File: ulymgd.txt ------------------------------------------------------------------ MERGED ULYSSES DATA DESCRIPTION This directory contains hourly averages of parameters for the interplanetary magnetic field, solar wind plasma, daily COSPIN fluxes and spacecraft trajectory coordinates. Principal Investigator of magnetic field data: Dr. A. Balogh, Imperial College, London, UK Principal Investigator of plasma data, Dr. John L. Phillips Los Alamos National Laboratory The daily-averaged fluxes are from the LET (Low Energy Telescope; R.G. Marsden, ESTEC) and HET (High Energy Telescope; R.B. McKibben, UNH) components of the COSPIN (COsmic ray and Solar Particle INvestigation; R.B. McKibben, UNH) package flown on the Ulysses spacecraft. ULYSSES data have been reprocessed to ensure a uniformity of content and coordinate systems relative to data from other deep- space missions: - All spacecraft trajectory data were transformed to a Heliographic Inertial (HGI) coordinate system. - calculation of RTN Spherical components of the solar wind velocity from RTN cartesian components: - merging of trajectory coordinates, magnetic field data, and plasma data files into a single annual file ULY_YR.DAT, where YR is the year; - Data gaps were filled with dummy numbers for the missing hours or entire days to make all files of equal length. The character '9' is used to fill all fields for missing data according to their format, e.g. ' 9999.9' for a field with the FORTRAN format F7.1. Note that format F7.1 below really means (1X,F6.1),etc. Note that an COHOWeb interface to this dataset, providing data subsetting and and graphical browsing, is available at "http://omniweb.sci.gsfc.nasa.gov/coho/" For the daily resolution data (one file), simple averages were taken over the hourly values. The format is identical to that for the hour averages However, the "hour" field has 0 as a value.and the "Magnitude of Average Vector" field is the simple average of the 24 hourly values of this parameter. FORMAT DESCRIPTION WORD ASCII MEANING UNITS/COMMENTS 1 I4 Year 1992, 1993, etc. 2 I4 Decimal Day January 1 = Day 1 3 I3 Hour 0,1,...,23 4 F7.2 Spacecraft Heliographic Astronomical units distance 5 F7.1 Heliographic Inertial latitude Degrees, +/-90. of the Spacecraft 6 F7.1 Heliographic Inertial longitude Degrees, 0-360 of the Spacecraft 7 F7.2 BR RTN-Coordinate System nanoteslas 8 F7.2 BT RTN-Coordinate System nanoteslas 9 F7.2 BN RTN-Coordinate System nanoteslas 10 F7.2 Field Magnitude Average |B| 1/N SUM |B|, nT (B-scalar) 11 I5 Number of vectors for Number Mag field to the average 12 F7.1 Plasma flow speed, RTN km/s 13 F7.1 THETA-elevation angle degrees of flow velocity vector (RTN-cordinate system) 14 F7.1 PHI- azimuth angle of degrees flow velocity vector. (RTN-coordinate system) . 15 F9.5 Proton density [n/cc] 16 F9.5 Alpha density [n/cc] 17 F9.0 Proton Temperature (Large) degrees, K 18 F9.0 Proton Temperature (Small) degrees, K 19 E10.3 2.0-4.0 MeV H flux COSPIN,LET (1/(sec-cm**2-ster-MeV) 20 E10.3 4.0-6.0 MeV H flux COSPIN,LET (1/(sec-cm**2-ster-MeV) 21 E10.3 6.0-8.0 MeV H flux COSPIN,LET (1/(sec-cm**2-ster-MeV) 22 E10.3 8.0-16.0 MeV H flux COSPIN,LET (1/(sec-cm**2-ster-MeV) 23 E10.3 16.0-20.0 MeV H flux COSPIN,LET (1/(sec-cm**2-ster-MeV) 24 E10.3 39.0-70.0 MeV H flux COSPIN,HET (1/(sec-cm**2-ster-MeV) 25 E10.3 71.0-94.0 MeV H flux COSPIN,HET (1/(sec-cm**2-ster-MeV) * Originally COSPIN fluxes have 24-hr resolution The difference between T (Large) and T (Small) is discussed at ftp://spdf.gsfc.nasa.gov/pub/data/ulysses/plasma/swoops/ ion/swoops_ion_users_guide_update_20030214.txt DESCRIPTION OF COORDINATE SYSTEMS The Heliographic Inertial (HGI) coordinates are Sun-centered and inertially fixed with respect to an X-axis directed along the intersection line of the ecliptic and solar equatorial planes. The solar equator plane is inclined at 7.25 degrees from the ecliptic. This direction was towards ecliptic longitude of 74.36 degrees on 1 January 1900 at 1200 UT; because of precession of the celestial equator, this longitude increases by 1.4 degrees/century. The Z axis is directed perpendicular and northward from the solar equator, and the Y-axis completes the right-handed set. This system differs from the usual heliographic coordinates (e.g. Carrington longitudes) which are fixed in the frame of the rotating Sun. The RTN system is fixed at a spacecraft (or the planet). The R axis is directed radially away from the Sun, the T axis is the cross product of the solar rotation axis and the R axis, and the N axis is the cross product of R and T. At zero Heliographic Latitude when the spacecraft is in the solar equatorial plane the N and solar rotation axes are parallel. ------------------------------------------