ||
+ | | ||
+ | 34 SUN : 0000 | ||
+ | 35 1148-001 | ||
+ | | ||
+ | 37 SUN : 0000 | ||
+ | 38 1148-001 | ||
+ | | ||
+ | 40 SUN : 0000 | ||
+ | | ||
+ | 42 SUN : 0000 | ||
+ | 43 SUN : 0000 | ||
+ | | ||
+ | 45 SUN : 0000 | ||
+ | 46 SUN : 0000 | ||
+ | | ||
+ | 48 SUN : 0000 | ||
+ | 49 SUN : 0000 | ||
+ | | ||
+ | 51 SUN : 0000 | ||
+ | 52 SUN : 0000 | ||
+ | | ||
+ | 54 SUN : 0000 | ||
+ | | ||
+ | | ||
+ | 57 SUN : 0000 | ||
+ | 58 SUN : 0000 | ||
+ | | ||
+ | 60 SUN : 0000 | ||
+ | 61 SUN : 0000 | ||
+ | | ||
+ | 63 SUN : 0000 | ||
+ | 64 SUN : 0000 | ||
+ | | ||
+ | 66 SUN : 0000 | ||
+ | 67 SUN : 0000 | ||
+ | | ||
+ | 69 SUN : 0000 | ||
+ | 70 SUN : 0000 | ||
+ | | ||
+ | 72 SUN : 0000 | ||
+ | 73 SUN : 0000 | ||
+ | | ||
+ | 75 SUN : 0000 | ||
+ | 76 SUN : 0000 | ||
+ | 77 3C286 : 0000 B 1 1/00:21:45 - | ||
Source summary | Source summary | ||
Line 228: | Line 256: | ||
ID Source | ID Source | ||
- | 1 SUN : 0000 | + | |
+ | | ||
+ | 3 3C286 : 0000 | ||
ID Source | ID Source | ||
Line 245: | Line 275: | ||
'' | '' | ||
- | getn 2\\ | ||
go prtan\\ | go prtan\\ | ||
'' | '' | ||
< | < | ||
- | | + | |
File=19810926 | File=19810926 | ||
Array= VLA Freq= 1446.150006 MHz | Array= VLA Freq= 1446.150006 MHz | ||
Line 402: | Line 431: | ||
AIPS 1: Resumes | AIPS 1: Resumes | ||
</ | </ | ||
+ | |||
+ | The really important part for you, the data reducer, is the antenna layout at the bottom. | ||
+ | |||
+ | |||
+ | |||
+ | ===== UVPLT ===== | ||
+ | |||
+ | Let's have a look at the information about the visibilities. | ||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | source ' | ||
+ | stokes ' | ||
+ | calcode ' '\\ | ||
+ | uvrange 0\\ | ||
+ | antennas 0\\ | ||
+ | basel 0\\ | ||
+ | xinc 1\\ | ||
+ | aparm 0\\ | ||
+ | bparm 0\\ | ||
+ | doweight 1\\ | ||
+ | refant 3\\ | ||
+ | do3col 1\\ | ||
+ | dotv 1\\ | ||
+ | tvinit\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | source ' | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | Warning: the next step will take a long time. You are free to skip this, and just look at the picture. | ||
+ | |||
+ | '' | ||
+ | source ' | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | {{: | ||
+ | |||
+ | |||
+ | '' | ||
+ | source ' | ||
+ | bparm 0 2\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | source ' | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | source ' | ||
+ | bparm 11 1\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | source ' | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | source ' | ||
+ | bparm 6 7\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | source ' | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | '' | ||
+ | source ' '\\ | ||
+ | bparm 11 15\\ | ||
+ | xinc 50\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | '' | ||
+ | bparm 11 18\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | ===== LISTR ===== | ||
+ | |||
+ | Now let's look at the raw visibility numbers. | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | xinc 1\\ | ||
+ | task ' | ||
+ | optype ' | ||
+ | source ' | ||
+ | stokes ' '\\ | ||
+ | bif 0\\ | ||
+ | eif 0\\ | ||
+ | flagver 0\\ | ||
