Helios 1 Hourly Trajectory Data

HELTRJCON was also corrected as of this date. Data Parameter Description: NY - YEAR OF THE DATA INTERVAL (LAST TWO DIGITS ONLY). ND - DAY OF THE DATA INTERVAL FROM THE FIRST DAY OF THE ABOVE YEAR, JAN. 1= DAY 1.

NH - HOUR OF THE DAY OF THE DATA INTERVAL. NCARROT - CARRINGTON ROTATION NUMBER AS SEEN BY AN EARTH BASED OBSERVER AT THE START OF THE DATA INTERVAL. SPAU - SPACECRAFT HELIOCENTRIC DISTANCE IN ASTRONOMICAL UNITS.

SECLAT - SOLAR ECLIPTIC LATITUDE IN DEGREES SECLON - SOLAR ECLIPTIC LONGITUDE IN DEGREES HELLAT - SOLAR HELIOGRAPHIC LATITUDE IN DEGREES HELLON - SOLAR HELIOGRAPHIC (CARRINGTON) LONGITUDE IN DEGREES HILLON - SOLAR HELIOGRAPHIC INERTIAL LONGITUDE IN DEGREES WITH RESPECT TO ASCENDING NODE OF SOLAR EQUATOR ON THE ECLIPTIC ESSCSANG - EARTH-SUN-SPACECRAFT SEPARATION ANGLE (IN DEGREES, 0-360). ICODE - DATA CODE: 1 MEANS PLASMA DATA ONLY ARE PRESENT FOR THAT HOURLY INTERVAL; 2 MEANS MAGNETOMETER DATA ONLY; 3 MEANS BOTH PLASMA AND MAGNETOMETER DATA PRESENT.

Note 1: The solar ecliptic coordinates are given with respect to true equinox and ecliptic of date. The solar ascending node was located at ecliptic longitude +74.367 degrees as of 1 Jan. 1900 at 1200 UT; this longitude increases by 1.4 degrees/century. Note 2: The solar ecliptic cordinates in this directory before 6/14/94 were calculated incorrectly and have been corrected as of this date.

The heliographic angles are from the original source dataset and had no problems.