| | 2 | |
| | 3 | == New thoughts: 2014-01-13 == |
| | 4 | |
| | 5 | After the Taiwan meeting, I spent some time thinking about this problem again, and came to the following conclusions. |
| | 6 | |
| | 7 | The reason the background restored images do not look usable below is due to the fact that the background is comprised of more components that the original assumption allowed. I'm now fairly confident that the background model solution is |
| | 8 | B_model = B_OTA + B_astronomical + B_transparency |
| | 9 | where B_OTA is an OTA-specific background model that is created by the PATTERN.CONTINUITY code. This forces all the cells to have a co-planar background, in order to prevent cell-edge background residuals. This B_OTA is assumed to be stable, and some quick checks indicate this isn't completely unreasonable. Therefore, in order to combine the background models, this needs to be removed from the model (possibly by simply removing the common plane calculated for each OTA). |
| | 10 | |
| | 11 | The next conclusion was that it's probably excess work to construct warp stage models. We can instead use the chip stage products and transform the individual points from each to the warp grid. This will create an irregular grid of points, which leads me to suggest using thin plate splines to do the interpolation to the stack grid. This interpolation also allows for outlier rejection by constraining the allowed bending energy of the spline. |
| | 12 | |
| | 13 | Gene has mentioned that B_transparency may also complicate this. However, if we fold this into the ppStack code, we can use the fact that we measure the relative zeropoints for each input, and filter the inputs to ensure that the differences in B_transparency do not skew the calculated B_astronomical. |