+ | dparm 0\\ | ||
+ | antenna 3,0\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | < | ||
+ | | ||
+ | File = 19810926 | ||
+ | Freq= 1.446150006 GHz | ||
+ | Stokes = RR | ||
+ | |||
+ | |||
+ | Source=3C286 | ||
+ | Flux = 0.0000 Jy, Calcode = B , Freq = 1.446150006 GHz | ||
+ | Amplitudes, 1000 = 1.000 Jy, averging type = Vector | ||
+ | |||
+ | Baselines | ||
+ | | ||
+ | Amplitudes, 1000 = 10.000 Jy, averging type = Vector | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | AIPS 1: Resumes | ||
+ | </ | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | ===== Flagging ===== | ||
+ | |||
+ | |||
+ | Just enter these commands. | ||
+ | needed to be applied. | ||
+ | |||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | antenna 23,0\\ | ||
+ | basel 0\\ | ||
+ | timer 0\\ | ||
+ | aparm 0\\ | ||
+ | opcode ' | ||
+ | reason 'bad ant'\\ | ||
+ | dohist 1\\ | ||
+ | go\\ | ||
+ | antenna 26,0\\ | ||
+ | timer 0 18 29 0 0 20 7 20\\ | ||
+ | go\\ | ||
+ | timer 0 0 0 0 0 15 8 10\\ | ||
+ | go\\ | ||
+ | timer 0 21 48 30 0 22 37 10\\ | ||
+ | go\\ | ||
+ | antenna 25,0\\ | ||
+ | timer 0 22 38 20 1 0 21 50\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | ===== More LISTR, now on the phase calibrator ===== | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | optype ' | ||
+ | source ' | ||
+ | stokes ' '\\ | ||
+ | calcode ' '\\ | ||
+ | bif 0\\ | ||
+ | eif 0\\ | ||
+ | timer 0\\ | ||
+ | flagver 0\\ | ||
+ | dparm 0\\ | ||
+ | antenna 3,0\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | |||
+ | < | ||
+ | | ||
+ | File = 19810926 | ||
+ | Freq= 1.446150006 GHz | ||
+ | Stokes = RR | ||
+ | Applying flag table 1 | ||
+ | |||
+ | |||
+ | Source=1148-001 | ||
+ | Flux = 0.0000 Jy, Calcode = C , Freq = 1.446150006 GHz | ||
+ | Amplitudes, 1000 = 10.000 Jy, averging type = Vector | ||
+ | |||
+ | Baselines | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | |||
+ | Source=1148-001 | ||
+ | Flux = 0.0000 Jy, Calcode = C , Freq = 1.446150006 GHz | ||
+ | Amplitudes, 1000 = 10.000 Jy, averging type = Vector | ||
+ | |||
+ | Baselines | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | |||
+ | Source=1148-001 | ||
+ | Flux = 0.0000 Jy, Calcode = C , Freq = 1.446150006 GHz | ||
+ | Amplitudes, 1000 = 10.000 Jy, averging type = Vector | ||
+ | |||
+ | Baselines | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | |||
+ | Source=1148-001 | ||
+ | Flux = 0.0000 Jy, Calcode = C , Freq = 1.446150006 GHz | ||
+ | Amplitudes, 1000 = 10.000 Jy, averging type = Vector | ||
+ | |||
+ | Baselines | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | </ | ||
+ | |||
+ | |||
+ | '' | ||
+ | dparm 1,0\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | < | ||
+ | | ||
+ | File = 19810926 | ||
+ | Freq= 1.446150006 GHz | ||
+ | Stokes = RR | ||
+ | Applying flag table 1 | ||
+ | |||
+ | |||
+ | Source=1148-001 | ||
+ | Flux = 0.0000 Jy, Calcode = C , Freq = 1.446150006 GHz | ||
+ | Phase, 1000 = 1000.00 degrees, averging type = Vector | ||
+ | |||
+ | Baselines | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | |||
+ | Source=1148-001 | ||
+ | Flux = 0.0000 Jy, Calcode = C , Freq = 1.446150006 GHz | ||
