1. Lessons learned from station calibration
Parisa Noorishad, Arnold van Ardenne and Thijs van der Hulst AAVP2011, 12th- 16th Dec Dwingeloo- The Netherlands
Parisa Noorishad AAVP2011, 12th- 16th Dec Dwingeloo- The Netherlands

2. AA-station calibration (gain calibration)
Aim: receivers' DI-complex gain
Methods used by far:
Model-based methods (covariance fitting)
Holographic method
Redundancy (in case of a regular array)
Deterministic effects not to dismiss:
Non-identical beam of the station elements
Beamformed beam of the station elements (complex weights of digital beam)
Beam projection/sky rotation
...

3. Some Demonstrations

4. 1.1 Non-identical beams

5. 24th Nov 2009 21:29:04 UTC, observing CasA
1.2 Non-identical beams
24th Nov :29:04 UTC, observing CasA

6. 2.1 Complex weights of digital beam
Digital Beamforming weights f= 160MHz

7. 2.2 Phase of DI-complex gain
Tracking CasA, 24th Nov 22: 12: 19 UTC

8. 2.3 Phase of DI-complex gain
Tracking CygA, 28th Nov. 19: 55: 54 UTC

9. Suggestions for AA- gain calibration
Not to accept any direction dependency or rapid variations over time or frequency in our gain calibration results.
To know the deterministic effects (e.g. beam shape) well and separate them from the stochastic ones (e.g. correlated noise, ionosphere, etc.).
To know the beam by EM-studies.
To set identical beams as a figure of merit.
To correct for them (especially beam effect)
This hopefully leads to less variance on our parameters of interest in AA-calibration.