Second Microtest Set

GPC1_BrightStarAstrometry_MT2_Noise

This data set consisted of two exposures taken with the default voltages, one with the microtest 05 voltages (SW_L = default - 1.0 V, SW_H = default - 1.0 V), and six others that vary only SW_L or SW_H (with the other set to the default value). To study the impact of these changes, I reduced the data as before, and found the best fit lines in the dx and dy offsets as a function of instrumental magnitudes. The data were binned using 0.1 magnitude bins, and the fit performed between -14 and -12 (other fits were performed using ranges (-16:-14) and (-12:-10), but are not shown here).

The following images show the best fit slopes as a function of voltage in both dx and dy directions, with the dy data providing a control. These show convincingly that SW_L has little effect on the slope within this range, but SW_H values below -0.5 decrease the slope significantly. Since the microtest 05 voltages changed both SW_L and SW_H, there is a jump between the two slope values at SW_L = -1.0V. The two points that comprise this jump are from microtest05 (the smaller slope) and from microtest18 (which varied only SW_L and so still has a larger slope). Comparing the 2-phase and 3-phase devices show that the 3-phase devices have generally acceptable slopes regardless of SW_L and SW_H.

OTA33 / 3-phase	OTA34 / 2-phase

Mosaic of all OTAs. Click to see most legible version that fits under the wiki 2MB filesize limit.

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