+ | Phase, 1000 = 1000.00 degrees, averging type = Vector | ||
+ | |||
+ | Baselines | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | |||
+ | Source=1148-001 | ||
+ | Flux = 0.0000 Jy, Calcode = C , Freq = 1.446150006 GHz | ||
+ | Phase, 1000 = 1000.00 degrees, averging type = Vector | ||
+ | |||
+ | Baselines | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | |||
+ | Source=1148-001 | ||
+ | Flux = 0.0000 Jy, Calcode = C , Freq = 1.446150006 GHz | ||
+ | Phase, 1000 = 1000.00 degrees, averging type = Vector | ||
+ | |||
+ | Baselines | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | </ | ||
+ | |||
+ | ====== Calibration ====== | ||
+ | |||
+ | |||
+ | ===== SETJY ===== | ||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | source ' | ||
+ | optype ' | ||
+ | aparm 0\\ | ||
+ | aparm(2)=4\\ | ||
+ | zerosp 0\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | < | ||
+ | vlb054> SETJY1: Task SETJY (release of 31DEC10) begins | ||
+ | vlb054> SETJY1: **WARNING: OPCODE=CALC AND FREQID = -1 | ||
+ | vlb054> SETJY1: | ||
+ | vlb054> SETJY1: A source model for this calibrator is available | ||
+ | vlb054> SETJY1: Consult the help file for CALRD for assistance | ||
+ | vlb054> SETJY1: / Flux calculated using known spectrum | ||
+ | vlb054> SETJY1: BIF = 1 EIF = 1 /Range of IFs | ||
+ | vlb054> SETJY1: ' | ||
+ | vlb054> SETJY1: / Using (1995.2) VLA or Reynolds (1934-638) coefficients | ||
+ | vlb054> SETJY1: Appears to have ended successfully | ||
+ | vlb054> SETJY1: vlb054 | ||
+ | </ | ||
+ | |||
+ | ===== CALRD ===== | ||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | object ' | ||
+ | band ' | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | < | ||
+ | vlb054> CALRD1: Task CALRD (release of 31DEC08) begins | ||
+ | vlb054> CALRD1: Reading disk file AIPSTARS: | ||
+ | vlb054> CALRD1: Create 3C286_L | ||
+ | vlb054> CALRD1: Appears to have ended successfully | ||
+ | vlb054> CALRD1: vlb054 | ||
+ | </ | ||
+ | |||
+ | So it looks like the calibration data image was put into catalog entry number 2. | ||
+ | |||
+ | Let's have a look at it. | ||
+ | |||
+ | |||
+ | '' | ||
+ | getn 2\\ | ||
+ | tvinit\\ | ||
+ | tvlod\\ | ||
+ | tvfiddle\\ | ||
+ | '' | ||
+ | |||
+ | {{: | ||
+ | |||
+ | |||
+ | ===== UVFIX ===== | ||
+ | |||
+ | The sky positions (RA and Dec) were entered as coordinates of date, because the Sun is a moving object. | ||
+ | |||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | getn 1\\ | ||
+ | clron\\ | ||
+ | shift 0\\ | ||
+ | uvfixprm 0\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | UVFIX change in April means we have to regenerate NX table\\ | ||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | getn 3\\ | ||
+ | cparm 0\\ | ||
+ | cparm(3)= -1\\ | ||
+ | bparm 0\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | |||
+ | ===== CALIB ===== | ||
+ | |||
+ | First, we do the amplitude calibrator. | ||
+ | |||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | getn 3\\ | ||
+ | calsour ' | ||
+ | uvrange 0\\ | ||
+ | antennas 0\\ | ||
+ | timer 0\\ | ||
+ | refant 24\\ | ||
+ | weightit 1\\ | ||
