Calibration
Data calibration is a critical step in the data analysis process. Commonalibration ensures that systematic, instrumental, or environmental effects that occur during observations are accounted for and corrected to maintain the integrity of the data. Ensuring that measurements are appropriately adjusted, calibration safeguards against inaccuracies that could render the data unusable for scientific analysis, ultimately refining the precision and accuracy of the measurements obtained.
The process of data calibration involves several key steps which vary according to the frequency of observation.
The HartRAO 26m antenna currently monitors the following calibrators
IVS |
J2000 |
RA |
Dec |
Freq |
Freq |
Obs./Central |
---|---|---|---|---|---|---|
name |
name |
[deg] |
[deg] |
band |
range |
freqs[GHz] |
Jupiter |
K |
20.346, 20.971, 22, 23.121 |
||||
0433+296 |
3C123 |
69.26 |
29.67 |
1.668, 2.28, 4.874, 6.7, 8.4, 12.2 |
||
0134+329 (J0137+3309) |
3C48 |
24.42 |
33.15 |
2.28, 4.874, 8.4 |
||
0624-058 |
3C161 |
96.79 |
-5.88 |
2.28, 4.874, 8.4 |
||
1328+307 (J1331+3030) |
3C286 |
202.78 |
30.50 |
4.874, 8.4 |
||
0915-11 |
HYDRA A (3C218) |
139.52 |
-12.09 |
1.668, 2.28, 4.874, 6.7, 8.4, 12.2 |
||
TAURUS A |
83.63 |
22.01 |
1668 |
|||
1228+127 |
VIRGO A (3C274) |
187.80 |
12.39 |
4.874, 6.7, 8.4, 12.2, 20.346, 20.971, 22, 23.121 |
Freq. band |
Wavelength [cm] |
Freq. range |
Bandwidth |
Central freq. |
---|---|---|---|---|
L |
18 |
1000 - 2000 |
1668 |
|
S |
13 |
2000 - 4000 |
2280 |
|
C |
6 |
4000 - 8000 |
4800, 5040 |
|
X |
3.5 |
8000 - 12000 |
8280, 8400 |
|
Ku |
2.5 |
12000 - 18000 |
12218, 12178 |
|
K |
1.3 |
18000 - 23000 |
23000 |
The radio astronomy flux-density scale has long been based on the polynomial expressions given in Ott et al. (1994) .
The flux density
equation
To calibrate HartRAO data, select one of the following paths: