Tohban Links: Basic Information on Decimation

This page gives only a short overview of currently used count rate decimation.
For a more detailed discussion and log go to Decimation settings log.
Currently Used Decimation Tables

Science#: Front / Rear
12: Normal / Normal
13: Active / Normal
16: Quiet/CRAB / Normal
17: Normal / Vigorous
18: Active / Vigorous
19: Normal / Active
20: Active / Active
21: Quiet/CRAB / Vigorous
22: Very Quiet / Normal
23: Very Quiet / Active
24: Very Quiet / Vigorous

For a full list of "science numbers" (decimation identification number in the data packets) and instructions on how to read them from the data files go to Conversion Table Between IDPU Version # and Decimation Table ID.

Front Segments

The decimation depth and the top decimated energy level depend on the SSR level and the attenuator state. The tables used are:

Quiet/CRAB:T5 ("Crab Ops")
Very Quiet:T6 ("Very Quiet Sun")
Normal:T3 ("Quiet Sun")
Active:T4 ("Active Sun")

Rear Segments

The rear segments are decimated at high-magnetic-latitude zone ONLY (day or night). The used tables of top decimated energy level and decimation depth are:

Normal: decimation below channel 4*128 (approx. 195 keV), 3/4 removed (code: 43)
Active: decimation below channel 8*128 (approx. 390 keV), 3/4 removed (code: 83)
Vigorous: decimation below channel 8*128 (approx. 390 keV), 5/6 removed (code: 85)

Last update: 2007-05-16, Jim McTiernan