+ | in2di 1\\ | ||
+ | get2n 2\\ | ||
+ | ncomp 0\\ | ||
+ | solmode ' | ||
+ | aparm 0\\ | ||
+ | aparm(6) 2\\ | ||
+ | minamper 10\\ | ||
+ | minphser 10\\ | ||
+ | docalib 1\\ | ||
+ | gainuse 1\\ | ||
+ | solint 30\\ | ||
+ | solsub 2\\ | ||
+ | cparm 0\\ | ||
+ | cparm(3) 10\\ | ||
+ | cparm(4) 10\\ | ||
+ | soltype ' '\\ | ||
+ | clrmsg\\ | ||
+ | go\\ | ||
+ | clrmsg\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | Next, the phase calibrator. | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | calsour ' | ||
+ | clr2n\\ | ||
+ | uvrange 1.5,0\\ | ||
+ | solint 0\\ | ||
+ | go\\ | ||
+ | clrmsg\\ | ||
+ | '' | ||
+ | |||
+ | ===== SNPLT ===== | ||
+ | |||
+ | Look at the amplitude calibrator results. | ||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | source ' '\\ | ||
+ | inver 1\\ | ||
+ | inext ' | ||
+ | stokes ' '\\ | ||
+ | optype ' | ||
+ | opcode ' | ||
+ | xinc 1\\ | ||
+ | nplots 9\\ | ||
+ | antenna 0\\ | ||
+ | timer 0\\ | ||
+ | tvinit\\ | ||
+ | dotv 1\\ | ||
+ | go\\ | ||
+ | optype ' | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | Look at the phase calibrator results. | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | inver 2\\ | ||
+ | optype ' | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | optype ' | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | {{: | ||
+ | |||
+ | |||
+ | ===== GETJY ===== | ||
+ | |||
+ | Now we need to transfer the amplitude calibration information from the amplitude calibrator to the phase calibrator. | ||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | sources ' | ||
+ | calsour ' | ||
+ | calcode ' '\\ | ||
+ | bif 0\\ | ||
+ | eif 0\\ | ||
+ | antenna 0\\ | ||
+ | timer 0\\ | ||
+ | snver 0\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | < | ||
+ | vlb054> GETJY1: Task GETJY (release of 31DEC08) begins | ||
+ | vlb054> GETJY1: | ||
+ | vlb054> GETJY1: 1148-001 | ||
+ | vlb054> GETJY1: Appears to have ended successfully | ||
+ | vlb054> GETJY1: vlb054 | ||
+ | </ | ||
+ | |||
+ | 2.9 Jy agrees relatively well with the rough value given by the VLA calibrator list. | ||
+ | |||
+ | < | ||
+ | 1150-003 | ||
+ | 1148-001 | ||
+ | ----------------------------------------------------- | ||
+ | BAND A B C D FLUX(Jy) | ||
+ | ===================================================== | ||
+ | | ||
+ | 6cm C P P P P 1.92 | ||
+ | 3.7cm X P P P P | ||
+ | 2cm U P P P P 1.40 | ||
+ | 1.3cm K S S S S | ||
+ | 0.7cm Q W W W W | ||
+ | </ | ||
+ | |||
+ | ===== Redo the CALIB calibration for the phase calibrator ===== | ||
+ | |||
+ | |||
+ | '' | ||
+ | inext ' | ||
+ | inver 2\\ | ||
+ | extdest\\ | ||
+ | tget calib\\ | ||
+ | go\\ | ||
+ | clrmsg\\ | ||
+ | '' | ||
+ | |||
+ | ===== Apply the calibration to all sources, both amplitude and phase ===== | ||
+ | |||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | getn 3\\ | ||
+ | sources ' '\\ | ||
+ | calsour ' | ||
+ | calcode ' '\\ | ||
+ | opcode ' | ||
+ | gainver 1\\ | ||
+ | gainuse 2\\ | ||
+ | refant 24\\ | ||
+ | bparm 0\\ | ||
+ | interpol ' | ||
+ | timer 0\\ | ||
+ | antenna 0\\ | ||
