To measure the pixel locations (i.e. array orientation, scale) as a function of scan mirror angle for the 160 micron array. The goal of this task is to estimate the location of the 160 micron prime frame with repsect to the telescope boresight. The location of the MIPS instrument frames are found in the frame tables and are given as brown angles. In order to estimate the instrument pointing frame (IPF), a combinations of spacecraft moves and mirror motions places the star on several locations on the array. In addition, these observations are "sandwiched" between observations of stars with the two PCRS. The MIPS team calibrates data and centroids the star on the 160 micron array. These centroided values are passed to the IPF team who uses observations of stars with the PCRS to provide the final calibration and estimate brown angles need to locate the instrument frame.
This focal plane survey the first survey done after spectral leak problem was discovered.
For reasons still not understood the target did not step across the array as we had expected. The target started farther off the array than expected. Therefore, after all the steps were done the target did not adequately cross both rows for the pixel size to be determine. J Morrison just assumed a y pixel size of 17.9 arc seconds (code-V results) and used the 160 centroid routine to find the centroids. The IPF team used these centroids to determine corrections to the brown angles. The brown angles from this run were used for FTU 16.
The brown angles the IPF team found are:
The roughly 45 arcsecond change (about 3 pixels) in theta_Y was a result of previous surveys centering on the spectral leak.
For a complete summary of frame table updates see :
Frame Table Updates: Meta task 2080
