Changes between Version 2 and Version 3 of GPC1_BrightStarAstrometry_SW_LH_scan

Timestamp:

Apr 20, 2011, 7:20:05 PM (15 years ago)

Author:

watersc1

Comment:

--

GPC1_BrightStarAstrometry_SW_LH_scan

@@ -3 +3 @@
 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.  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.
+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               ||