+ | doblank 1\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | ===== Check the calibration results ===== | ||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | source ' '\\ | ||
+ | inver 2\\ | ||
+ | inext ' | ||
+ | stokes ' '\\ | ||
+ | optype ' | ||
+ | opcode ' | ||
+ | xinc 1\\ | ||
+ | nplots 9\\ | ||
+ | antenna 0\\ | ||
+ | timer 0\\ | ||
+ | tvinit\\ | ||
+ | dotv 1\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | {{: | ||
+ | |||
+ | |||
+ | '' | ||
+ | optype ' | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | ====== Test Imaging ====== | ||
+ | |||
+ | ===== Amplitude Calibrator ===== | ||
+ | |||
+ | |||
+ | Ok, let's start with a few test images. | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | getn 3\\ | ||
+ | source ' | ||
+ | uvrange 0\\ | ||
+ | docalib 1\\ | ||
+ | gainuse 2\\ | ||
+ | stokes ' | ||
+ | cellsize 10,10\\ | ||
+ | imsize 512,512\\ | ||
+ | antenna 0\\ | ||
+ | niter 10000\\ | ||
+ | overlap 1\\ | ||
+ | DO3DIMAG 1\\ | ||
+ | rashift 1800.00,0\\ | ||
+ | decshift -920.00,0\\ | ||
+ | go\\ | ||
+ | clrmsg\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | After you have cleaned it a bit, this is what it looks like. | ||
+ | |||
+ | {{: | ||
+ | |||
+ | |||
+ | And this is the point spread function of the actual observations (called the dirty beam). | ||
+ | |||
+ | |||
+ | '' | ||
+ | getn 5\\ | ||
+ | tvinit\\ | ||
+ | tvlod\\ | ||
+ | tvfiddle\\ | ||
+ | '' | ||
+ | |||
+ | {{: | ||
+ | |||
+ | ===== Phase Calibrator ===== | ||
+ | |||
+ | Ok, clean up after ourselves | ||
+ | |||
+ | |||
+ | '' | ||
+ | getn 5;zap\\ | ||
+ | getn 6;zap\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | Now do the imaging and light cleaning | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | tget imagr\\ | ||
+ | source ' | ||
+ | rashift 0\\ | ||
+ | decshift 0\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | Note that in this image, there is a lot of large-scale junk. Why? | ||
+ | |||
+ | |||
+ | And here is the dirty beam. Notice how the dirty beam looks like the initial image of the phase calibrator before you began to clean it. Why? | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | getn 5\\ | ||
+ | tvinit\\ | ||
+ | tvlod\\ | ||
+ | tvfiddle\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | ====== Imaging the Sun ====== | ||
+ | |||
+ | |||
+ | Ok, to do the best job, we need to separate the Sun data from the rest of the dataset. | ||
+ | |||
+ | '' | ||
+ | getn 5;zap\\ | ||
+ | getn 6;zap\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | |||
+ | ===== SPLIT ===== | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | getn 3\\ | ||
+ | source ' | ||
+ | timer 0\\ | ||
+ | stokes ' '\\ | ||
+ | aparm 0\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | ===== IMAGR ===== | ||
+ | |||
+ | |||
+ | Now do an initial imaging and cleaning step. | ||
+ | |||
+ | |||
+ | '' | ||
+ | tget imagr\\ | ||
+ | getn 4\\ | ||
+ | source ' '\\ | ||
+ | docalib 0\\ | ||
+ | gainuse 1\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | Here are some of the stages of my cleaning. | ||
+ | |||
+ | {{: | ||
+ | {{: | ||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | ===== Self-Calibration ===== | ||
