Ulysses Cosmic Ray and Solar Particle Investigation (COSPIN) High Energy Telescope (HET) Full Resolution Electron Counts and Accumulation Times for Eight-Sectored Coincidence Counting Rates, SECT1 H7S, 64 s Data

A Directory containing Daily FTP downloadable Files containing Readout-by-Readout Listings of the Counts accumulated in each Spin Sector of the Eight-Sectored H7S Counting Rate. Aside from its Division of Counts into Spin Sectors, H7S is a Coincidence Counting Rate with Coincidence Logic Requirements identical to the Spin-Averaged Counting Rate H7. Therefore both the H7 and the H7S Counting Rates respond primarily to Electrons in the very approximate Energy Range from about 5-10 MeV. The Naming Convention for the Daily Files is uly_het_full_rat_sect1_YYYDDD.txt, where YYY indicates the three digit Year since 1900 (e.g. YYY=090 for 1990, and YYY=102 for 2002) and DDD indicates the three digit Day of Year (January 1 = 1). In each File, following a detailed Description of the Format, the Data consist of a Readout by Readout Listing of Counts accumulated in the eight 45° Spin Sectors of the Sectored Counting Rate H7S during the Intervals between successive Readouts, organized into Columns as described below. The first four Columns give the Start Time of the Counting Rate Accumulation Period for Sector 7 of the Rate as Fractional Year (to 12 Decimal Places) and as Year since 1900, Day of Year, and Milliseconds of Day at the Start of the Accumulation, followed by one Column (labeled cov) giving the Duration of the total Accumulation Period for all eight Sectors in Milliseconds. Thus the Accumulation Period in each of the Sectors is the Value given in the "cov" Column divided by eight. The Accumulation in each of the successive Sectors 7,8,1,2,3,4,5, and 6 starts cov/8 Milliseconds after the Start of the Accumulation in the previous Sector. Columns 6-13 then give the Counts accumulated in each of the eight Sectors during the Accumulation Period. Each Line contains Data for one single Readout Accumulation of the eight Sectors of H7S. Since the Accumulation Period for each Readout is forced to include an Integral Number of Spacecraft Spins in order to produce equal Coverage in all Sectors, the Lengths of the Accumulation Periods vary in a Cyclic Manner as the Period of the Telemetry Cycle beats with the Spacecraft Spin Period. The H7S Counting Rate is fully read out every 64 s at the most common Science Telemetry Bit Rate (2048 bps). Thus, with a typical 5 rpm Spacecraft Spin Rate the Accumulation Intervals vary in a repeating Cycle of 60, 60, 72, 60, 60, 72, 60, etc., seconds. At lower Bit Rates the Average Interval is equal to 64 times (2048/BR) seconds and the Cycle automatically adjusts to produce this Average Accumulation. The Spin Plane of the Ulysses Spacecraft, in which the Sectors are defined, is normal to the Spin Axis (Spacecraft +Z Axis), which is maintained within one to 2° of Earth pointing at all Times. Viewed from Earth the Spacecraft spins Counter Clockwise. The Start of Sector 1 is defined by the Spacecraft Generated Sun Pulse, which is issued when the Sun crosses the +X/+Z Quadrant of the X/Z Plane. The HET Telescope Axis is parallel to the +X Axis and normal to the Z Axis. No Noise Removal or Despiking has been done, so Caution must be used in interpreting isolated large Increases or Decreases in the Counting Rates.

Tags: energeticparticles
Organization: National Aeronautics and Space Administration