The ecliptic is the true ecliptic of date. The Z axis is parallel to the rotation axis of the Earth and the Y axis completes a right-handed orthogonal coordinate system. As mentioned above, the X axis is the direction of the mean vernal equinox of J2000. The Z axis is also defined as being normal to the mean Earth equator of J2000. Again this is a right-handed orthogonal coordinate system.
Attitude files The attitude files provide information about the pointing of the spacecraft.
They contain pointing information in 10-minute intervals. The CDF files themselves have all the information to interpret the contents. 0.00000 The SOHO Definitive Attitude files are also available in FITS format, with a binary table extension. There is a row for each 10-minute entry. In addition, and to fulfill the requirements from the helioseismology experiments on-board, full time resolution attitude are availble.