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Wavefront sensing

New wavefront sensing data were taken in February 2003 to determine the aberrations of the primary mirror. The data was analyzed and compared to the data taken in March 2002. In general the results agree, with the focus, astigmatism, and spherical aberrations showing clear dependence on zenith distance. However, there are some (mostly detailed) differences between the results. Considering that in between the tests the main mirror has been taken-out for aluminization and we have had the problems with the mirror support pads, we want to double check these difference and we have additional tests scheduled for April the 11th.

The fact that no very big differences exist between the two tests does show that no major changes have occurred due to the aluminization or the problems with the mirror pads.

Thomas Augusteijn 2003-05-08