UVS Data Handling & Safety: UVS

Photons are recorded as (x,y,z) events in “pixel list mode” with time hacks every few ms; events & time hacks each use 24 bits; 11 bits spectral (i.e., 0-2047 values), 8 bits spatial (i.e., 0-255 values), and 5 bits for pulse amplitudes (i.e., 0-31 values)
Alternating “ping-pong” buffers allow continuous observations; 32K-event frames are sent to the S/C on the high-speed science line (2 Mbits/s; transfer time 0.39 s) as soon as they are filled with events & time hacks
A data quality (DQ) index, based on the expected count rate, is written to the header for each frame; this allows for the selection of the “best” 500 Mbits of data acquired during each orbit for transmission to the ground
In regions of high particle background, the count rate may exceed the maximum allowed count rate of ~106 counts/s; when this occurs the UVS high voltage is immediately (i.e., within 0.1 s) lowered for safety
After safing, UVS will attempt to autonomously ramp high voltage back up after a configurable delay (2-500 s)

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Last updated: 08/30/2016