+ | |||
+ | Ok, let's do some self-calibration. | ||
+ | |||
+ | We run exactly the same calibration software, it exactly the same manner. | ||
+ | |||
+ | |||
+ | '' | ||
+ | tget calib\\ | ||
+ | getn 4\\ | ||
+ | get2n 7\\ | ||
+ | solint 30/60\\ | ||
+ | solmode ' | ||
+ | docalib 0\\ | ||
+ | uvrange 0.5,0\\ | ||
+ | calsour ' '\\ | ||
+ | inver 0\\ | ||
+ | snver 0\\ | ||
+ | go\\ | ||
+ | clrmsg\\ | ||
+ | '' | ||
+ | |||
+ | ==== Check the results ==== | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | inext ' | ||
+ | inver 1\\ | ||
+ | stokes ' '\\ | ||
+ | optype ' | ||
+ | tvinit\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | |||
+ | Note some of the really large phase deviations! | ||
+ | |||
+ | ===== Image again, using the new calibration ===== | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | getn 5;zap\\ | ||
+ | getn 6;zap\\ | ||
+ | getn 7;zap\\ | ||
+ | tget imagr\\ | ||
+ | docalib 1\\ | ||
+ | gainuse 1\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | {{: | ||
+ | |||
+ | This one is a bit better. | ||
+ | |||
+ | |||
+ | |||
+ | ===== More Self-Calibration ===== | ||
+ | But we can do more. Now let's do both amplitude and phase calibration. | ||
+ | |||
+ | ==== Phase Self-Cal ==== | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | tget calib\\ | ||
+ | getn 4\\ | ||
+ | get2n 7\\ | ||
+ | solint 20/60\\ | ||
+ | solmode ' | ||
+ | docalib 0\\ | ||
+ | uvrange 0.5,0\\ | ||
+ | calsour ' '\\ | ||
+ | inver 0\\ | ||
+ | snver 0\\ | ||
+ | go\\ | ||
+ | clrmsg\\ | ||
+ | '' | ||
+ | ==== Check ==== | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | inext ' | ||
+ | inver 2\\ | ||
+ | stokes ' '\\ | ||
+ | optype ' | ||
+ | tvinit\\ | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | ==== Amplitude Self-Cal ==== | ||
+ | |||
+ | Doing both phase and amplitude calibration requires far more from the data S/N. It is best to have a longer time interval for amplitude calibration. | ||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | tget calib\\ | ||
+ | getn 5\\ | ||
+ | solint 20\\ | ||
+ | solmode ' | ||
+ | cparm(2) 1\\ | ||
+ | go\\ | ||
+ | clrmsg\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | ==== Check ==== | ||
+ | |||
+ | |||
+ | '' | ||
+ | task ' | ||
+ | inext ' | ||
+ | inver 1\\ | ||
+ | stokes ' '\\ | ||
+ | optype ' | ||
+ | tvinit\\ | ||
+ | go\\ | ||
+ | optype ' | ||
+ | go\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | ==== Cleanup ==== | ||
+ | |||
+ | Clean up the files. | ||
+ | |||
+ | |||
+ | '' | ||
+ | getn 6;zap\\ | ||
+ | getn 7;zap\\ | ||
+ | getn 8;zap\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | ===== Final Imaging ===== | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | '' | ||
+ | tget imagr\\ | ||
+ | getn 5\\ | ||
+ | docalib 1\\ | ||
+ | gainuse 1\\ | ||
+ | '' | ||
+ | |||
+ | {{: | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | ====== Discussion ====== | ||
+ | |||
+ | What have you learned? | ||
+ | |||
+ | Does your image look like this image? | ||
+ | {{http:// | ||
+ | |||
+ | What is different? | ||
+ | |||
+ | Have a look at http:// | ||