The positions offsets for the various locations (A1-A6) were checked
using the central dipole and the interim correlator. Crosses were done
(+/- 3 hpbw) with a strip in azimuth followed by a strip in za (each
one minute long). Data was taken 21jun10 thru 25jun10. All the data was
taken with the single pol array. 2-d gauss fits were made to the
crosses fitting for:
- baseline offset,src amplitude,az,za
offsets,width1,width2,rotation angle of ellipse
The plots show the az, za offsets from
the fits (.ps)
- Page 1: the measured position errors from the fit:
- the positions are color coded: A0:black,A1 red,A2 green,A3
blue,A4 purple,A5 dark red, A6 light blue (see next page for color
- top 2: za Error vs za and az
- bottom 2: az Error vs za and az
- These are the errors from the cross fit. The sky position
offsets for the beam centers would be minus these numbers.
- Errors in beam 0 will affect all other beams. The compute the
offset in beam N you need to first subtract the error in position 0.
- Page 2:
- arrow plot showing the fit errors vs az,za.
- The table at the top show the mean and rms error in az,za for
each position (in arc seconds)
- Page 3:
- + Plot of the beam centers on the sky used jun10
- * Plot of beam centers after correcting for the pointing
- The table shows the beam center offsets from beam A0 (on the
sky) after correcting for the measured pointing error.
Table of position offsets from beam A0 (on th sky in arc minutes).
- Used are the values used 21jun10 thru 26jun10
- Corrected: the values after correcting for the measured pointing
errors (these are the values that should have been used.
Jun10 position offsets
(Amin). used and corrected