Characteristics

The Transition Region and Coronal Explorer (TRACE; Handy et al. 1999a) is a single-instrument 0.3 m Cassegrain telescope capable of imaging the solar atmosphere in a temperature range of 6 x 10³ - 1 x 10⁶ K at a spatial resolution of 1" (pixel size 0.5), equivalent to ~ 770 km on the sun, with typical temporal cadence of 20-40 s. It was launched on a Small Explorer spacecraft from a Pegasus XL vehicle on 1998 April 2 into a geo-polar orbit. As such it provides uninterrupted observations for a 9-month period, followed by a 3-month partial eclipse. The TRACE orbit passes through the South Atlantic Anomaly (Sherrill 1991) and auroral radiation belts, which limit the duration of continuous observation sequences.