ACA High Background Monitor
Back to top index

High background events in dwell 2022:311:14:14:40.151 obsid 45091

Full Dwell Plots

The plots below show the background behavior in each image slot and the overall kalman star count in the OBC during the dwell. For observations with 6x6 image data, a plot is included (BGDAVG) of the telemetered image background avg. For observations with 8x8 image data, a plot is included (corr background 8th outer min) which includes an estimate of the per-image background level taken from the edge pixels. For that metric, for each image, the edge pixels used in the dynamic background (edge pixels + the corners of the 6x6) are sorted and the 8th lowest value is used. A small correction value is also subtracted for images with very bright stars. The corrected 8th outer min is just called "outermin" in the pixel image plot lower on the page if present.

In the plot, any Y values beyond the max of the Y axis are clipped to the max value and plotted with black arrows.

In the background plots, the top five high background events are marked with red background rectangles. The top events are selected by the maximum background values. Other events beyond the top 5 are marked with grey rectangles. An event is defined as the period of time when the background is above the threshold (580 e-/s for BGDAVG and 140 e-/s for the corrected 8th outer min) for 3 image samples within 21s. Events within 90 seconds are combined into single events (and may have values below the threshold). The top 5 events are the same events used for the pixel data plots below.

For these full-dwell plots, to reduce plot size and loading time, the plots are binned by time. For the background plots, the maximum value in the bin is plotted. For the AOKALSTR plot, the minimum value in the bin is plotted.

aca_view for full dwell

aca_view --start 2022:311:14:14:40.151 --stop 2022:311:17:03:30.227

Pixel Data for up to 5 events in the dwell

The animation below shows the pixel data for up to 5 events in the dwell. The images are intended to show display from 10 seconds before to 10 seconds after the event. If the event is more than 300 seconds long, the animation will be truncated.

Event 0 starting at 2022:311:15:46:01.003

aca_view --start 2022:311:15:46:01.003 --stop 2022:311:15:50:37.753
event start 2022:311:15:46:01.003 duration 276.8s