The following table shows when the major STEREO repointings occured.
| Ahead | Behind | |||
|---|---|---|---|---|
| Date | x0 | y0 | x0 | y0 |
| 26 Oct. 2006 | 0.0 | 0.0 | 0.0 | 0.0 |
| 21 Dec. 2006 | -55.0 | 55.0 | ||
| 03 Feb. 2007 | 0.0 | 106.3 | 0.0 | 69.9 |
| 21 Feb. 2007 | 0.0 | -69.9 | ||
Notes on effects on COR1 background subtraction
The COR1 backgrounds will be less reliable in the periods within about two weeks of a repointing. This is because the monthly minimum backgrounds are generated from 27 days worth of data centered on the date for which the background is generated. Since the data cut off at the repoint, the backgrounds near the repoint date won't contain a full 27 days. Another consideration to consider is that if interpolation is selected, it may actually be an extrapolation close to the repoint, because interpolation is also cut off at the repoint boundary.
There have been a number of contamination events for the COR1 objective on both spacecraft. These are also treated as "repoints" by scc_getbkgimg.pro. The following table shows the various contamination events on the two spacecraft. Generally speaking, a contamination event will affect all /CALROLL backgrounds in the period between calibration rolls which contain the event.
| S/C | Date |
|---|---|
| B | 30 Jan. 2009 |
| A | 19 Apr. 2009 |
| B | 24 Mar. 2009 |
| A | 19 Nov. 2010 |
| A | 12 Jan. 2011 |
| A | 11 Feb. 2011 |
| A | 8 Mar. 2011 |
| A | 5 Dec. 2011 |
| A | 19 Feb. 2012 |
| B | 11 Mar. 2011 |
Some other COR1 events which are treated as repoints by scc_getbkgimg.pro are as follows
19 April 2009: (Both) Change of image size from 1024x1024 to 512x512. The one exception to this is the information from the calibration rolls are propagated across this boundary.
16 March 2012: (Ahead only) Change of exposure time from 1.5 seconds to 1.0 seconds.
