Alt vs Az plots » History » Version 3
Aaron Roodman, 11/19/2012 06:21 PM
h1. Alt vs Az plots
Here are plots of the Donut measured x and y decenter (DODX and DODY) vs. AltAz. The axis are actually a flattening of the sphere - cos(alt)sin(az) vs. cos(alt)cos(az).
These plots are for images between 11/11 and 11/17, and removing 11/15 which did not have the Telescope LUT working. Also I require exptime>=10 sec and not u filter. Note that both DES and community images are included, but that only a small range of values of Alt-Az have actually been explored.
There isn't a wide enough range of positions to draw clear conclusions, however, the same trajectory is imaged over different nights, giving some repeat views of places on the sky. You can see from the color scale (its in microns of decenter) that the results are reasonably repeatable. There is no sign of any large hysteresis effect in this limited view.